It is advisable to first analyze the terminology applied to this movement. Except for small nuances, in general it can be considered that rationalism, International Style and Modern Movement are synonymous concepts.[1][2][3][4] As its etymology indicates, rationalism comes from reason and has its origin in the claim of the new architecture to rationalize construction processes. Rationalism was the heir of the Enlightenment and the Industrial Revolution, the culmination of a long process of application in architecture of the new mechanization processes initiated with the industrial era. This process evolved in parallel to social advances, with a certain utopian component of application of the values ​​of architecture and urbanism to the improvement of society: industrialization, used in a "rational" way, would serve, according to the theorists of the movement, to solve social injustices and create an urban environment that optimally encompasses the majority of the population.[5] Some historians point the origin of the term to this phrase by Erwin Piscator:

The term "International style" (in English: International style) comes from the exhibition Modern Architecture - International Exhibition organized by Henry-Russell Hitchcock and Philip Johnson at the Museum of Modern Art (MoMA) in New York in 1932 and in the book published by both The International Style: Architecture since 1922. Despite its ambiguity, the term made a fortune and is the most used in the Anglo-Saxon world to designate the most orthodox phase of rationalism. For Hitchcock and Johnson, the International Style encompassed the most symptomatic productions of both rationalism and neoplasticism, characterized by a rational language based on industrial production.[7]​ Sometimes the term rationalism is limited to Europe, while International style would describe it worldwide.[8]​ Another term used in this context is "internationalism", from the book Internationale Architektur by Walter Gropius (1925).[9]​.

The term "Modern Movement" (in English: Modern Movement) comes from the book Pioneers of Modern Movement from William Morris to Walter Gropius (1936), by Nikolaus Pevsner, and would be more inclusive, since it would bring together rationalism with expressionism, cubism, futurism, neoplasticism and constructivism "Constructivism (art)"), generically considered as a "pre-rationalism" (or "protorrationalism"). The author's intention was to point out the convergence of several stylistic currents towards a new way of conceiving architecture during the first decades of the century. According to Pevsner, "it is essential to understand the Modern Movement as a synthesis of the Morris movement (Arts & Crafts), the development of steel construction and art nouveau." It is interesting to note that already in 1902 the architect Otto Wagner had used the same term in the preface to his book Moderne Architektur.[10] However, in recent times some historians have criticized some of Pevsner's formulations, especially regarding the alleged loss of historical roots in modern architects, pointing out for example that Le Corbusier was largely inspired by classical Greco-Roman architecture and Ludwig Mies van der Rohe in the work of the neoclassical architect Karl Friedrich Schinkel. Another of the premises questioned has been that of a common supranational style, against which a wide divergence of nationally based criteria has been pointed out in each of the countries where the movement developed, although on numerous occasions they converged on common criteria. Thus, compared to the initial postulates of Pevsner and Siegfried Giedion, from the 1970s onwards various historians criticized the concept of the Modern Movement, such as Reyner Banham, Bruno Zevi or Manfredo Tafuri, while Charles Jencks began to speak of "modern movements" in the plural.[11]​.

It should be noted that in some countries, especially in the Anglo-Saxon sphere, the term "modernism" is used synonymously with the Modern Movement. However, in Spanish this term is used for the artistic style "Modernism (art)") developed between the end of the century and the beginning of the century also known as art nouveau in France, Modern Style in the United Kingdom, Jugendstil in Germany, Sezession in Austria, Nieuwe Kunst in the Netherlands or Liberty in Italy.[12]​.

Finally, it should be noted that Modern Movement is not the same concept as modern architecture, which is the architecture of modernity, a cultural process that began with the Enlightenment in the century based on science and progress, linked to philosophical positivism. It therefore includes the centuries , and , that is, until the present day, because although postmodern art has questioned the validity of modernity since the 1980s, historians do not agree, and there are even experts—such as Valeriano Bozal—who point out that postmodernism is just another phase of modernity, precisely the one in which it reflects on itself.[13]​.

Contenido

Los orígenes del racionalismo son difusos y proceden de una lenta evolución desde mediados del siglo hasta los años 1920, en que empezó a cobrar conciencia en una nueva generación de arquitectos, críticos y estudiosos de la arquitectura la constatación de que las realizaciones de esa época compartían unos rasgos estilísticos comunes y un programa moderno y dinamizador de los procesos constructivos y urbanísticos. En la génesis del racionalismo se encuentran los adelantos tecnológicos que propiciaron en la segunda mitad del siglo la arquitectura de cristal y hierro, el movimiento Arts & Crafts, la edificación de los primeros rascacielos propiciada por la Escuela de Chicago "Escuela de Chicago (arquitectura)"), la formulación de la teoría funcionalista "Funcionalismo (arquitectura)") por Louis Sullivan, algunos postulados de la arquitectura modernista —especialmente la Sezession vienesa— y la obra de varios arquitectos individuales —en especial Frank Lloyd Wright— hasta desembocar en las corrientes de vanguardia de inicios del siglo , que suelen considerarse como un prerracionalismo.[15]​.

Hay que considerar también como motor de la nueva arquitectura en la transición entre los siglos y los cambios tecnológicos producidos en la llamada Segunda Revolución Industrial, tales como la invención del hormigón armado (1854), el procedimiento Bessemer para la elaboración del acero (1856), la invención de la dinamo "Dinamo (generador eléctrico)") para generar electricidad como fuerza motriz (1869), el teléfono (1876), los experimentos de Galileo Ferraris sobre el campo magnético rotatorio que permiten el transporte a distancia de la energía hidráulica (1883), la bombilla eléctrica (1879), el motor de explosión (1885), etc. Todos estos factores ayudaron a la industria de la construcción y lanzaron a la arquitectura a una nueva forma de construir de múltiples posibilidades.[16]​.

Un primer factor determinante en la aparición del racionalismo fue la apertura en 1919 de la Bauhaus, una escuela de arquitectura, arte y diseño dirigida por Walter Gropius que preconizaba un estilo funcionalista de líneas sencillas y basado en la producción industrial. Durante los años posteriores al fin de la Primera Guerra Mundial empezaron a descollar varios arquitectos que fomentaban en sus obras las premisas racionalistas, como el propio Gropius, Le Corbusier y Ludwig Mies van der Rohe, considerados los máximos exponentes de este movimiento, que ayudaron a su difusión internacional. Poco a poco el nuevo estilo se fue difundiendo gracias a concursos, congresos y exposiciones: en 1922, el concurso para la nueva sede del Chicago Tribune dio a conocer propuestas de Gropius, Adolf Meyer "Adolf Meyer (arquitecto)"), Max Taut y Hans Scharoun; en 1925, Le Corbusier construyó para la Exposición de Artes Decorativas e Industrias Modernas de París el pabellón de L'Esprit Nouveau, en el que expuso sus nuevas teorías urbanísticas; en 1927, la exclusión de Le Corbusier del concurso para la sede de la Sociedad de Naciones en Ginebra provocó un gran escándalo, hecho que repercutió en otorgarle más fama; también en 1927, Mies van der Rohe organizó en Stuttgart una exposición de arquitectura dedicada a la vivienda (Die Wohnung) que promovió la construcción de treinta y dos casas —la urbanización Weißenhofsiedlung—, entre edificios y viviendas unifamiliares, que supuso un gran hito para el nuevo estilo:[17]​ la internacionalidad del proyecto llevó al profesor Paul Schmitthenner") a afirmar que «estamos alcanzando la fórmula del estilo internacional del siglo ».[18]​ Otras exposiciones en las que participaron arquitectos racionalistas fueron: la Exposición Internacional de Barcelona (1929) "Exposición Internacional de Barcelona (1929)"); el Salón de los Artistas Decoradores del Grand Palais de París (1930); y la Bauausstellung (Feria de la Construcción) de Berlín (1931).[19]​.

El mayor acontecimiento que supuso la oficialización del racionalismo fue la fundación en 1928 en La Sarraz (Suiza) del Congreso Internacional de Arquitectura Moderna (CIAM), una asociación internacional de arquitectos encargada de celebrar congresos para debatir los nuevos principios de la arquitectura y ayudar a su difusión internacional.[20]​.

Otro de los principales acontecimientos que ayudaron a difundir el nuevo estilo fue la exposición Modern Architecture - International Exhibition, organizada por Henry-Russell Hitchcock y Philip Johnson en el MoMA de Nueva York en 1932, de la que surgió asimismo el libro publicado por ambos, The International Style: Architecture since 1922, que aportó el término Estilo internacional para designar al movimiento. Estos autores se centraron más en los aspectos formales que unían las diversas manifestaciones de este movimiento que no en sus premisas teóricas e incluso utópicas. Señalaron como principales características de este estilo el rechazo al eclecticismo "Eclecticismo (arte)") historicista, el empleo de materiales como el acero, el vidrio y el hormigón, el uso de la planta libre y la «concepción de la arquitectura como volumen más que como masa».[21]​.

El racionalismo tuvo una rápida difusión por toda Europa y arraigó especialmente en Alemania, Francia, Países Bajos, Austria, Checoslovaquia, Suiza, Reino Unido —gracias especialmente a arquitectos alemanes huidos del nazismo—, Italia y España. En los años 1930 el racionalismo tuvo un nuevo centro difusor en Estados Unidos, adonde llegaron numerosos arquitectos europeos exiliados a causa del nazismo alemán, el fascismo italiano y el comunismo soviético.[22]​ Sin embargo, en esa década el movimiento entró en una fase de ciertas dudas y de críticas hacia su excesivo formalismo y su frío mecanicismo, alejado de las necesidades humanas. El propio Le Corbusier se fue distanciando de su purismo inicial y empezó a considerar la máquina como una herramienta y no un fin en sí mismo. Pese a todo, el racionalismo continuó siendo el estilo hegemónico a nivel internacional hasta prácticamente los años 1960.[23]​.

Tras la Segunda Guerra Mundial el movimiento comenzó a decaer, pero todavía se siguió construyendo en estilo racionalista hasta los años 1960 e incluso 1970, en convivencia con otros nuevos estilos que fueron surgiendo.[22]​ De hecho, en la posguerra la urgencia de reconstruir las ciudades devastadas en la contienda coadyuvó a la pervivencia del estilo, ya que frente a la búsqueda de nuevos estilos se prefirió uno ya consolidado. Ello se produjo en paralelo a la definitiva universalización del lenguaje racionalista, ya que su mayor difusión en esos años se produjo en países emergentes como Brasil, India, México y Venezuela.[24]​ Esta globalización del movimiento llevó pareja una diversificación del mismo, ya que tuvo que adaptarse a las diferentes tradiciones constructivas de países de muy diversa cultura, así como a diversas condiciones climáticas, económicas y sociales.[25]​ Incluso en Estados Unidos el Estilo internacional se fue regionalizando, como se demuestra por la sustitución en numerosos casos de los esqueletos de acero por madera, por influencia de las casas usonianas de Frank Lloyd Wright.[26]​.

La difusión del internacionalismo tras el conflicto bélico corrió a cargo principalmente de la Unión Internacional de Arquitectos (Union Internationale des Architectes, UIA), fundada por el francés Pierre Vago en colaboración con el inglés Patrick Abercrombie, el italiano Saverio Muratori"), el portugués Carlos João Chambers Ramos y el ruso Viacheslav Popov"); Vago fue su secretario general entre 1948 y 1968. El primer congreso se celebró en París en 1948 y desde entonces cada tres años en un país distinto. Otro órgano de difusión fue la revista Architectural Review, así como instituciones como la Universidad de Harvard, la Ulm Bauhaus y la Architectural Association School of Architecture del Reino Unido, y otras de nueva creación como la Middle East Technical University de Ankara y el Asian Institute of Technology de Bangkok.[27]​.

Sin embargo, tras la contienda mundial el Estilo internacional se fue convirtiendo en un método de construcción sistemático y perdió algo de su esencia inicial y de su componente utópico de un arte al servicio de la sociedad. La confianza en las nuevas tecnologías, en el arte como instrumento de educación para el pueblo, en una estética universal que comportase una ética universal, se fueron diluyendo, y el movimiento se fue reduciendo a un estilo reglamentado, que no dejaba espacio para la innovación ni la creación individual, para la subjetividad o la relación con la naturaleza.[28]​ Su evolución estilística fue hacia un cierto eclecticismo "Eclecticismo (arte)") —según Jürgen Joedicke— o manierismo —según Josep Maria Sostres—, con dos posibles vías de realización: la «imitación mecánica e impersonal de los grandes ejemplos» (Sostres) o la contextualización regionalista, como la practicada por el neoempirismo escandinavo, el brutalismo británico, el neorrealismo "Neorrealismo (arquitectura)") y neoliberty italianos o la Escuela de Barcelona "Escuela de Barcelona (arquitectura)") en España.[29]​.

El principio del fin de este movimiento se escenificó en el IX congreso del CIAM, en el que un grupo de arquitectos disidentes se organizó en el llamado Team X, que propugnaba una evolución hacia un estilo más realista y de utilidad social, que se concretó en un nuevo estilo denominado brutalismo. Este grupo acusaba al CIAM de haber patrocinado el Estilo internacional imponiendo «conceptos mecánicos de orden», sin tener en consideración las necesidades emocionales del ser humano o las especificidades territoriales de los diversos países en que se desarrolló el estilo. El propio Philip Johnson confesó en 1996 que «nuestra así llamada arquitectura moderna era demasiado antigua, glacial y llana».[30]​.

Aunque el fin del racionalismo como estilo puede situarse en el primer lustro de los años 1960, cabe remarcar que hasta los años 1970 y primeros 1980 aún se construyó en ese estilo —de forma más o menos ortodoxa— en numerosas partes del mundo, especialmente en países emergentes que habían llegado con cierto retraso a la modernidad. El proceso descolonizador iniciado en África y Asia tras la Segunda Guerra Mundial propició el auge constructivo de estos nuevos países, que necesitaban nuevas infraestructuras y edificios gubernamentales, y que adoptaron el Estilo internacional como forma de equiparar la construcción de un nuevo estado con una imagen moderna y progresista. En muchos casos, esta arquitectura resultó estereotipada y acontextualizada, con una cierta apariencia de trasplante de tipologías occidentales a países de distinta tradición cultural, sin atender a las condiciones sociales, geográficas y económicas de estos países.[31]​.

CIAM

The International Congress of Modern Architecture (in French: Congrès International d'Architecture Moderne) was founded in La Sarraz (Switzerland) in 1928 to promote interaction between architects and urban planners from around the world in order to exchange ideas and compare the styles and techniques used in different places around the world.[32] Originally, the meeting was motivated as a response to the postponement of the Modern Movement in the competition for the headquarters of the League of Nations in Geneva, against which the architects of the new movement wanted to offer a common front.[33]​ Among the founders of CIAM was Le Corbusier,[note 1]​ and Siegfried Giedion was its first secretary until 1956.[35]​ As the executive body of CIAM, CIRPAC, the International Committee for the Resolution of Problems of Contemporary Architecture (in French: Comité International pour la Résolution des Problems of Contemporary Architecture). In 1959 its final dissolution occurred; By then the congress had more than thirty affiliated countries and about three thousand members.[36]​.

Four phases are usually noted in the history of the CIAM: the founding cycle of the congresses (1928-1933), the crisis motivated by Nazism and the series of emigrations of numerous architects (1934-1945), the refoundation and expansion of the congress (1945-1953) and the process of agony of the movement motivated by the protest process of the youngest architects. (1953-1959).[33]​.

At their first meeting, Le Corbusier was in charge of drafting the agenda to be discussed, which included the following topics: modern technology and its consequences; standardization; the economy; urban planning; youth education; the realization: architecture and the State.[37] A declaration was drafted that maintained that "to benefit a country, architecture must be closely related to the general economy. True performance will be the result of rationalization and standardization, and sufficient production to fully satisfy human demands."[38] Three functions were also identified as primary objectives of urban planning: living, working, entertainment.[39]​.

In 1929 the second congress met in Frankfurt (Germany), focused on the issue of "minimum housing." CIAM III took place in 1930 in Brussels (Belgium), on the "rational urbanization" of space. The fourth congress, dedicated to the "functional city", was to be held in Moscow, but for political reasons it was finally held in Athens (Greece) in 1933, aboard the yacht Patris II; In it the so-called Letter of Athens was agreed. In 1937 CIAM V was held in Paris (France), under the premise of "housing and leisure." The Second World War paralyzed the congresses and fostered the rise of the American group; Josep Lluís Sert, exiled in that country, published the book Can Our Cities Survive? in 1943, where he collected the postulates of the CIAM and became the reference work of rationalism in the Anglo-Saxon sphere. After the war, CIAM expanded to Asia, Africa and Latin America, and the Le Corbusier-Gropius-Giedion trio began to lose influence. In 1947 CIAM VI took place in Bridgwater (England), focused on the reconstruction of cities devastated by war. CIAM VII was held in Bergamo (Italy) in 1949, on architecture as art. In 1951, CIAM VIII was housed in Hoddesdon (England) and focused on the center of the city, with a first split between orthodox and innovative positions due to the approach of new concepts such as the symbolic dimension and the human scale. CIAM IX took place in 1953 in Aix-en-Provence (France) and focused attention again on generational disputes and the founding of Team X by Jaap Bakema, Georges Candilis, Aldo Van Eyck and Alison and Peter Smithson. In 1956 CIAM X was held in Dubrovnik (Yugoslavia), focused on the as an alternative to that of Athens. In 1957 the national groups were dissolved and Jaap Bakema was elected general secretary. The last congress, CIAM XI, took place in 1959 in Otterlo (Netherlands) and meant the dissolution of CIAM.[40]​.

The MoMA exhibition of 1932

The exhibition Modern Architecture - International Exhibition was held at the Museum of Modern Art (MoMA) in New York between February 9 and March 23, 1932. It subsequently toured the United States for six years.[41] Its curators were the critic Henry-Russell Hitchcock and the architect Philip Johnson, who chose the most representative works of the new style in Europe and the United States—with the only exception outside these continents of the laboratory building of electricity from the Ministry of Public Works in Tokyo, by Mamoru Yamada. The selection criteria were basically aesthetic, which is why they left aside the most programmatic aspects of the new architecture, especially its social and economic dimensions, a fact for which Hitchcock and Johnson's proposal was criticized. According to the curators, the works included in the new trend had to meet a series of parameters, such as the absence of ornamentation, the composition in terms of volume and not mass, in modular regularity and not in axial symmetry. As for architects, they left out the work of the movement's pioneers, such as Peter Behrens, Auguste Perret, Adolf Loos, Antonio Sant'Elia and Frank Lloyd Wright, and established Le Corbusier, Walter Gropius, Ludwig Mies van der Rohe, Jacobus Johannes Pieter Oud, Gerrit Rietveld and Richard Neutra as paradigms of the new movement.[42]

The work of sixty-seven architects was exhibited.[note 2]​ The majority of projects exhibited came from Germany, followed by the United States. By architects, the majority were projects by Gropius, Le Corbusier and Mies van der Rohe. The selection was made by the curators themselves, whether they were projects that they were familiar with or one of them, with few exceptions of recommendations from other people they trusted, such as Richard Neutra, who recommended the Tokyo electrical laboratory, by Mamoru Yamada, or Bruno Taut, who recommended the Moscow electrophysical laboratory, by Iván Nikolayev and Anatoli Fisenko").[44]

With the same premises as the exhibition, Hitchcock and Johnson published the same year the book The International Style: Architecture since 1922, which gave its name to the movement in the Anglo-Saxon world. In the book they analyzed the work of seventy-two architects from fifteen countries, with the premise that they represented a new architectural style of an international nature. In the foreword, MoMA director Alfred Barr noted that the authors had demonstrated that "there is today a modern style as original, consistent, logical and international as any in the past."[45]

In 1951, Hitchcock made the following retrospective analysis of the parameters used for the exhibition:

Philip Johnson also reviewed the parameters of the exhibition in the 1960s and pointed out as the main characteristics of the International Style structural honesty, repetitive modular rhythms, flat ceilings, clarity expressed by glass surfaces, the box as a container and the absence of decoration.[46]​.

Rationalism was a heterogeneous movement with both geographical and chronological origins that were difficult to pin down. It could be said that it was rather a confluence of different styles that converged on common characteristics, which became more clearly evident after the First World War. Its general characteristics were forged little by little in the work and contributions of all the movements and architects that are considered antecedents of this style. When these characteristics were analyzed more thoroughly, it was possible to determine that the majority of creations of this new style were based on several main points: use of a functionalist language, use of simple geometric shapes and regular structures, tendency towards a vertical-horizontal arrangement, renunciation of ornamentation and use of industrial-type materials (concrete, steel, glass).[47] Despite this, it is difficult to speak of a homogeneous style and, in fact, many rationalist architects stated that they did not They had style, but rather theirs was "a purely rational form of design."[48]

The ideological postulates of rationalism were based on progress and modernity, with a decided commitment to industrial and mechanized production, as well as a rational organization of work. With a tendency towards a progressive and egalitarian political ideology, they wanted to develop a new constructive language that would serve to renew society, which was especially reflected in their interest in urban planning and social housing.[1] Thus, it could be said that the foundations of rationalism are found in the "conciliation between technological progress and social commitment", according to Jeremy Melvin.[49]​.

One of the main premises of the Modern Movement was functionalism "Functionalism (architecture)"), the subordination of architectural language to its function, leaving aside any aesthetic or accessory consideration for the main objective of construction: "form follows function", in the words of Louis Sullivan. Thus, any construction form must reflect the use for which it was designed. According to this theory, even the construction elements - such as beams and pillars - must be left visible, as they are part of the formal design according to which a structure is planned. To achieve this, industrial production and technological advances must contribute, which are tools made available to the architect to optimize their construction work.[50]​.

Within the industrial society and the capitalist economy, the rationalist architect was required to provide maximum functionality and optimization of resources, to develop the best designs with the most economical industrial criteria; He had to consider all the components of life in society, so he had to take responsibility "from the spoon to the city", as they used to say at the time. In general, the majority of rationalist architects had social concerns and considered it a duty of the State to guarantee minimum living conditions (existentzminimum) to the population.[51]​ In rationalism, all the constituent elements of the architectural work were subordinated to function, so function and style are equated.[9]​.

Among the main stylistic features of rationalism are: rectilinear and orthogonal forms, composition in volume rather than mass, uniform and visible structures, absence of axial symmetry, the use of pilotis as a support for the structure, flat roofs, empty central patios, open plan interiors, use of overhangs - especially in balconies and terraces -, facades without ornaments, white walls and rectangular windows, linked in an elongated band and run in the façade plane.[52]​[45]​ Also characteristic is the use—especially in skyscrapers—of the curtain wall (curtain wall), a type of self-supporting glazed façade, independent of the resistant structure of the building, generally built by the repetition of a modulated prefabricated element, which is usually composed of an extruded aluminum frame and a glass panel.[53]​ Another commonly used element is brise soleil, a type of solar protection for windows and balconies, like a blind or lattice, which can be made of various materials, from wood to the concrete commonly used by Le Corbusier.[54]​ It should be noted that rationalist architecture received a certain influence from nautical design, and Le Corbusier even added numerous photographs of ships and ocean liners in his book Vers une Architecture (1923).[55]​.

The main aesthetic factor of the new style was the absence of applied decoration, conceived as a way of eliminating superficiality. The new premise was simplicity, based mainly on industrial materials, a structural order based on regularity versus angularity and on a harmony based on proportion and geometry, and on a design centered on a skeleton of columns (concrete or metal pillars) instead of a mass structure, with a smooth and seamless surface, of smooth materials - preferably metal and glass -, with windows that did not interrupt the perfection of the façade, if possible with light metal frames, and a chromaticism focused on the natural color of the material. They also considered relevant the choice of the place to build and its relationship with the environment, within which the external walls of the building - such as terraces and pergolas - are considered extensions of it, as are the walls and paths of the gardens, whose rectilinear planimetry contrasted with the work of nature. On the other hand, within the ornamental aspect, they considered the inclusion of paintings and sculptures in the building as independent elements that should not degenerate into simple decoration, but should beautify autonomously. In that sense, Hitchcock and Johnson pointed out abstract wall paintings as the ideal complement to modern architecture.[56]​.

Rationalist architecture - especially design - maintained close contacts and influences with the rest of the arts, especially painting, and within this that of avant-garde movements such as neoplasticism, suprematism and constructivism "Constructivism (art)"), all of them with an abstract tendency, from which they took some of their designs and the preference for primary colors, as well as experimentation with various materials and a design based on basic and proportionate shapes. Some of the painters who most influenced the movement were professors at the Bauhaus or maintained contacts with this institution, such as El Lissitzky, Theo van Doesburg, Vasili Kandinsky, Paul Klee, Johannes Itten and László Moholy-Nagy.[57]​.

Rationalism was nourished by an extensive theoretical corpus prepared by some of its most prominent representatives, such as Gropius and Le Corbusier. In 1925, Gropius published Internationale Architektur, where he related his work to that of other architects such as Le Corbusier, Oud and Wright, and pointed out that they all shared a functional vision of architecture, with a logical conception of the work and economic planning to optimize money, materials, time and space. He also noted that "the uniformity of the appearance of modern buildings, arising from global travel and technology, overcomes the natural borders that continue to isolate individuals and peoples, creating a bridge between all cultural regions."[58]​.

Le Corbusier published several books on art and architecture, such as Vers une Architecture (1923), L'Art Décoratif d'Aujourd'hui (1926) and Urbanisme (1925), in addition to publishing with Amédée Ozenfant the magazine L'Esprit Nouveau (1920-1925).[59]​ In his 1923 book he presented his theoretical principles in a series of texts with a somewhat provocative tone, with the aim of opening "eyes that do not see" towards modern architecture. It uses a concise style, with short and simple sentences, to establish clear premises that serve as a guide for the architect, with poetic similes and abundant graphic material. The content focuses on the aesthetic reform of architecture produced since the middle of the century, as well as concepts such as functionalism and industrial design; It speaks of the hygienic and moral qualities of architecture, which symbolizes on an ocean liner: "a pure, clean, clear, neat and healthy architecture." However, he believes that the styles are "a lie", although he recognizes the artistic nature of architecture, since beyond the simple rational function the architect configures an aesthetic to the building. Regarding his treatise on urban planning, he analyzes it from a functional perspective, in which the city is a work tool, and defends general lines based on order and linearity, which will be specified in the Charter of Athens (1943).[60]​.

Critics and art historians such as Henry-Russell Hitchcock, Siegfried Giedion and Nikolaus Pevsner also made their contribution to the theoretical corpus of the movement. Hitchcock made his first contribution to the International Style in an article in the magazine Hound and Horn in 1928, which was followed by the book Modern Architecture, Romanticism and Reintegration (1929), where he stated that the new style was "a distinct branch of modern architecture influenced by cubist and neoplasticist painting." But his most relevant work was The International Style: Architecture since 1922, prepared with Philip Johnson for the 1932 MoMA exhibition.[61]​ In it they established the defining parameters of the movement, noting that:.

The book about the exhibition contains a short text and abundant illustrations. It was written entirely by Hitchcock, as Johnson's participation consisted only of its correction. His thesis focuses on the confirmation of a new contemporary architectural style at the date of the exhibition, with Gropius, Oud, Le Corbusier, Mies van der Rohe, Rietveld and Mendelsohn as main representatives. He establishes the beginnings of this style after the First World War and points out as antecedents architects such as Peter Behrens, Otto Wagner, Auguste Perret and Frank Lloyd Wright, whom he describes as "semi-modern".[63]

Giedion presented his ideas preferably in Space, Time and Architecture. The Growth of a New Tradition (1941), which marked the historical image of modern architecture in Europe and the United States. It is a compendium of the classes Charles Eliot Norton Lectures that he gave at Harvard University between 1938 and 1939. Giedion's main objective was to integrate modern architecture into the history of art, as well as to establish its theoretical bases in a scientific context. He pointed out modern art and architecture as interdependent units and considered the contrast between science and art to be overcome. Just as Hitchcock established the aesthetic principles of rationalism, Giedion also sought to establish its structural principles, analyzing the formal qualities of the movement to find the underlying ideas. It marks the birth of modern architecture in industrialization and advances in engineering, and as pioneers Victor Horta, Hendrik Petrus Berlage, Otto Wagner, Auguste Perret and the Chicago School "Chicago School (architecture)"). It recognizes a fundamental role for Frank Lloyd Wright, but reserves the role of "heroes" of modern architecture for Gropius and Le Corbusier—Mies van der Rohe did not mention it until a reissue in 1954. Giedion's work was the basic manual of modern architecture until practically the 1980s and marked the conscience of two generations of architects.[64]​.

Pevsner was a German historian and critic established in the United Kingdom since 1935. In Pioneers of the Modern Movement (1936, later titled The Sources of Modern Architecture and Design), he introduced the term "Modern Movement", which he considered the "appropriate" style for the century, a functional style that responds to the new needs of the masses. Pevsner advocated a strict, anonymous, impersonal internationalism that leaves "less room for self-expression" and adapts to the new "basic social conditions." Throughout his literary production he developed a history of global, social and cultural architecture, unrelated to personalities and focused on the notion of style, with the intention of differentiating "true styles" from "transitory fashions".[65]

Other books on the Modern Movement were: Internationale neue baukunst by Ludwig Hilberseimer (1926), Die Baukunst der neuesten Zeit by Gustav Adolf Platz") (1927), Moderne Architektur und Tradition by Peter Meyer") (1928), Die neue Baukunst in Europa und Amerika by Bruno Taut (1929), Les tendances de l'architecture contemporaine by Myron Malkiel-Jirmounsky") (1930), The New World Architecture by Sheldon Cheney") (1930), La nuova architettura by Fillia") (pseudonym of Luigi Colombo, 1931), Gli elementi dell'architettura razionale by Alberto Sartoris (1932), etc. It is also worth highlighting the magazines that They spread the new style, such as Die Form, Das neue Frankfurt, L'architecture d'aujourd'hui, La Casa bella, Moderne Bauformen, Wasmuth Monatshefte für Baukunst und Städtebau and The Architectural Review.[66]​.

The first critical voices towards the modern Movement emerged from brutalism in the 1950s and developed in the 1960s with the work of historians and critics such as Reyner Banham and Manfredo Tafuri. Banham was a student of Giedion and Pevsner and, for his doctoral thesis, he was invited by the latter to analyze the Modern Movement from where he had left off, from the pioneers who laid the foundations of this style between the end of the century and the beginning of the . Banham carried out this exercise (Theorie and Design in the First Machine Age, 1960), but he did so from a critical, demystifying perspective; Comparing modern theories with practical implementations to check whether they actually fulfilled the espoused premises, it became evident, however, that in most cases the supposed functionalism defended by rationalist architecture was instead translated into a certain formalism. Faced with this, he advocated a "second age" dominated by the machine and mass consumption, and became the main defender of the style inherited from rationalism: brutalism.[67] Tafuri, a disciple of Giulio Carlo Argan and influenced by Marxism, structuralism "Structuralism (philosophy)," semiology and psychoanalysis, conceived architecture as a part of the history of work, of the mechanisms of production. In Teorie e storia dell'architettura (1968) he criticizes the optimism of avant-garde architecture and offers a more pessimistic vision, in which architecture is an ambiguous and changing process, "a perpetual contestation of the present." Also in Progetto e utopia (1973) he again criticizes modern architecture and points out the need to "destroy the powerful and ineffective myths that still fascinate architects."[68]​.

The architecture of the beginning of the century was born with a disruptive desire with respect to the past, especially in opposition to the historicism that had been practiced since the middle of the century, an academic style based on classical premises and the reinterpretation of styles from the past: neo-Romanesque, neo-Gothic, neo-baroque, etc. A first influence of the new movement was that of modernism "Modernism (art)") —known as art nouveau in France, Modern Style in the United Kingdom, Jugendstil in Germany or Sezession in Austria—, a style that sought to renew the architectural language and that provided some of the initial premises of the Modern Movement, although its excessive decorativeness was rejected by the rationalists. The artistic avant-gardes prior to the First World War, such as expressionism and futurism, were nourished by this style, movements that have sometimes been described as pre-rationalism. After the world war ended and until the mid-1920s, movements such as neoplasticism (De Stijl), the expressionism of the New Objectivity or constructivism "Constructivism (art)") evolved from those initial premises towards a greater formalism that already pointed to the International Style, which was forged in the Bauhaus School and in the founding in 1928 of the CIAM (International Congress of Modern Architecture).[69]​.

It is worth noting firstly as an immediate antecedent of rationalism the new architecture practiced in the century based on the technological advances brought about by the Industrial Revolution, which were reflected in various typologies such as architecture in iron or glass and iron. It should be taken into account that the new industrial era brought with it new problems and approaches in the construction and urban planning fields, since technical, economic and social progress led to the appearance of new needs such as railway stations, bridges and viaducts for new means of transport, changes in cities due to demographic increases that demanded new infrastructures and a whole series of new needs that architecture and engineering had to address.[70] These needs led to a faster and more efficient type of construction. cheap, with more daring solutions and far from academic architecture. A good example were the cast iron constructions, developed by architects and engineers such as Hector Horeau, Henri Labrouste, William Fairbairn") and James Bogardus. A driving factor of this new type of architecture were the trade fairs known as Universal Exhibitions, which due to their ephemeral nature promoted a type of construction of modular forms using prefabricated elements. The first, the Great Exhibition of London of 1851, stood out for the building The Crystal Palace, by Joseph Paxton, made of glass with a metal structure. The paradigm of this type of construction was the Eiffel Tower, built by the engineer Gustave Eiffel for the Paris World's Fair "Exposition Universelle de Paris (1889)") in 1889.[71]​.

Throughout the century, a new way of conceiving design and construction was developed, based strictly on reason and scientific criteria, which subordinated the form of the building to its function: functionalism "Functionalism (architecture)"), also called "architectural or structural rationalism." For this new generation of architects, their main tool was applied mathematics and their fundamental objective was the calculation of the lines of force in the structure of a building. Among its main representatives are: Jean-Nicolas-Louis Durand, Henri Labrouste, Gottfried Semper, Augustus Pugin, Eugène-Emmanuel Viollet-le-Duc, Anatole de Baudot and Hendrik Petrus Berlage.[72]​.

Another influence on modern architecture was that of William Morris and the Arts & Crafts movement, which emerged in the United Kingdom around 1860 and lasted until 1910. This movement defended a revaluation of artisanal work and advocated a return to traditional forms of manufacturing; It stipulated that art should be as useful as it is beautiful, with an ideal of beauty based on purity and simplicity. The greatest architectural exponent of this movement was the Red House, Morris's own house, built in 1859 by Philip Webb in Bexley Heath (Kent), made of red brick with a fluid design, without prominent facades, using traditional techniques; Morris designed the garden and the decoration was carried out by Morris, Webb and the Pre-Raphaelite artists Dante Gabriel Rossetti and Edward Burne-Jones, in a set that was cataloged as a "complete work of art." Other architects of this movement such as Charles Rennie Mackintosh, Arthur Heygate Mackmurdo and Charles Francis Annesley Voysey have just laid down its programmatic foundations: design subject to function, prevalence of vernacular styles and native materials, freedom of style and integration of the building into the landscape.[73]​.

Another of the precedents of rationalism was the so-called Chicago School "Chicago School (architecture)"), developed in the American city of Chicago between 1875 and 1900, and which stood out for being the promoter of a new type of building: the skyscraper. At that time, the city was growing at a dizzying pace thanks to its thriving economy, so construction had to be fast, which is why architects adopted iron engineering techniques. On the other hand, the speculative process of buildable land forced people to build in height to make the investment profitable—a fact brought about by the invention of the elevator in 1853. Thus, a series of large functional style buildings appeared built by architects such as William Le Baron Jenney, Daniel Burnham, John Wellborn Root, William Holabird, Martin Roche, Dankmar Adler and Louis Sullivan.[74] The latter coined the famous phrase "form follows function", the main aphorism of functionalism.[75]​.

The Austrian Sezession, the local variant of modernism, also initiated a path towards rationalism—especially Germanic rationalism. Although international modernism was a renewing movement and opposed to academic historicism, which supported comprehensive design and the use of new materials and technologies, its excessive decorativeness distanced it from the postulates of rationalism; However, the Austrian variant - like the Scottish one represented by the Glasgow School - had a more geometric and rectilinear component that did influence the appearance of Germanic rationalism.[76] Its first exponent was Otto Wagner, a professor at the Vienna Academy who instilled in his students modernity as a starting point for artistic creation, and who was interested in the use of new materials and urban planning approaches in line with new times, such as It can be seen in his renovation of Vienna's Karlsplatz or his metropolitan project with overpasses and stations of modern design. Joseph Maria Olbrich (Sezession building in Vienna, 1898) and Josef Hoffmann (Stoclet Palace in Brussels, 1905-1911) followed in their footsteps.[77] In 1903, Hoffmann and Koloman Moser founded the Wiener Werkstätte (Viennese Workshops), an association close to the Arts & Crafts movement that aimed to bring industry closer to the world of art. applied arts.[78]​.

In the field of urban planning, the theories of Ebenezer Howard and his idea of ​​a garden city were essential for the rationalist proposals, a type of urban entity of residential areas separated by large green areas and connected by large radial avenues, with a nerve center that would bring together buildings for administration, finance, services, education, health, culture and other sectors.[79]​.

Finally, it is worth remembering the work of several architects who, in reaction to the excessive decorativeness of art nouveau, developed in the first decade of the century a more sober style based on classical forms but without falling into the ossified language of academic neoclassicism, but with modern solutions that largely pointed to rationalism. This style is sometimes defined as "modern classicism" or "primitive rationalism" and its greatest representatives were: Tony Garnier "Tony Garnier (architect)"), Auguste Perret, Adolf Loos and Peter Behrens.[80] The first was an architect and urban planner, the first to propose a global model of an industrial city (Une Cité Industrielle, 1917) in which life and technology are combined, with a deep study of the functions urban areas and the adaptation of each element to its function. Most of his works are in Lyon: market and slaughterhouse (1908-1924), Grange Blanche Hospital (1911-1927), Municipal Stadium (1913-1918), United States neighborhood (1920-1935). Franklin in Paris (1903), Ponthieu Street garage (1905), Notre-Dame church in Le Raincy (1922-1923).[81] Loos was initially influenced by Otto Wagner's secessionism, but he distanced himself from it due to his fear of being constrained in a style of marked guidelines and excessive originality, in search of greater simplicity away from any ornamentation. He took from the Arts & Crafts movement his commitment to craftsmanship and a more human component in the construction process.[82]​ Among his works, the following stand out: the residential building on Michaelerplatz in Vienna (1909-1911) and the Steiner (1910) and Scheu (1912) houses, also in Vienna.[83]​ Behrens opted for an architecture of simple, austere and functional lines, with the use of new materials and technologies, with some influence of William Morris. Director of the General Electricity Company AEG of Berlin, he built a series of factories and buildings for it where he anticipated numerous of the structural solutions of rationalism, among which the turbine hall (1909) stands out.[82]​.

Expressionism

Expressionism was a cultural movement that emerged in Germany at the beginning of the century, which was reflected in a large number of fields: plastic arts, architecture, literature, music, cinema, theater, dance, photography, etc. Expressionist architecture developed mainly in Germany, the Netherlands, Austria, Czechoslovakia and Denmark. It was characterized by the use of new materials, sometimes provoked by the use of biomorphic forms or by the expansion of possibilities offered by the mass manufacturing of construction materials such as brick, steel or glass. Many expressionist architects fought in the First World War and their experience, combined with the political and social changes resulting from the German Revolution of 1918, led to utopian perspectives and a romantic socialist program. Strongly experimental in nature, the expressionists' works stand out for their monumentality, the use of brick and subjective composition, which gives their works a certain air of eccentricity. The main expressionist architects were: Bruno Taut, Walter Gropius, Erich Mendelsohn, Hans Poelzig, Hermann Finsterlin, Fritz Höger and Hans Scharoun.[84]​.

Expressionist architecture developed in Germany in various groups, such as Deutscher Werkbund, Arbeitsrat für Kunst, Novembergruppe and Der Ring; The Amsterdam School is also worth highlighting in the Netherlands. The Deutscher Werkbund (German Labor Federation) was founded in Munich in 1907 by Hermann Muthesius, Friedrich Naumann and Karl Schmidt, and later incorporated figures such as Walter Gropius, Bruno Taut, Hans Poelzig, Theodor Fischer, Wilhelm Kreis, Richard Riemerschmid and Bruno Paul. Heir to Jugendstil and Sezession, and inspired by the Arts and Crafts movement, its objective was the integration of architecture, industry and crafts through professional work, education and advertising, as well as introducing architectural design into modernity and giving it an industrial character. The main characteristics of the movement were the use of new materials such as glass and steel, the importance of industrial design and decorative functionalism.[85] This group was the one that organized an exhibition in Stuttgart in 1927 for which they built a large housing colony, the Weißenhofsiedlung, with a design by Mies van der Rohe and buildings built by Gropius, Behrens, Poelzig, Taut and others, together with outside architects. from Germany as J.J.P. Oud, Le Corbusier and Victor Bourgeois. This exhibition was one of the starting points of the new architectural style that was beginning to emerge.[86]​.

Parallel to the German Deutscher Werkbund, between 1915 and 1930 a notable architectural school of an expressionist nature developed in Amsterdam (Netherlands). Influenced by modernism - mainly Henry Van de Velde - and by Hendrik Petrus Berlage, they were inspired by natural forms, with buildings of imaginative design where the use of brick and concrete predominates. Its main members were Michel de Klerk, Piet Kramer and Johan van der Mey, who worked together countless times, contributing greatly to the urban development of Amsterdam, with an organic style inspired by traditional Dutch architecture, in which undulating surfaces stand out.[87]​.

The Arbeitsrat für Kunst (Council of Art Workers) was founded in 1918 in Berlin by the architect Bruno Taut and the critic Adolf Behne. Emerged after the end of the First World War, its objective was the creation of a group of artists who could influence the new German government, with a view to the regeneration of national architecture, with a clear utopian component. Their works stand out for the use of glass and steel, as well as for the imaginative and loaded with intense mysticism. They soon recruited members from the Deutscher Werkbund, such as Walter Gropius, Erich Mendelsohn, Otto Bartning and Ludwig Hilberseimer. After the events of January 1919 related to the Spartacist League, the group renounced its political goals and dedicated itself to organizing exhibitions. Taut resigned as president and was replaced by Gropius, although the group eventually dissolved. 1921.[88] Linked to this was the group Novembergruppe, which emerged in 1918 and was active until 1933, with the aim of using art and architecture to improve the world. Walter Gropius, Hugo Häring, Erich Mendelsohn and Ludwig Mies van der Rohe were among its members.[89]​.

The group Der Ring (The Circle) was founded in Berlin in 1923 by Bruno Taut, Ludwig Mies van der Rohe, Peter Behrens, Erich Mendelsohn, Otto Bartning, Hugo Häring and several other architects, to whom Walter Gropius, Ludwig Hilberseimer, Hans Scharoun, Ernst May, Hans and Wassili Luckhardt, Adolf Meyer "Adolf Meyer (architect)"), Martin Wagner "Martin Wagner (architect)"), etc. Its objective was, as in previous movements, to renew the architecture of its time, with a special emphasis on social and urban aspects, as well as research into new materials and construction techniques. Between 1926 and 1930 they carried out a notable work of construction of social housing in Berlin, with houses that stand out for their use of natural light and their location in green areas, among which the Hufeisensiedlung (Horseshoe Colony, 1925-1930), by Taut and Wagner, stands out. Der Ring disappeared in 1933 after the advent of Nazism.[90]​.

The last phase of German expressionism was the so-called Neue Sachlichkeit (New Objectivity), a mostly pictorial movement that had a translation to architecture based on a rational and objective conception of it, as well as on the social commitment of the architect.[91] This movement took shape in the association Neues Bauen (New Construction), which included Bruno Taut, Erich Mendelsohn and Hans Poelzig.[92]​.

Cubism

Cubism (1907-1914) was an artistic movement based on the deformation of reality through the destruction of the spatial perspective of Renaissance origin and, in its place, the organization of space according to a geometric plot and a simultaneous vision of objects. Although it occurred essentially in the plastic arts, it had some manifestation in the field of architecture, especially in Czechoslovakia.[93] Its main representative was Josef Gočár, who after initially being influenced by the work of Josef Hoffmann, in 1911 joined the Group of Plastic Artists (Skupina Výtvarných Umělců) and began to work in the cubist style, as denoted in the House of the Black Madonna in Prague (1911–1912) and the thermal establishment of Lázně Bohdaneč (1912-1913), where he combined classical and modern forms with pyramidal cubism. After the First World War and the independence of Czechoslovakia, he began with Pavel Janák the search for a Czech national architectural style, which was reflected in the so-called "rondocubism", which incorporates rounded and multicolored shapes from vernacular Bohemian-Moravian decoration, as evidenced by his Legion Bench in Prague (1921-1922). Since 1923 his style evolved towards a functionalism of neoplasticist influence.[94]​.

Other representatives were: Pavel Janák (Jakubec villa in Jičín, 1911-1912; Drechsel villa in Pelhřimov, 1912-1913; Pardubice crematorium, 1921-1923; Adria palace in Prague, 1922-1925);[95] Josef Chochol (Kovařovic villa in Prague, 1912-1913; Bayer and Hodek residential buildings in Prague, 1913-1914);

Futurism

Futurism (1909-1930) was an Italian artistic movement that exalted the values ​​of the technical and industrial progress of the century, which highlighted aspects of reality such as movement, speed and simultaneity of action. Although it occurred especially in the plastic arts, it also had some approach in architecture, although the utopian nature of its formulations prevented its material realization in many cases. The figure of Antonio Sant'Elia stood out, who in 1914 presented his model of a futuristic city, characterized by tall skyscrapers, streets at different levels and new typologies of buildings, such as stations and power plants. In 1914 he signed the Manifesto of Futurist Architecture, where he proclaimed that architecture "must be preserved as art, that is, as synthesis, as expression."[99] Sant'Elia was joined by the architect Mario Chiattone and together they exhibited drawings of their dreamed city of the future, the Città nuova (new city). Died in 1916, Sant'Elia was unable to carry out his projects, but his theoretical work influenced the construction of Giacomo Mattè-Trucco's FIAT workshops in Turin (1915-1921), with flat concrete roofs where cars ran on top of the workshops.[100]​.

Neoplasticism (De Stijl)

Neoplasticism (1917-1932), also known by the Dutch name De Stijl ("the style"), was also an interdisciplinary movement that stood out in painting with figures such as Piet Mondrian and Theo van Doesburg, in an abstract style, while in architecture a style was developed marked by geometric compositions and objective and innovative solutions, with great influence from the work of Hendrik Petrus Berlage. They are works that stand out for smooth surfaces and decomposition into planes, vertical and horizontal lines, with the use of color as an emphasizing element of the structure, generally primary and flat colors.[101] Some of their stylistic hallmarks, such as flat ceilings, smooth walls and free and flexible interior spaces were later characteristic of the International Style.[102]​.

The most paradigmatic work of this style was the Rietveld Schröder House in Utrecht (1924), by Gerrit Rietveld and Truus Schröder, whose structural solutions largely pointed out the main characteristics of the International Style: asymmetrical composition, geometric shapes without relief, flat roofs with overhangs in the corners, absence of ornamentation, longitudinal windows and preference for the color white. This new way of understanding architecture translated into transparent volumes, without load-bearing walls or monumental openings, which gave the buildings an appearance of spaciousness and incorporeality that would be the most attractive image of rationalism.[103] Within a three-dimensional grid, the volumetric composition is based on translations and superpositions of planes, with a fluid sequence of spaces that favors the multiplicity of functions.[104]​.

A variant of neoplasticism was elementarism, a movement founded in 1924 by Theo van Doesburg. In contrast to the primary colors and right angles favored by De Stijl, Van Doesburg introduced greater dynamism through diagonals and rotations, described by this artist as "countercompositions", which marked his break with Piet Mondrian. Although it began in painting, this style was also transferred to architecture, in which the constructivist and Bauhausian influence was noted. Van Doesburg aimed to make a synthesis between the arts and facilitate a practical application of artistic creation in everyday life. In 1924, Van Doesburg and Cornelis van Eesteren published Towards a collective construction, where they declared that "painting, without architectural construction, has no reason to exist." They developed their aesthetics in the Manifesto of Elementarism (1926), in which they defended the contrast of the diagonal in paintings and sculptures with the vertical-horizontal linearity of architecture, as they put into practice in the decoration of the Café L'Aubette in Strasbourg (1928-1929), carried out by Van Doesburg in collaboration with Hans Arp and Sophie Taeuber-Arp.[105]​.

Constructivism

Constructivism "Constructivism (art)") (1914-1930) was a movement that emerged in revolutionary Russia, a politically committed style that sought through art to carry out a transformation of society through a reflection on pure artistic forms conceived from aspects such as space and time, which generated in the plastic arts a series of works in an abstract style, with a tendency towards geometrization. In its architectural aspect, it began a program linked to the revolution that sought a functional architecture that satisfied the real needs of the population.[106]​ Constructivism coincided with neoplasticism in the search for an art of collective utility based on objective aesthetic principles.[107]​ The end of the movement occurred in 1932 with the suppression of artistic groups carried out by the Stalinist dictatorship.[108]​.

Halfway between architecture and sculpture is the Monument to the Third International by Vladimir Tatlin (1919-1920), of which he only made the model. It would have consisted of a structure 395 meters high, with a stepped spiral shape that symbolized the progress of socialism, with floors that would rotate at different time intervals: daily, monthly and yearly.[109] According to Tatlin, the monument represented the "union of purely artistic forms (painting, sculpture and architecture) for a utilitarian purpose."[110]

Like this one, many other projects of the time were not carried out due to the precariousness of the country's political situation, such as the largely utopian postulates of El Lissitzky, which brought together some of the premises of constructivism, neoplasticism and the Bauhaus. Among them are his Proun spaces, which anticipated the environments of the later installation art "Installation (art)"), or his "cloudstand" buildings (1925), horizontal skyscrapers supported by large tower-shaped pillars.[111]​.

The most practical achievements were carried out by two associations: the ASNOVA (Association of New Architects), created in 1923 under the premise of finding universal solutions for architecture, detached from the relationships between form-function or form-social context, and represented fundamentally by Konstantin Melnikov, author of the Moscow Workers' Club (1925-1927) and the Russian pavilion at the Paris Exhibition of Decorative Arts in 1925, and by Nikolai Ladovski, author of the Lenin Institute in Moscow (1927); and the OSA (Union of Contemporary Architects), founded in 1925 with the aim of combining artistic and political avant-garde and creating a productive and utilitarian art, represented by the brothers Aleksandr, Leonid and Víktor Vesnín (Moscow Labor Palace, Pravda building in Leningrad, Lenin Institute in Moscow) and by Iván Nikolayev.[112] It is also worth highlighting the promotion of Russian constructivism the work of Vkhutemás (acronym for Higher Education Workshops in Art and Technology), a state art and technical school located in Moscow that promoted the avant-garde in art and architecture.[113]​.

Organicism: Frank Lloyd Wright

Frank Lloyd Wright was an American architect, a precursor of organic architecture and initiator of the Prairie School movement. In his work, certain coincidences with rationalism are perceived, such as the use of terraces and perpendicular forms, but from an organicist approach, that is, adapted to nature: architectural forms merge with natural ones in an integrated and harmonious whole, as in his famous Kaufmann house, better known as Casa de la Cascade (in English Fallingwater, 1936-1939).[115]

Wright initially worked in Louis Sullivan's studio for six years and inherited from his teacher the idea that American architecture should be renewed. Even so, he thought that the basis of this renewal was in the traditional American way of life and in the integration of man with nature achieved by the pioneers of the American West. Thus, Wright's construction ideal was the single-family house with horizontal spaces, large ceilings and a perfect interrelation with the environment, as in the Waterfall House, which is part of the surrounding landscape. He thus created the typology of prairie houses, of which he built quite a few for businessmen and magnates, as well as his own residence, Taliesin West, in Scottsdale "Scottsdale (Arizona)"), Arizona (1938).[116]

For Wright, architecture had to encompass both the construction itself and its adaptation to its environment; in his words: "an architecture that develops from the inside out, in harmony with the conditions of its being", as well as that "in organic architecture, then, it is totally impossible to have the building as one thing, its furniture as another, and its position and its environment as another."[117] Wright adopted the idea of ​​"total design" from the English Arts & Crafts movement, so in his works he designed both the exterior and the interior of the houses, with a type of furniture that was equally organic in conception. Other notable Prairie School architects were William Gray Purcell and George Grant Elmslie.[118]

The Bauhaus

The Bauhaus School is usually considered the first exponent of a fully mature rationalism. The Staatliche Bauhaus (State Building House) was born in 1919, when the architect Walter Gropius assumed the direction of the Weimar School of Arts and Crafts, which he reoriented towards a multidisciplinary study program that addressed both architecture and design and the decorative arts: the school's students learned theories of form and design, as well as workshops in stone, wood, metal, clay, glass, weaving and painting. The Bauhaus moved to Dessau in 1925 and to Berlin in 1932. Gropius was succeeded by Hannes Meyer in 1928, and he was succeeded by Ludwig Mies van der Rohe in 1930. The school was closed by the center's management in 1933 due to the systematic harassment to which they were subjected by the Nazi authorities.[119]​.

The Bauhaus teaching program was based on the correlation between all creative processes, with the aim of unifying art and design. According to Gropius, "the ultimate goal of the Bauhaus is the collective work of art, in which there are no barriers between the structural arts and the decorative arts." Thus, architects, artists and craftsmen would work together in the construction of the "building of the future."[120] At first the Bauhaus was influenced by the Viennese Sezession and the Wiener Werkstätte, as well as William Morris and the Arts & Crafts movement, by Peter Behrens and Henry Van de Velde, in addition to the expressionism that was fashionable in Germany at the time. However, since 1922 the influence of the Dutch group De Stijl was noticeable and the school became more austere and functionalist, and more focused on industrial design.[120] Again according to Gropius, "we want an architecture adapted to our world of machines, radios and cars with fast engines, an architecture whose function is clearly identifiable by the relationship of its forms."[121]​.

Four phases are distinguished in the history of this school: the first (1919-1924) corresponds to its stay in Weimar and the architectural formulations proposed are still the survival of the expressionist style, with a certain utopian component; With hardly any material achievements, the most relevant project outlined at this stage is Gropius's project for the headquarters of the Chicago Tribune (1922, not carried out), as well as that of an International Philosophical Center in Erlangen (1923-1924), also not carried out. The second stage (1925-1930) began with the move to Dessau, where the school headquarters building was built, the work of Gropius. The school's line is already fully rationalist, with a clear commitment to design and industrial production. The main architectural characteristics of these years are the geometric planimetries, the orthogonal layout, the use of glass curtain walls and horizontal windows, as seen in the projects for "large-scale construction houses" (1924), the teachers' housing (1925-1926) or the Törten Colony in Dessau (1926). During the direction of Hannes Meyer (1928-1930) there was a greater connection with the political left and there was a commitment to an architecture that served the needs of the population, more practical and far from pure forms, which denotes the influence of Russian constructivism. Meyer's main works were the project for the palace of the League of Nations in Geneva (1926-1927) and the School of Trade Unions in Berlin (1928-1930). After Mies van der Rohe (1930-1933) took over the leadership, the school moved towards a conception of architecture more focused on structural issues, with some influence from the Dutch group De Stijl and the Russian architect and artist El Lissitzky. Among Mies' works in these years, the following stand out: the German Pavilion "German Pavilion (Barcelona)") for the Barcelona International Exhibition (1929) "Barcelona International Exhibition (1929)"), the Tugendhat house in Brno (1930) and the Lemcke house in Berlin (1932).[122]​.

In 1923, the Bauhaus organized an exhibition entitled Art and technology: a new unit, in which the Experimental House or Haus am Horn, by Georg Muche and Adolf Meyer "Adolf Meyer (architect)") was presented, a prototype of a functional housing mass-produced and built in steel and concrete, completely decorated with objects and furniture designed by Marcel Breuer.[123] In 1927 the architecture department was established, until then non-existent despite to the school's multidisciplinary approach, led by Hannes Meyer and, in 1928, an urban planning department, led by Ludwig Hilberseimer.[124]

Probably the most notable architectural achievement of this school is the Bauhaus building in Dessau, designed by Gropius in 1925. He created it with strict criteria of functionality, which is why it became an icon of rationalist architecture. The building was made up of two bodies, one rectangular with classrooms and laboratories and another L-shaped with an auditorium, stage, kitchen and dining room, five stories high that housed rooms for students, bathrooms and a gym. Both buildings were connected by a two-story high skybridge, which housed the administration offices. He mainly used concrete and glass as materials, with extensive use of the curtain wall.[125]​.

France

As seen in the background, the pioneers of pre-rationalism in France were Tony Garnier and Auguste Perret. The general lines of later French rationalism were based on most of the premises of the International Style, although with less interest in functionality than in German rationalism. Corbusier, Gropius, Victor Bourgeois and Willem Marinus Dudok; in 1932, André Lurçat and Alberto Sartoris. This association promoted various exhibitions and, in 1934, published the manifesto Pour l'art moderne, cadre de la vie contemporaine, which defended modern architecture. by André Bloc, which served as an organ of dissemination of the new architecture.[127]​.

The main reference of French rationalist architecture was Le Corbusier, pseudonym of Charles-Édouard Jeanneret-Gris. Although Swiss by birth, he settled in Paris in 1917 (at the age of thirty) and became a French citizen in 1930. He was an engraver, designer, painter, sculptor and writer, although, paradoxically, the person who most influenced the architecture of the century did not qualify as an architect.[128] In his beginnings he was influenced by Tony Garnier and Auguste Perret, as evidenced by his use of reinforced concrete. Le Corbusier represents a classicist rationalism, which has its roots in Greco-Roman architecture; According to him, his only teacher had been History. For him, «architecture is the wise, correct and magnificent play of volumes assembled under light. Cubes, cones, spheres, cylinders or pyramids are the large primary shapes that light reveals well. It is the essential condition of the plastic arts."[129]​.

Among his first formulations is the Maison Domino (1914), a typical house designed as an elementary housing cell to be produced in series and allowing the layout of free floor plans, formed by a concrete structure supported on six uprights of cantilever beams. It would serve as a minimum cell to build blocks of flats that he would call immeuble-villas ("city-buildings"), as materialized in his villa Besnus de Vaucresson in 1922.[131]​.

In its beginnings it was linked to purism, a variant of synthetic cubism "Cubism") led together with Jeanneret by Amédée Ozenfant. They admired the beauty and purity of machines, which was their main inspiration along with mathematics, with the desire to integrate architecture, painting and design, concepts that they developed in the magazine L'Esprit Nouveau (1920-1925) and in the book Vers une architecture (1923), as well as in the L'Esprit Nouveau pavilion for the Paris Decorative Arts Exhibition of 1925. In In 1922 he partnered with his cousin, the engineer Pierre Jeanneret, with whom he opened a studio in Paris and, from 1927, he collaborated with Charlotte Perriand on furniture design.[132]​.

Just as Mies van der Rohe preferentially used steel and glass and Le Corbusier used reinforced concrete, both nevertheless achieved free and open structural solutions, which would be the main stylistic hallmark of their work. Another of its characteristics would be the use of , concrete pillars that allowed the building to be supported on an empty space, which accentuated the sensation of volume as opposed to mass.[133] In 1926 he published his , in which he recounted his main architectural proposals: the ground floor on , the open floor, the free façade, the longitudinal window (). and the terrace-garden.[134] Another of his approaches was the ("architectural promenade"), the sequential relationship of spaces between the interior and exterior of a building, which he developed for the first time in the Jeanneret and La Roche villas in Paris (1923).[135] He applied all these principles in the Stein villa in Garches (1927) and, especially, in the Savoye villa in Poissy (1928-1930), one of the most successful examples of rationalist architecture, formed by a square-shaped floor raised from the ground by a series of , with an open plan, elongated horizontal windows and a flat roof on which a terrace-garden is located; It has no façade, no front or back, but is a complex that cannot be grasped from a single point of view.[136] In 1927 he built a version of his Maison Citrohan for the Weißenhofsiedlung in Stuttgart, for which he also built another double-dwelling building.[137] In these years he also developed the unrealized projects for the palace of the League of Nations in Geneva (1927), the World Museum for the Mundaneum in Geneva (1929) and the Palace of the Soviets in Moscow (1931).[136] Between 1929 and 1933 he built the Cité de Refuge in Paris for the Salvation Army, a building inspired by nautical design, and between 1931 and 1933, the Swiss Pavilion for the International University City of Paris.[138]

Germany

In Germany, as has been seen, rationalist architecture was closely linked in its beginnings to expressionism and the various group manifestations that emerged within it, such as Deutscher Werkbund, Arbeitsrat für Kunst and Der Ring, as well as the Bauhaus School, the first in which a fully mature rationalist style was achieved. In the development of German rationalism, it is worth highlighting the Weißenhofsiedlung development, built in Stuttgart in 1927 as an exhibition organized by the Deutscher Werkbund with the aim of promoting low-cost housing, supervised by Ludwig Mies van der Rohe and in which German architects such as Peter Behrens, Richard Döcker, Walter Gropius, Ludwig Hilberseimer, Hans Poelzig, Adolf participated Rading, Hans Scharoun, Adolf Gustav Schneck, Ferdinand Kramer, Bruno Taut and Max Taut, along with others from other countries, such as Victor Bourgeois, Le Corbusier, Pierre Jeanneret, Josef Frank, J.J.P. Oud and Mart Stam. Thirty-one homes were built, designed under premises of visual unity based on white plaster walls, rectangular shapes, flat roofs and horizontal bands of windows.[18]​.

The two main representatives of German rationalism—and world leaders—were Walter Gropius and Ludwig Mies van der Rohe. Gropius was an architect, urban planner and designer, a disciple of Peter Behrens. In his beginnings he was part of the expressionist movement, within which he was linked to the groups Deutscher Werkbund, Arbeitsrat für Kunst and Der Ring. In 1910 he opened his own studio, where he worked in association with Adolf Meyer "Adolf Meyer (architect)"). Among his first works stands out the Fagus Factory (1911-1914), in Alfeld, a rectangular building that stands out for the use of the curtain wall, which would be one of its main stylistic hallmarks. Municipal Theater of Jena.[152]​ In 1919 he founded the Bauhaus School, of which he built its headquarters in Dessau in 1925.[163]​ In 1928 he opened his own office, from which he developed the Dammerstock development in Karlsruhe (1928-1929),[165]​ as well as the Siemensstadt project in Berlin. (1929-1930).[166]​ With the rise to power of the Nazis he was forced to go into exile, first to the United Kingdom and then to the United States, where he was director of the Graduate School of Design at Harvard University (for his American work see here).[167]​.

In 1945 he teamed up with eight young architects in the firm The Architects' Collaborative (TAC). In addition to the works carried out by this studio in the United States, in the 1950s and 1960s he carried out some projects again on German soil: in 1957 he built with Wils Ebert") an apartment block in the Hansaviertel district in West Berlin; shortly after he created the new city of Britz-Buckow-Rudow; and in 1964 he designed the Bauhaus-Archiv building in Berlin, carried out after his death by Alexander Cvijanovic") in 1977.[167]​.

Austria and Switzerland

Austrian rationalist architecture was heir to the Viennese Sezession, through the mediation especially of Josef Hoffmann, a professor at the Kunstgewerbeschule who trained a new generation of architects. After the first post-war period, Hoffmann approached the postulates of rationalism, although with a somewhat more traditional language, as in his popular houses built between 1925 and 1930. In Vienna, a Werkbundsiedlung (exhibition of permanent and temporary buildings promoted by the Österreichischer Werkbund) was held in Vienna in 1932, which promoted a development of experimental housing in the Lainz district, in which thirty-one architects built seventy houses, the “largest exhibition of buildings in Europe” as it was announced at the time. The majority were Austrian architects, among whom Hoffmann himself, Adolf Loos, Walter Loos, Josef Frank, Richard Neutra, Clemens Holzmeister, Margarete Schütte-Lihotzky, Oskar Strnad, Walter Sobotka and Ernst Plischke stood out, as well as the German Hugo Häring, the French André Lurçat and Gabriel Guevrekian and the Dutch Gerrit Rietveld. The result was a set of white houses with an open floor plan and flat roofs, similar to the Weißenhofsiedlung in Stuttgart but somewhat more formalistic.[191] At the housing level, it is also worth highlighting the Karl Marx-Hof in Vienna, designed by Karl Ehn in 1927, a gigantic housing block one kilometer long, rectangular in shape with a large central courtyard that serves as a plaza, garden and community services center, with almost 1,400 apartments.[192]​.

Austrian rationalist architects include: Ernst Plischke, author in 1931 of the Liesing Employment Office in Vienna, considered the "first modern building in Austria"; (1932);[194]​ and Margarete Schütte-Lihotzky, the first woman to qualify as an architect in her country, participating in the construction of the Winarsky-Hof popular house in 1924 and designer of the famous Frankfurt kitchen, as well as equipment for children.[195]​.

Due to its proximity, Switzerland received the direct influence of German rationalism, but also of French rationalism, especially Le Corbusier, Swiss by birth. Although he developed his work in France, Le Corbusier left some samples of his work in his native country: the villas Jeanneret-Perret (1912) and Schwob (1916) in La Chaux-de-Fonds, the villa Le Lac in Corseaux (1923), the Clarté building in Geneva (1930-1932) and the Heidi Weber Museum in Zurich (1963-1967).[196]​.

The initial impulse of rationalism in Switzerland is due to Karl Moser, professor at the Federal Polytechnic School of Zurich who trained a generation of architects among whom were his son Werner Max Moser, the cousins Emil and Alfred Roth, Rudolf Steiger, Max Ernst Haefeli and Carl Hubacher. Many of them later worked in other countries: Werner Moser in the United States with Frank Lloyd Wright, Alfred Roth in Paris with Le Corbusier, Haefeli in Germany with Otto Bartning. In 1930, all of these architects (except Alfred Roth), together with Paul Artaria and Hans Schmidt, were commissioned to build the Neubühl neighborhood in Zurich, another example of popular collective housing like those developed in Germany, with a layout of single-family houses attached in a row.[197]​.

Netherlands and Belgium

Dutch rationalism was a direct heir to the neoplasticism of the De Stijl group. Like the French, he showed less interest in functionalism than the German. Works of notable quality were carried out in this country: according to Leonardo Benevolo, "after the crisis of the German movement, the main contributions to the progress of European modern architecture come from Holland."[209]​.

Jacobus Johannes Pieter Oud was appointed municipal architect of Rotterdam in 1918, a position from which he promoted the construction of low-cost houses in full International Style, most between 1925 and 1930, such as those in Kiefhoek (1925-1927). Those by Hoek van Holland (1924-1927) stand out, a group of white houses arranged in a row, with horizontal windows, metal doors and curved elements of nautical inspiration. In 1927 he built five houses for the Weißenhofsiedlung development in Stuttgart, small in size but with a very practical design and functional furniture. Oud's architecture is largely based on industrial techniques and the use of new materials.[210]​ Among his latest works are the building for Shell in The Hague (1939-1942) and the children's bio-recreation home in Arnhem (1952-1960).[211]​.

Gerrit Rietveld broke with De Stijl in 1928, the year in which he joined CIAM and began a more purely rationalist phase, as can be seen in his houses on Erasmuslaan Street in Utrecht (1930-1931), arranged in a row and rectangular in shape, stuccoed in white and with horizontal windows, in the purest International Style.[212] Other of his works were: the Vreeburg cinema in Utrecht (1936, with Truus Schröder), the Dutch pavilion for the 1954 Venice Biennale and the Van Gogh Museum in Amsterdam (1963-1972, with Joan van Dillen") and Johan van Tricht").[211]​.

Mart Stam was influenced by Mies van der Rohe and El Lissitzky. Two of his first works, the primary schools San Wendel (1924) and Thunn (1925) are already in full International Style. At the Weißenhofsiedlung in Stuttgart in 1927 he built three semi-detached houses forming a rectangular block. He later worked with Ernst May in Frankfurt, where his Budge Nursing Home (1929-1930) stands out, of which Hitchcock and Johnson noted that although it is "guided exclusively by economic and functional considerations, the building also undoubtedly has aesthetic value."[212] He worked with his wife Lotte Beese, a Bauhaus student and collaborator of Ernst May in the Soviet Union - where she met her husband; He was responsible for the neighborhoods of Pendrecht (1948-1952), Het Lage Land and Ommoord (1962-1969) in Rotterdam.[213]​.

Willem Marinus Dudok, an engineer by training, was appointed municipal engineer of Hilversum in 1915, a rapidly growing city of which he was in charge of regulating its general plan and the construction of several popular neighborhoods and public buildings, among which the City Hall (, 1924-1928) stands out.[214] He was also the author of the Dutch pavilion of the University City of Paris (1927), the department store building. De Bijenkorf in Rotterdam (1929) and the Utrecht Theater (1939-1941).[215]​.

United Kingdom and Ireland

Rationalism did not reach the United Kingdom until 1930, due mainly to the rejection of what was considered excessive Germanism in this movement.[228] Many of the rationalist works were built by immigrants from the continent who were escaping the Russian and German dictatorships. Among the British architects, Frederick Etchells stands out), translator into English of Towards a new architecture by Le Corbusier and author of the Crawfords Advertising Building in London (1929); (1929-1930), in Amersham, inspired by Arts & Crafts country houses but built in white concrete with a flat roof and horizontal windows, in the rationalist style; other works by Connell, in association with Basil Ward and Colin Lucas, were the New Farm house in Greyswood (Surrey, 1932), the houses of Parkwood Estate in Ruislip (London, 1935) and Frognal No. 66 in Hampstead "Hampstead (London)") (1938), of Lecorbusierian inspiration.[230]​.

Due to English reluctance towards modern architecture, the majority of constructions were houses for the middle class, but some low-cost homes were also built, such as Kent House in Chalk Fram (London, 1934), by Connell, Ward and Lucas, and Sassoon House in Camberwell (London, 1934), by Maxwell Fry[231]—Fry worked alongside his wife, Jane Drew, with whom he carried out important projects in India and Africa—.[232] Of higher category were the flats on Lawn Road in Hampstead (1933-1934), by Wells Coates, an engineer by profession and English representative at the CIAM through the Modern Architectural Research Group (MARS).[231] Coates was also the author of a country house in North Benfleet, Essex (1934-1936). It is also worth mentioning Francis Yorke, author of the Nast Hyde Villa in Hatfield "Hatfield (Hertfordshire)") (1935), and Owen Williams, author of the Boots pharmaceutical factory in Beeston (1930-1932), which stands out for its profuse use of the curtain wall and its tree-shaped concrete columns.[232]

One of the main exponents of British rationalism was the Russian Berthold Lubetkin, creator of the Tecton company (1932-1948).[note 3]​ One of his main achievements was the Highpoint I building in Highgate, London (1935).[36]​ It is a tall eight-story block in the shape of a double cross, of Lecorbusierian influence, supported on pilotis and surrounded by gardens, with a communal roof-terrace; Le Corbusier himself defined it as "the first vertical garden city of the future."[234] Other works of the Tecton seal were: the Finsbury health center (London, 1939), the houses on Genesta Road (London, 1934), Six Pillars on Crescent Wood Road (London, 1935) and Newton Road (London, 1938).[235] The signature of architects, together with the engineer Ove Arup, he was responsible for the gorilla cage and the penguin pool at the London Zoo (1932-1937), whose innovative design, close to constructivist sculpture, brought them notable success.[234]​.

Nordic countries

In general, the Nordic countries developed a regionalist variant of the International Style, due to the circumstances of their climate and the materials used, where the use of wood stands out.[240] The main exponent of Nordic architecture was the Finnish Alvar Aalto, halfway between rationalism and organicism. Faced with the excessive geometrization of orthodox rationalism, Aalto defended, like Frank Lloyd Wright, integration with nature, as well as the use of natural materials such as wood. While still a student at the Helsinki Polytechnic University he designed his parents' house in Alajärvi. Graduated in 1921, he worked for two years in the project office of the Göteborg Exhibition. In 1924 he married Aino Marsio, with whom he formed a professional couple. His first notable work was the Jyväskylä People's House (1924-1925), inspired by Florentine architecture.[241] Between 1927 and 1929 he built a standardized block of flats in Turku with prefabricated concrete elements reminiscent of the works of Mies and Gropius for the Weißenhofsiedlung. In 1929 he participated in the II CIAM, where his contact with Siegfried Giedion and with artists such as Constantin Brâncuși, Georges Braque and Fernand Léger brought him closer to the avant-garde. Between 1927 and 1929 he built the building for the Turun Sanomat newspaper, based on Le Corbusier's "five points for a new architecture." Another important work from its beginnings was the Viipuri public library (1927-1935), which shows its evolution from a certain classicism towards functionalism.[242]​.

Fame came to him with the Paimio Sanatorium (1929-1933), a work adapted to its natural environment for which he studied in depth the path of the sun to make the most of its impact on the building, so that the sick could enjoy maximum light and heat. In 1931 he settled in Helsinki, where he began to design industrially produced furniture; His foray into wood led him to also use this element in architecture, so his style evolved towards greater organicism. Among his works from these years are his house in Helsinki (1934-1936), a complex of houses for workers and a pulp factory in Sunila") (1935-1939) and the Villa Mairea in Noormarkku (1938-1941), which shows his transition towards an organicism of rural influence, which has been described as a "romantic modern movement".[243] In 1937, a exhibition of his works and, in 1939, he built the Finnish Pavilion for the World's Fair in New York, a building that made Frank Lloyd Wright affirm that Aalto was a genius.[241] His later work leaned towards a more expressive and regional design.[243] In 1952 he married for the second time another colleague, Elissa Mäkiniemi, with whom he designed the municipal center of Seinäjoki, composed of the town hall, a church, a theater, a library and a multidisciplinary room. Since 1960 he worked on the urban reorganization of Helsinki. He carried out works in various countries, such as the Aalborg Art Museum (Denmark) or the Siena Cultural Center (Italy).[241]

Eastern Europe

In the Soviet Union, the end of constructivism and the promotion of socialist realism by Stalinism caused the absence of rationalist proposals in the country since the beginning of the 1930s. This was staged with the competition for the Palace of the Soviets in 1931, which was attended by renowned rationalist architects such as Gropius and Le Corbusier, as well as numerous Russian constructivists, but which was awarded to the academic Boris Iofán. [266] Despite everything, it is worth noting the presence of a building designed by Le Corbusier in Moscow, the Centrosojuz (1928-1936), headquarters of the Central Union of Consumer Cooperatives (currently the State Statistics Committee).[267] However, the end of the Stalinist dictatorship led to the return of rationalism since 1955, thanks to Khrushchev's support for functionalism and industrialization, which led to an architecture that was linked to the International Style in its most productivist aspect, without any type of remembrance of the previous constructivism. From the Modern Movement they adopted centralized planning as a methodology, which they considered appropriate for a socialist system, and which they applied to the growth process of urban structures, with a special interest in collective housing, based on serialization and prefabrication. Public buildings were also designed with a great display of modern materials and technologies.[268] The so-called "Soviet modernism" combined rationalism and a certain monumental character inherited from socialist realism, with a certain influence of English brutalism and the Japanese metabolism. Among the main achievements are: the National Library in Ashgabat, Turkmenistan (1969-1975, by Abdullah Akhmedov"), Boris Shpak") and Vladimir Alekseev"); the Orlov Museum of Paleontology in Moscow (1972-1987), by Yuri Platonov"); the former Ministry of Transport in Tbilisi, Georgia (1977-1979, now Bank of Georgia), by Georgi Chakhava") and Zurab Dzhalaganiya"); the Lenin Museum in Gorky (1975-1987), by Leonid Pavlov; and the Druzhba Sanatorium in Yalta, Ukraine (1986), by Igor Vasilevsky").[269]​.

In Czechoslovakia, born after the First World War, it was influenced by its proximity to German rationalism, of which it also had a direct contribution in its territory: the Tugendhat villa of Ludwig Mies van der Rohe, in Brno. Jiří Kroha Fine Arts Pavilion. It is also worth mentioning the Devětsil group, founded in 1920 by Karel Teige, Jaromír Krejcar and Josef Chochol, who published several magazines on modern architecture, which were however criticized for their excessive concern with form.[270] Two Werkbundsiedlungen were held in Czechoslovakia: in Brno in 1928 (known as Nový Dům, "New House"), in which nine members of the Czechoslovak Werkbund built sixteen single-family houses in the Brno-Žabovřesky district;[271]​ and in Prague in 1932-1933 (Baba neighborhood), which with the general planning of Pavel Janák, various houses designed by eighteen architects, all Czech except the Dutch Mart Stam, were also built.[272]​.

Italy

After the utopian futurist formulations, in the 1920s Italian architecture moved towards rationalism, through several groups that sought to integrate Italian architecture into the international avant-garde: Gruppo 7 and M.I.A.R. The first was founded in 1926 in Milan by seven architects from the Milan Polytechnic: Giuseppe Terragni, Luigi Figini, Guido Frette"), Sebastiano Larco"), Gino Pollini, Carlo Enrico Rava") and Ubaldo Castagnoli") (replaced a few months later by Adalberto Libera). 1927, they opposed both the "vain and destructive fury" of Futurism and the "artificial impetus" of the Novecento "Novecento (art)"), a movement founded in 1922 that sought to renew art without breaking with tradition - hence its name, which was linked to the Quattrocento and the Cinquecento -, with the idea of reinterpreting classical architecture in a modern way but without losing its essence. Faced with this, Gruppo 7 sought to adapt the International Style to the Italian idiosyncrasy, under the premise that "true architecture must evolve from a strict adherence to logic and reason."[297]​.

The group became known at the 1927 Monza Biennale, where they exhibited several industrial-inspired models and designs, which shortly after were shown at the Deutscher Werkbund exhibition in Stuttgart. The first rationalist building was built by Terragni, the main exponent of the group, an apartment block called Novocomum - better known as "the Transatlantic" - located in Como (1927-1928), which denotes the Lecorbusierian influence, as well as constructivism and metaphysical painting, achieving a synthesis of national and international sources. In 1928, a large exhibition was organized in Rome entitled Esposizione dell'Architettura Razionale, in which both Gruppo 7 and other Italian rationalist architects participated and which led to the convergence of all of them into a larger group, giving rise to the M.I.A.R.[298]​.

The M.I.A.R. (Movimento Italiano per l'Architettura Razionale) was founded in 1930. Along with some of the members of Gruppo 7 such as Terragni, Figini, Libera and Pollini, they were joined by architects from all over Italy such as Luciano Baldessari, Giuseppe Pagano") and Mario Ridolfi"). Its premises were based on those of the Milanese group, the adaptation of international currents to Italian architecture, again with the competition of the Novecento, which was favored by the fascist dictatorship of Benito Mussolini, who considered avant-garde artists as "degenerates." To make themselves known, in 1931 they organized the II Esposizione dell'Architettura Razionale in Rome, for which the art critic Pietro Maria Bardi wrote the Manifesto of Rational Architecture and a Report for Mussolini on architecture.[298]​.

The group's main achievement was the Casa del Fascio in Como (1932-1936, current Casa del Popolo), the work of Giuseppe Terragni. Conceived as the headquarters of local fascists, it was made up of a white cube, located around a patio with a glass roof and covered in marble. Other works by Terragni were: the Rustici house (1936-1937), the EUR Congress Building (1938, with Pietro Lingeri") and Cesare Cattaneo), the Casa del Fascio in Lissone (1938-1939, with Antonio Carminati")) and the Giuliani Frigerio house in Como (1939-1940).[299] It is also worth highlighting the residential and industrial projects for the company. Olivetti in Ivrea "Ivrea (Italy)") carried out by Figini and Pollini. Other works by the group were: the Casa Elettrica (1930), by Figini, Pollini and Pietro Bottoni"); and the press pavilion by Luciano Baldessari and the graphic arts center by Giovanni Muzio for the I Milan Triennale in 1933.[300]​ In the late 1930s The group was increasingly persecuted by fascism and by the association, defenders like German Nazism of an anti-modern style, so the group's activities practically ceased, definitively disappearing after Terragni's death in 1941.[301]​

Spain

In Spain, rationalism arrived late, at the end of the 1920s, so its reception came in an established, uncritical way, and its first exponents adopted it in an epidermal, eclectic way, transferring its solutions without considering a possible adaptation to the national environment. One of these first pioneers was Luis Gutiérrez Soto, author of works of notable quality but out of context, such as the Europa (1928) and Barceló (1931) cinemas in Madrid, the Madrid-Barajas airport (1930) and the Bar Chicote in Madrid (1931).[309]​.

In 1928, Le Corbusier gave lectures at the Institución Libre de Enseñanza in Madrid that had a powerful influence on the young architects of that time. Some of them joined together under the acronym GATEPAC (Group of Spanish Architects and Technicians for the Progress of Contemporary Architecture). This group was founded in Zaragoza on October 26, 1930 with three subgroups: Center, located in Madrid, formed by Fernando García Mercadal, Víctor Calvo, Santiago Esteban de la Mora, Manuel Aníbal Álvarez"), Manuel Martínez Chumillas") and Felipe López Delgado; North, located in the Basque Country, which had José Manuel Aizpurúa, Joaquín Labayen and Luis Vallejo; and Este or GATCPAC (Group of Catalan Architects and Technicians for the Progress of Contemporary Architecture) in Catalonia, the most active group, among whose members stood out Josep Lluís Sert, Josep Torres Clavé, Joan Baptista Subirana, Sixte Illescas, Germán Rodríguez Arias, Ricardo de Churruca, Antoni and Ramon Puig i Gairalt, Raimon Duran i Reynals, Jaume Mestres i Fossas and Antoni Bonet Castellana.[50]​ The group's purpose was to "contribute in our country to the development of the new universal orientation in architecture and to solve and study the problems that arise in its adaptation to our environment."[310]​.

The group was a member of the CIAM and, in March 1932, organized a CIRPAC meeting in Barcelona in order to prepare the Moscow CIAM - finally held in Athens in 1933 -, in which Le Corbusier, Victor Bourgeois, Walter Gropius, Sigfried Giedion and Cornelis van Eesteren gave lectures.[311] As a disseminating organ of their activities they published a magazine, A. C. Documents of Contemporary Activity (1931-1937), based on avant-garde magazines such as Das Neue Frankfurt, directed by Ernst May, or L'Esprit Nouveau, by Le Corbusier and Amédée Ozenfant.[312]​ In 1933 the northern and central groups dissolved, leaving only the GATCPAC as an active group until the end of the War Civil.[313]​.

The Central sector had little activity as a group—only the organization of some congresses and a certain participation in the magazine A.C., published in Barcelona—, and showed a certain internal incoherence.[314] Fernando García Mercadal, one of the founders of the CIAM in 1928 and Spanish delegate of CIRPAC, stood out.[315] A member of the so-called generation of '25, his style moved like that of his co-religionists in a rationalism. marked by a certain academic heritage and interpreted modern language in a more formalist than programmatic way. His first project close to rationalism was the pavilion in Zaragoza (1927), which denotes a certain influence of . Later, it is worth mentioning the Museum of Modern Art "Museo de Arte Moderno (Spain)") in Madrid (1933), from which he moved away from the avant-garde.[316]​.

Portugal

The first vestiges of rationalist architecture emerged in the mid-1920s with a certain influence of Le Corbusier, Gropius and Robert Mallet-Stevens, as denoted in works such as the Capitol cinema-theater by Luís Cristino da Silva (1925-1931), the Instituto Superior Técnico by Porfírio Pardal Monteiro (1927-1932) and the Radiology Pavilion by Carlos João Chambers Ramos (1927-1933), all in Lisbon.[343] In addition to the above, it is worth mentioning Cassiano Branco, author of the Hotel Victoria in Lisbon (1934-1936); and Francisco Keil do Amaral, strongly influenced by the Dutchman Dudok (Secil School in Setúbal, 1938-1940; Lisbon airport, 1938-1942).[344]​.

During the beginning of the Salazar dictatorship, a reversal occurred, in which, as in other totalitarian regimes of the time, architecture returned to classicist academicism, with a special reference in the pombaline baroque "Architecture of Portugal") (soft Portuguese style).[345] This began to soften starting in the 1950s, when a new generation of architects took up the modern language. It is worth mentioning Rui Jervis Atouguia, author of the project for the Estacas neighborhood in Lisbon, inspired by the Letter of Athens (1949), the school in the São Miguel neighborhood, where he applies the Lecorbusierian brise-soleil (1949-1955) and the Calouste Gulbenkian Foundation (1959-1969), with Pedro Cid") and Alberto Pessoa;[346]​ Of Pessoa himself, it is worth highlighting the Infante Santo housing complex in Lisbon (1952-1955), blocks suspended on pilotis;[246]​ Jorge Segurado, influenced by Dutch architecture, author of the Mint in Lisbon (1953);[347]​ Fernando Távora, author of the Campo Alegre urban plans (1949) and the Ramalde neighborhood in Porto (1952-1962), inspired by the Letter from Athens, as well as works where he develops a regionalized rationalism in the style of Aalto or Le Corbusier in India (Escuela Primaria do Cedro in Vila Nova de Gaia, 1957-1961; Ofir's house, 1957-1958);[348] Nuno Teotónio Pereira, author with Bartolomeu Costa Cabral") from the Aguas Libres housing complex in Lisbon (1953), one of the largest in the International Style in Portugal; the Lisbon Industries (1957).[344]​.

Greece

Rationalism was introduced little by little in Greece in the 1930s, coexisting with traditional architecture. Among the first works, a villa in Glyfada by Stamos Papadakis" (1933) stands out. During the Second World War several architects left the country and settled in France, where they entered Le Corbusier's workshop, such as Georges Candilis, Iannis Xenakis and Aristomenes Provelengios"). After the war, the country began a vast reconstruction process, although the real estate sector was abandoned to private investment. In the 1950s, several large projects were developed: in 1955 Dimitris Pikionis was commissioned to organize the area surrounding the Acropolis; The following year, Konstantinos Dekavallas") was commissioned to rebuild the island of Santorini, devastated by an earthquake, for which he developed an ambitious project of Lecorbusierian influence; during those years Aris Konstantinidis also developed one of the few state-financed social housing programs, while, as director of the Studies Office of the National Tourism Agency, he was in charge of building numerous hotels, such as those in Kalambaka, Epidaurus and the island of Poros "Poros (Greece)"). In the 1960s, it is worth highlighting the construction of several university complexes in Athens, Thessaloniki, Crete and other places.[351]​.

Leading architects include Dimitris Pikionis, Nikolaos Mitsakis and Patroklos Karantinos. The former trained as an engineer in Athens and completed his studies at the École des Beaux-Arts in Paris. His early works denote the rationalist influence due to their functionality, simplicity and use of the open plan, such as some single-family houses, a school in Aegina, an open-air theater in Athens and a school in Lycabettus. Since 1935 he combined rationalism and popular architecture: Experimental School in Thessaloniki (1935), residential complex of Aixoni, villa and kindergarten of Filotei (1950-1960), mayor's office of Volos (1961). Between 1955 and 1958 he was in charge of the planning of the surroundings of the Acropolis and the Philopagos Hill.[352] Mitsakis studied in Athens and was a strong defender of modern architecture. He worked in the Ministry of Education, where he was in charge of the construction of numerous schools, with a clear Lecorbusierian influence, in which he combined modern technology and traditional materials; The Aristotle girls' school in Athens, the school complex in the Hagia Sophia neighborhood in Thessaloniki, the Dimitsana Lyceum and the schools of Naxos "Naxos (island)") and Tinos stand out. He died in the Second World War.[353] Karantinos graduated from the Athens School of Architecture and completed his training in Paris with Auguste Perret. He was a member of the CIAM, for which he was in charge of organizing the IV Congress in Athens (1933). He participated as coordinator in the school buildings program initiated in 1928 by Eleftherios Venizelos. His works include several buildings for the University of Thessaloniki (1948-1960) and the archaeological museums of Iraklion and Thessaloniki (1960).[283]

United States and Canada

The first exponents of rationalist architecture in the United States came in the 1920s at the hands of immigrant architects, such as the Austrians Rudolf Schindler and Richard Neutra, established in California. Both were influenced by Adolf Loos, Erich Mendelsohn and Frank Lloyd Wright. His first major project was the Schindler-Chase house in West Hollywood (1921-1922), with concrete floors, prefabricated walls, and wooden ceilings and internal partitions. His most famous work is the Lovell Beach House in Newport Beach (1925-1926), with a cantilevered structure of five concrete pillars that elevate the house above the beach and a two-level space that "highlights the unity and continuity of the overall volume of the building's interior," according to Hitchcock and Johnson. Schindler's other works were: the Wolfe House in Avalon "Avalon (California)"), Catalina Island "Santa Catalina Island (California)") (1928-1929), the Rodakiewicz House in Los Angeles (1937), the Hiler House in Hollywood (1944) and the Bethlehem Baptist Church in Los Angeles (1944).[355] Neutra's work differs from rationalism. European in his search for greater luxury and comfort - not in vain were they residences for Hollywood stars - as well as a greater integration of the house into the landscape, with large windows that sought transparency and provided great luminosity.[356] Settled in the United States in 1923, he also worked with Wright in Taliesin (Wisconsin). His best work is the Lovell Health House in Griffith Park, Los Angeles (1927-1929), built for the same client as Schindler's Newport Beach house, Dr. Philip Lovell; This is a nursing home, a full example of internationalism due to its horizontality and its glass and metal structure. Other works by Neutra were the Josef von Sternberg house in Northridge "Northridge (Los Angeles)"), Los Angeles (1936), the Kaufmann house in Palm Springs (1947) and the Tremaine House in Santa Barbara "Santa Barbara (California)") (1947-1948).[357]

When Franklin Roosevelt became president of the country in 1932, he began a broad construction program—within the economic policy of the New Deal—to alleviate the effects of the crash of 1929, which largely included the principles of low-cost housing that had been developed in Europe. Walter Gropius and Marcel Breuer designed a working-class town in New Kensington (Pennsylvania) in 1940, based on prefabricated housing. Gropius collaborated with the General Panel Corporation for the standardization of structural parts, which became a common construction method.[356] The New Deal policy favored the dissemination of a new type of architecture that was more functional and linked to industrial design, in which the influence of designers such as Norman Bel Geddes and Henry Dreyfuss was noted. In this context, American architecture began to distance itself slightly from the rigid European cubic rationalism, with more functional and aerodynamic forms (Streamline moderne), as denoted in the Coca-Cola bottling factory in Los Angeles (1936), by Robert V. Derrah").[358]

Brazil

One of the main Latin American countries where rationalist architecture had an outstanding development was Brazil. The first exponents came in the 1920s at the hands of the Russian émigré Gregori Warchavchik, author of the first rationalist houses in São Paulo, such as his own (1927-1928) and the Casa Moderna (1930).[233] He worked associated with Lúcio Costa, who would be one of the main architects of the International Style in Brazil. The main impulse to the new style came thanks to the 1930 revolution led by Getúlio Vargas, of a progressive type. Culture). Costa had the advice of Le Corbusier, who spent three weeks in the country in 1936 and left his mark on some features of the new building, such as the use of brise-soleil. It is a fourteen-story skyscraper raised on pilotis, with a façade in the form of a grid of vertical screens with adjustable horizontal panels.[394]​.

The style took hold during the 1930s and 1940s, but got a definitive boost with the decision in 1956 by President Juscelino Kubitschek to move the capital to a new city built from scratch: Brasilia (1956-1960). The new city was entrusted to Lúcio Costa in the urban planning field (for its planning see here), while Oscar Niemeyer was in charge of construction.[395]​ Niemeyer adopted the Lecorbusierian language, adapting it to the baroque tradition of the country, which is denoted in his use of curved surfaces.[396]​ The nerve center of the new capital is located in the Plaza de los Tres Poderes, named after the three public powers that are found around the square: the executive, represented by the Palácio do Planalto (presidential headquarters); the legislative, represented by the Nereu Ramos Palace (headquarters of the National Congress); and the judicial, represented by the Supreme Federal Court (1958-1960). Both the Palácio do Planalto and the Supreme Court have a similar design, formed by a glass box with a structural frame of modern but somewhat classicist design. The National Congress presents a greater innovation: it is formed by a low rectangular building that serves as a podium for an elevated plaza accessed by a pedestrian ramp, above which rise two twin blocks in the center and two sculptural forms that crown the chambers of the Assembly (Senate and Deputies), one in the shape of a dome and the other in the shape of a bowl. The shape of the central buildings is reminiscent of the United Nations headquarters, in whose design Niemeyer intervened. His most visually poetic work was the Cathedral of Our Lady Aparecida (1959-1970), with a hyperbolic concrete structure in the shape of a crown of thorns, whose nerves are intertwined with a metal mesh of endothermic polygonal glass, in a combination of white and blue that evoke the sky and the sea; Most of the interior building is underground, while on the surface there is the bell tower, free from the church, in addition to the sculptures of the apostles by Alfredo Ceschiatti. In addition to these buildings, he built the Palácio da Alvorada (1956-1958), the president's residence, a rectangular box with a glass façade and an expressionist colonnade, with a barred interior; the Cláudio Santoro National Theater (1958-1981), shaped like an irregular pyramid; and the Itamaraty Palace, headquarters of the Ministry of Foreign Affairs (1962-1970), made with raw concrete and a design that combines classic and modern forms.[397]​.

Latin America

In Latin America, the hegemonic style until the Second World War was neocolonial, although since the 1930s there were various exponents of rationalist architecture. However, since 1945 there was a new architectural effervescence that had the International Style as a reference, although contextualized to the socioeconomic reality of Latin American countries, with a more monumental and exuberant, structuralist seal and with a desire to integrate all the arts.[402] According to Josep Maria Montaner, «in Latin America there are the most interesting, spontaneous and daring experiences of searching for their own interpretation of the language. rationalist».[403]​.

Among the various Latin American countries, two trends can be observed: one that is more international and prone to the use of advanced technologies, as in Argentina, Chile, Cuba and Venezuela; another of a more national character and more artisanal procedures, with allusions to pre-Columbian architecture - especially in the pictorial, sculptural or ceramic decoration -, as in Mexico, Colombia and Peru.[404] Likewise, two periods should be distinguished: the years 1940 and 1950, marked by a rapid diffusion of rationalism, especially in Mexico and Argentina; and the years 1960 and 1970, in which the movement spread to other Latin American countries, while the crisis of the modern Movement began at the end of this period.[404]​.

It should be noted that Le Corbusier had numerous disciples in Latin America: Jorge Ferrari Hardoy, Juan Kurchan and Conrado Sondereguer") in Argentina; Emilio Duhart, Roberto Matta, Guillermo Jullian and Roberto Dávila Carson") in Chile; Rogelio Salmona and Germán Samper in Colombia; Enrique de la Mora, Teodoro González de León, Enrique Castañeda") and Vicente Medel") in Mexico; Roberto Waceham") in Peru; Carlos Gómez Gavazzo and Justino Sierralta") in Uruguay; and Augusto Tobito Acevedo") in Venezuela.[405]​ In addition to the Lecorbusierian influence, Latin American architecture also shows the influence of other rationalist masters such as Gropius, Mies van der Rohe and Alvar Aalto, as well as the organicist Frank Lloyd Wright.[403]​.

In Argentina, as there was no pre-existing indigenous architecture, the construction models were always of European origin. The first rationalist vestiges date from the late 1930s: in 1938 the Spanish emigrant Antoni Bonet Castellana—former member of GATCPAC—founded, together with Jorge Ferrari Hardoy, Juan Kurchan and other young architects[note 7]​ the Austral Group (1938-1945), with clear Lecorbusierian influence—the three met in Le Corbusier's studio in Paris—which promoted rationalism. with a certain surrealist ascendancy, interest in psychology, concern for the landscape and incorporation of local techniques and materials. Some of his works were: the house located between Paraguay and Suipacha streets in Buenos Aires (1938-1939), the OKS house in Martínez "Martínez (Buenos Aires)") (1954-1958), the Rivadavia tower in Mar del Plata (1956) and the Cristal Plano Pavilion at the Sesquicentennial Fair in Buenos Aires (1960), by Bonet; and the building on Virrey del Pino Street in Buenos Aires (1941-1943), by Ferrari and Kurchan. Another architect of Lecorbusierian influence was Amancio Williams, author of his parents' summer house - known as Casa sobre el Arroyo - in Mar del Plata (1943-1945), a work of great originality in that he built the house on a large vault.[407]​.

Asia

On the Asian continent, rationalism had a notable development in India, especially thanks to the presence of Le Corbusier, who built several buildings in Ahmedabad and Chandigarh between 1951 and 1965. Chandigarh was a newly built city after the division of the Punjab between India and Pakistan, since its previous capital, Lahore, fell into Pakistani territory. The urban planning project was entrusted to Le Corbusier, who had the collaboration of Pierre Jeanneret, Maxwell Fry and Jane Drew (for its layout see here).[435]​ In his buildings, he applied the postulates of his Unité d'Habitation and preferably used raw concrete, a material suitable for the material circumstances of the country.[436]​ Among the government buildings, the Capitol Complex (1951-1962) stood out, composed of three buildings: the Legislative Assembly, the Secretariat Building and the Palace of Justice, as well as a plaza-monument baptized Open Hand ("open hand").[437] For its layout, the Modulor system was used, as well as a construction language based on the repetition of modules at different scales, such as terraces, brise-soleil and the traditional Indian chhatri, a type of parasol. In the Assembly (1951-1962) he designed a rectangular box with a façade with a repetitive pattern and a side entrance composed of a porch of spoiler-shaped pillars that supports a curved roof. The High Court of Justice (1951-1955) is a rectangular box with a cantilevered vaulted shell and a façade composed of a pattern of recessed brise-soleil, while the entrance features three large columns rising to the roof. The Secretariat (1951-1958) is a long and narrow block also composed of repetitive modules with brise-soleil and roof-terrace. Another of the Lecorbusierian buildings in the new city was the Government Museum and Art Gallery.[438]​.

In Ahmedabad, Le Corbusier built two houses: Sarabhai and Shodan, both from 1951-1956. The first features a design of eight juxtaposed barrel vaults, with thick walls and a grass-covered roof to combat the heat. The second consists of a reinforced concrete box with cured slits and a cantilevered roof to act as a parasol, under which a terrace is located, following the precepts of the Maison-Domino. On a larger scale, in the same city he created the building of the Mill homeowners' association (1951-1954), in which he adapted his "five points" to the Indian context, with a promenade architecturale with an open floor plan and Domino structure, a free façade with brise-soleil and a cantilevered pavilion with a terrace-garden; and the Ahmedabad Cultural Center (1951-1958), a complex composed of brick compartments with open spaces and a series of internal courtyards with walls covered with vines.[439]​.

The presence of Le Corbusier promoted rationalist architecture in the country, which had government support, since after the independence of India in 1947 the new authorities were looking for a national style in line with modernity that would show the image of the emerging nation.[440] Indian rationalist architecture followed in the wake of Le Corbusier's final stage, with a more "heroic" tone and marked by the use of raw concrete. The most outstanding disciple of the Swiss architect was Balkrishna Doshi, who worked in his Paris studio between 1950 and 1954. Returning to his country, he was the author of the homes for the Ahmedabad Textile Industries Research Association (1957-1960) and the Ahmedabad School of Architecture (1968). Charles Mark Correa studied at the Massachusetts Institute of Technology and opened his office in Bombay in 1958. He was the author of the administrative building of Anand University (1958-1960), the Ramkrishna House in Ahmedabad (1962-1964) and the Salvation Church in Bombay (1974-1977). Achyut Kanvinde was a student of Gropius at Harvard and, upon returning to his country, he was the author of various Bauhausian-style buildings, among which the Indian Institute of Technology in Kanpur (1959-1966) stands out. Shiv Nath Prasad") remained faithful to Lecorbusierian orthodoxy until the 1970s, as can be seen in his Akbar Hotel in New Delhi (1965-1969). It is also worth highlighting the presence in India of Louis Kahn, author of the Indian Institute of Management in Ahmedabad (1962-1974), a series of brick blocks that combined cubic and cylindrical shapes. Based in India since 1952, the American Joseph Allen Stein was the author of several projects in New Delhi, such as the India International Center (1958-1962) and the Ford Foundation building (1966-1968, with Garrett Eckbo).[441]​.

Africa

The African continent was divided for the most part since the century into colonies administered by European powers, until after the Second World War they gradually became independent from their metropolises. In the French colonies of the Maghreb, in North Africa, the majority of projects were by French architects. Le Corbusier himself developed an urban plan for the city of Algiers in 1932 - called the Obús Plan - which was ultimately not executed due to its utopian approach and local difficulties in its practical implementation. (1938-1942), not executed.[472] Another work by Le Corbusier in the Maghreb was the Baizeau villa in Carthage, Tunisia (1928), adapted to the climatic conditions of the area: it has an anti-sun screen that provides shade and the rooms are interconnected to promote ventilation.[473] A disciple of his, the also Swiss Pierre-André Émery, worked in Algiers from 1925 to 1962, where he led the new generation of modern architects; His works include the working-class mine towns of Ouenza (1948-1953), the schools of Ben-Akhoun (1953) and Châteauneuf (1954), several buildings for Électricité et Gaz d'Algérie and the Protestant temple of Hussein-Dey (1960).[474] Oscar Niemeyer, author of the University of Constantine, also worked in this country. (1968-1970) and the Ministry of Foreign Affairs in Algiers (1974).[211]​.

In Morocco, rationalism had its first vestiges in the 1930s with some architects of Lecorbusierian influence such as Marcel Desmet") and Maurice Sori"), authors of several buildings in Casablanca. In the second post-war period, a generation of young architects (Georges Candilis, Gaston Jaubert, Élie Azagury, Jean-François Zévaco, Jean Chemineau) led the transformation of cities such as Rabat and Casablanca, and formed GAMMA, the local branch of CIAM. and Nids d'abeille) by Georges Candilis, Shadrach Woods and Vladimir Bodiansky (1951-1956), based on the Lecorbusierian Unité of vertical blocks with brise-soleil balconies and garden terraces, combined with lower buildings. André Lurçat also built a housing estate in Casablanca (1953-1955), inspired by his Hotel Nord-Sud in Corsica.[476]​.

In West Africa, modern architecture developed especially in Nigeria, especially thanks to the presence of Jane Drew and Maxwell Fry, installed in this country as advisors for territorial planning in the English colonial Office. His main work was the University of Ibadan (1953-1959). It is also worth highlighting the presence of Walter Gropius, author of the University of Lagos (1963), as well as Ove Arup, author of several industrial buildings, and the English firms Godwin, Hopwood & Kuye, Watkins Gray International and James Cubitt & Partners, responsible for several buildings in Lagos.[477]​ The Israeli Arieh Sharon was responsible for the University of Ife (1960-1970).[478]​.

In South Africa, the Lecorbusierian influence was also received, as denoted in the work of Rex Martienssen"), author of the Peterhouse apartments in Johannesburg (1934-1935), inspired by the Savoye villa.[476] Another exponent was Norman Hanson"), who also shows the influence of the Swiss architect in his 20th Century Cinema in Johannesburg (1940). Some exiled German architects, most of whom trained at the Bauhaus, also developed their work in this country, such as Steffan Ahrends"), Helmut Stauch") and Bernard Pabst"). In the second post-war period, the influence came from the United States, especially in the construction of skyscrapers with metal structures and curtain walls, such as those built in Johannesburg by firms such as Skidmore, Owings & Merrill (Carlton Center Office Tower, 1973) and Hentrich Petschnigg. & Partners (Standard Bank Centre, 1970).[479]​.

Oceania

Australia remained faithful to the architecture of the colonial tradition until the end of the Second World War, when new international trends began to arrive. When this occurred, a variant of rationalism was developed that was innovative and not an imitation of the works of modern masters, especially thanks to Harry Seidler and Sydney Ancher. Austrian by birth, Seidler studied at Harvard's Graduate School of Design and Black Mountain College. He worked with Marcel Breuer in New York and with Oscar Niemeyer in Rio de Janeiro and, in 1948, opened his own studio in Sydney. His early works, such as the Rose Seidler house in Sydney (1948-1950), still show a canonical rationalism, but in the 1960s he evolved towards more minimalist forms, influenced by the painting of Frank Stella, with repetitive forms that combined rectangular and curved shapes, and a high quality of execution, as in the Australia Square Office Tower in Sydney (1961-1967, with Pier Luigi Nervi).[480] Other works of his were: the office of the Commonwealth Trade Group in Canberra (1970-1975), the Australian embassy in Paris (1973-1977) and the Riverside Center in Brisbane (1983-1986).[161] Sydney Ancher adapted the Miesian language to the local Australian environment, as in the Farley house in Warringah (1947), the English house in Saint Ives (1951) and the Ancher House in Neutral Bay (1957).[481] Other exponents of modern architecture were: Samuel Lipson"), Hugh Buhrich"), Frederick Romberg") and Mary Turner Shaw.[482]​.

In New Zealand there are no examples of modern architecture until after the Second World War. The first exponents were immigrants such as Heinrich Kulka") and Ernst Plischke, who however were poorly received by the local architectural community, still mired in the colonial style of previous decades. A first reaction against the prevailing academicism was that of Miles Warren and Peter Beaven"), who developed their work in different ways, the first with a certain brutalist influence (Dorset Street apartments in Christchurch, 1956-1957) and the second with a more florid style, as in his Lyttleton Road Tunnel Building (1963).[483]​.

Urban planning had a great development in the 20th century, since the progressive increase in the urban population since the beginning of the Industrial Revolution led to a growing interest in seeking new formulas and solutions to satisfy the housing and infrastructure needs of society. If in 1800 there were about 200 cities in the world with more than 20,000 inhabitants, with a total of 21.7 million inhabitants (2.4% of the total population), in 1950 there were 5,509 cities of that size, with 502.2 million inhabitants (20.9% of the total).[484] Rationalism, due to its progressive and social ideas, put great effort into developing urban planning theories that were universally applicable, with a special emphasis on hygienic and functional solutions, that satisfied all aspects inherent to the city, both economic and technological, cultural and ecological.[485]​.

The main rationalist urbanist was Le Corbusier, who set out his principles in Urbanisme (1925), where he developed his ideas about a functional city based on order and linearity. Already in 1922 he had outlined his project for a Ville contemporaine pour three milions d'habitants, in which he located an urban center with a series of office skyscrapers around a communications hub surrounded by various residential, service and leisure sectors, with abundant green areas and hierarchically ordered streets.[486]​ The buildings would be of three typologies: cruciform skyscrapers in the center, houses à redent[note 8]​ in the middle and immeubles-villas in the periphery.[488]​ In his 1925 book, Le Corbusier established four essential points about urban planning: decongest the city center, increase its density, increase the means of transportation and increase parks and open spaces. He also noted that "modern urban planning is born with a new architecture."[489] He applied this scheme to his Voisin Plan for Paris (1925) - not carried out -, in which he proposed the demolition of 40 hectares of old buildings on the right bank of the Seine, whose space would occupy a large green esplanade that would house nineteen tall skyscrapers with a cross plan, with straight roads and at different levels.[490]​[491]​ In 1933 he reformulated his theories with the name Ville Radieuse ("radiant city"), an almost utopian project that combined functionality with ecological concern, with giant blocks of apartments separated from each other to guarantee their exposure to the sun, large garden spaces, separation of functions and efficient communication routes. Le Corbusier was the "great creator of the utopia of the modern city in its physical aspect", according to Martin Meyerson.[492] In addition to Paris, Le Corbusier developed urban planning projects for São Paulo and Rio de Janeiro (1929-1930), Algiers (1930), Barcelona (1932-1935), Geneva (1933), Stockholm (1933), Antwerp (1933), Buenos Aires Aires (1938-1940), Saint-Dié (1945), Bogotá (1949-1952), Marseille (1950), Izmir (1950) and Chandigarh (1951-1965), the only one that was executed.[145]​.

The realization of all these ideas occurred in the Letter of Athens, one of the main manifestos of rationalist urbanism. It was written at the IV CIAM held in Athens in 1933, under the initiative mainly of Le Corbusier, although the writing was carried out by the Swiss architects Werner Max Moser and Rudolf Steiger. It was not published until 1942, anonymously, and in 1944 by Josep Lluís Sert with the title Can our Cities Survive?; Finally, in 1957 it was published under the signature of Le Corbusier. Its content focused on urban planning, with a functional city model opposed to traditional concepts, where the city is based on areas enabled for different functions, such as residential, economic and industrial or recreational (sports and recreation), together with green areas between the different spaces, all of them delimited and structured by rationally arranged road axes. For housing, Le Corbusier's bet was on high-rise buildings. According to his proposal, only the historical monuments, surrounded by green areas, would be saved from the old centers of the cities. This approach inspired many of the urban developments of the 1950s and 1960s.[493]​.

The first achievement inspired by the Athens Charter was the General Extension Plan for Amsterdam (Algemeen Uitbreidingsplan or AUP), prepared by Cornelis van Eesteren and approved in 1935. The objective was the expansion of the city towards the periphery and was prepared based on detailed statistical research, with a subdivision into neighborhoods of 10,000 homes separated by green areas and with open blocks oriented from north to south. The concentration of economic activities in the port center led to dense and compact growth, which however was optimally resolved with a pre-established organization to create cohesive neighborhoods and with a subdivision of tasks by units smaller than the neighborhood supervised by an architect. The plan is still in force and regulates the progressive growth of the city.[494]​.

After the Second World War, rationalist urbanism was applied to the reconstruction of cities devastated by war and its methodology became closer to capitalist economic principles, since its postulates of zoned fragmentation, mass production and prefabrication matched perfectly with capitalist industrial models. A paradigmatic model was that of the English new towns, which brought together the precepts of the garden cities advocated by Ebenezer Howard at the beginning of the century with the rationalist postulates.[495] It is especially worth highlighting the Greater London Plan to decentralize the English capital, approved in the New Towns Act of 1946. Between 1945 and 1951, fourteen new towns were created towns,[note 9]​ among which it is worth highlighting Stevenage (1946) and Harlow (1947), which show a certain influence of the Scandinavian neo-empiricism practiced at that time.[497]​ In the rest of Europe, an extensive program of reforms and new urban projects were also developed: in Scandinavia several new cities emerged (Vallingby"), Farsta and Skärholmen") in Sweden, Tapiola in Finland), as well as several regulatory plans in cities such as Copenhagen (Five Fingers Plan, 1947) or Helsinki, which expanded its municipal territory six times.[498]​ In France, Italy and Germany, most devastated by the war, priority was given to construction over urban projects, so the housing stock grew without adequate planning, except for some cases such as the development plans for Le Havre and Amiens drawn up by Auguste Perret in 1947-1954, the various Unité d'Habitation by Le Corbusier (1952-1964), the neighborhoods planned by the studio Candilis, Josic & Woods (Bagnols-sur-Cèze, 1956-1960; Toulouse-le-Mirail, 1961-1966), the Milan regulatory plan of 1953 or the Hansaviertel neighborhood in Berlin planned for the Interbau "International Exhibition of Berlin (1957)") of 1957.[499]​ In the Netherlands there was a greater relationship between architecture and urban planning, as in the case of Rotterdam, whose center was completely destroyed in 1940, for which a reconstruction plan drawn up by Cornelius van Traa") and approved in 1946 was drawn up.[500]​ In the eastern countries, the reconstruction of the cities was carried out under the academic style advocated. by the Stalinist dictatorship and only after Stalin's death did some more rationalist projects emerge, such as the housing blocks shown in models at the Brussels General Exhibition of 1958 "First Category General Exhibition of Brussels (1958)").[501]​.

It is also worth noting the urban planning in Israel, a country that grew considerably since its independence in 1948: if previously the Jewish population was 70,000 inhabitants - concentrated mainly in Haifa and Tel Aviv -, between 1948 and 1961 this figure tripled, making it necessary to build new cities, regulated with a territorial plan inspired by the English new towns directed by Arieh Sharon: between 1948 and In 1957, twenty-eight new cities were planned, including Beersheba and Ashdod; In the 1960s two more were created, Karminel") and Arad "Arad (Israel)").[462]

The main urban developments of the Modern Movement were Brasilia (Brazil), Chandigarh (India) and Islamabad (Pakistan). Brasilia (1956-1960), conceived as the country's new capital, was planned by Lúcio Costa, who was inspired by the Charter of Athens and designed a plan made up of two axes that intersect in the shape of a cross, with wide avenues and large spaces that provoke a great sensation of vastness - but equally of loneliness, as has been commonly criticized. In the central part are the official buildings and recreational areas, and around them are the residential, cultural and commercial areas, as well as green areas, stations, airport and all types of infrastructure.[395] Chandigarh was built as the new capital of Punjab between 1951 and 1965, with a project designed by Le Corbusier, Pierre Jeanneret, Maxwell Fry and Jane Drew. Also based on the Charter of Athens, Le Corbusier put into practice his theory of mixed sectors, in which residential areas are differentiated based on density,[435]​ and for residential buildings he applied the postulates of his Unité d'Habitation.[436]​ Islamabad was created as the new capital of Pakistan, with a design by Konstantinos Apostolos Doxiadis (1960), the creator of the concept of ekistics or science of habitat, which examines human settlements from multiple perspectives in search of techniques to solve their inherent problems. Doxiadis developed a purely rational layout and divided the city into sectors differentiated by their function or construction typology, starting from a central node from which the city would expand following a reticular plan.[442]​.

One of the greatest concerns of rationalist architects—especially in Germany—was that of social housing. The ravages of the First World War favored the rise of socialist ideas, to which numerous architects adhered, concerned with finding solutions for the housing needs of the working class. In France, the HBM (habitat à bon marché, "cheap housing") organizations promoted the construction of housing in the so-called "red belt" of Paris, and Henri Sauvage") devised his stepped residential buildings, such as the one on the rue des Amiraux (1913-1928). In the Netherlands, the Amsterdam School experimented with social housing with a sculptural aesthetic, while in Belgium the garden cities through cooperative movements. In Scandinavia, self-construction was encouraged. But the main boom in social housing occurred in Germany, especially during the Weimar Republic, with the phenomenon of siedlung (plural siedlungen, translatable as settlement or urbanization), residential complexes of houses or housing blocks located on the outskirts of large cities, rationally organized with the premises of large spaces, green areas and optimal sanitary conditions. sunlight and ventilation. Among the main achievements are those by Bruno Taut and Martin Wagner "Martin Wagner (architect)") in Berlin (six groups: Garden City Falkenberg, Siedlung Schillerpark, Großiedlung Britz, Wohnstadt Carl Legien, Weiße Stadt and Großiedlung Siemensstadt), by Otto Haesler") in Celle (Italienischer Garten, Georgsgarten) and by Ernst May in Frankfurt. (Römerstadt, Praunheim, Westhausen, Höhenblick), as well as the Weißenhofsiedlung in Stuttgart, the colony organized by the Deutscher Werkbund in 1927 in which numerous international architects participated. In contrast to the typology of houses with gardens sponsored by the siedlungen, in Austria the concept of Höfe (courtyard) was developed, large apartment blocks for collective housing, such as those in Red Vienna, among which the Karl Marx-Hof in Vienna, the work of Karl Ehn (1927), stands out. After the Second World War, large transitional housing plans arose to alleviate the ravages of war, generally financed by the states, while Le Corbusier proposed his Unité d'Habitation (like that of Marseille, 1947-1952), large housing blocks with all the services to constitute self-sufficient entities.[502]​.

The Modern Movement also placed special interest in design, decoration and interior design. One of the most innovative movements in the field of design was the Bauhaus School which, compared to the excessive ornamentation of art deco, introduced a more rational and functional design concept, more adapted to the real needs of people. This school sought to break the barriers between art and crafts, with some influence at the beginning of Arts & Crafts, while later it opted for industrial production. Its objective was "the collective work of art, the Building, within which there were no barriers separating the structural arts from the decorative arts."[119] Students at the school learned theories of form and design, as well as workshops in stone, wood, metal, ceramics, glass, weaving, painting, theater and photography.[503] Its design was based on simplicity, geometric abstraction and the use of primary colors and new technologies, as was evident in the tubular steel furniture. created by Marcel Breuer, the Barcelona chair by Ludwig Mies van der Rohe and Lilly Reich or the lamps designed by Marianne Brandt. In this school, creators stood out - in addition to those previously mentioned - such as László Moholy-Nagy, Oskar Schlemmer, Johannes Itten, Paul Klee, Josef Albers, Vasili Kandinski, Gerhard Marcks or Wilhelm Wagenfeld. the sans serif. In 1925 the Bauhaus founded its own company to market its designs, the Bauhaus GmbH, which published a catalog with its products.[505]​.

Heir to the Bauhaus was the Hochschule für Gestaltung (Higher School of Projection), later called Neues Bauhaus (New Bauhaus), founded in 1953 by Max Bill in Ulm. His design works were characterized by their geometric appearance and minimalism, which became known as the "Ulm style." In the first phase, the school was oriented towards fine arts and crafts and included teachers from the former Bauhaus such as Josef Albers and Johannes Itten. A second phase was marked by the change of management in 1956 from Max Bill to Tomás Maldonado, who reoriented the school towards industrial production. Architects and designers such as Walter Gropius, Mies van der Rohe, Frei Otto, Charles Eames and Richard Buckminster Fuller taught at the Ulm Bauhaus.[189] Bill himself was a designer of notable creativity: he had been a student at the Bauhaus and in the 1930s he worked as a painter, sculptor, architect and graphic designer, while in the 1940s he began in industrial design, with creations such as his aluminum wall clock for Junghans (1957), his wristwatches and his minimalist stool Ulmer Hocker (1954).[506]​.

In the century, industrial design gained progressive prominence, based on intellectual creation and functional design, with an increase in experimentation with new materials (plastic, fiberglass) and greater attention to market needs.[507]​ The basis of industrial design is found in functionalism "Functionalism (architecture)"), a theory that argues that an object that fulfills its function and is made with economy of materials is intrinsically beautiful. This would exclude aesthetics in the design of objects, although such an extreme is rarely put into practice in its entirety. One of the precedents of this theory was the architect Louis Sullivan, who stated that "form follows function", as well as Otto Wagner, who stipulated that "nothing that is not practical can be beautiful."[508] In Germany, architects and designers such as Peter Behrens, Richard Riemerschmid and Bruno Paul, and workshops and associations such as Deutsche Werkstätten, Deutscher Werkbund and the Bauhaus, laid the foundations of industrial design in an early phase. In France, the pioneer was the architect Le Corbusier, who proclaimed the "absolute expressive autonomy of industrially produced objects" and pointed out as basic aspects of the new design the purity of lines, the functionality of the materials and the luminosity of the surfaces.[509]​ After the closure of the Bauhaus by the Nazis in 1933, most of its components were moved to the United Kingdom or the United States, countries that picked up the baton of industrial design.[510]​ In the In the United Kingdom, design had its precedent in the Arts & Crafts workshops. In 1915, the Design and Industries Association was founded with the aim of promoting design and, in 1930, the Society of Industrial Artists was created to bring together professionals in the sector.[511] In the United States, the pioneer was the architect Frank Lloyd Wright, until the emergence of design in the 1930s with figures such as Henry Dreyfuss, Raymond Loewy and Walter Dorwin Teague. In that decade, some Bauhaus masters such as Ludwig Mies van der Rohe, Walter Gropius and László Moholy-Nagy also established themselves, who taught a new generation of designers. Later Charles Eames, George Nelson and Harry Bertoia stood out. In 1944 the Society of Industrial Designers was founded, in 1948 the National Association of Schools of Design and, in 1957, the Industrial Design Educational Association.[511]​.

Later, in Europe, industrial design had two main currents: the Scandinavian and the Italian. The first, represented by Arne Jacobsen, Alvar Aalto, Eero Saarinen and Poul Kjærholm, had its roots in popular art and was based on the naturalness and simplicity of the forms as a fundamental premise of the design, as well as the use of natural materials, although without disdaining steel, which they used frequently. The main fields covered by Scandinavian design were furniture, ceramics, metalwork and glass. For its part, Italian design was more daring and extravagant, with a predilection for bright colors, use of artificial materials such as resin, plastic and conglomerate, as well as steel and more "noble" materials such as marble, and with a creative freedom that ranged from the austerity of Ettore Sottsass, through the rationalism of Joe Colombo, to the refinement of Gae Aulenti. In Spain, a school of designers of notable quality also began in the 1930s, marked by a certain expressiveness, a generally small size of objects and a certain test character, with high-quality prototypes that did not always find an industrial outlet. The starting point is at the GATCPAC, a pioneer in the introduction of modern design in Spain - in 1931 they opened their commercial premises, called MIDVA (Furniture and Decoration of Current Housing) -, with figures such as Josep Lluís Sert, Josep Torres Clavé and Antoni Bonet Castellana; Later it is worth mentioning Antoni de Moragas, Oriol Bohigas, Carlos de Miguel"), José Antonio Coderch, Miguel Milá and Antonio Fernández Alba. In 1955 the Spanish Society of Industrial Design was founded and, in 1960, the Industrial Design Group (ADI-FAD).[512]​.

In the field of interior design, the maximum premise after the First World War was innovation, always subordinated to functionality, leaving out aspects such as comfort or convenience, which were not considered essential. Interior design stopped looking to the past, stopped paying attention to regional styles or forms; They were looking for something new and valid for any geographical area. In the 1920s, the dominant concepts were technology and hygiene: domestic objects were designed according to the latest technological advances and interior design was based on open, sunny and ventilated spaces. As most interior designs were carried out by architects, they were generally subordinated to the external form of the building, which determined the interior planning and type of furniture. On the other hand, rationalism's commitment to the open floor plan led to interiors without rooms, with spaces delimited by screens or by the furniture itself, thereby neglecting aspects such as privacy, noise or smells.[513]​.

The main piece of furniture that was the object of special interest in its design was the chair: according to Christopher Wilk, "no era has produced so many chair designs by architects. Virtually every architect and designer worth mentioning felt obliged to direct their attention to the design of at least one chair. Faced with the excessive coldness and asepsis of these designs, in the 1930s—especially in the United Kingdom—a “comfortable modernism” was promoted, such as that developed by the English firm Isokon, based on greater comfort and aesthetic appearance, for which they turned to wood as a material; Breuer himself made a lounge-chair for Isokon in 1936. On the other hand, the exhibition British Industrial Art in Relation to the Home of 1933 showed the Minimum Flat ("minimum apartment") by Wells Coates, with a kitchen and a bathroom of strict functional design. its simplicity, low cost and mass production; These furniture influenced Le Corbusier and Mies van der Rohe, who used them in the L'Esprit Nouveau pavilion of 1925 and the Weißenhofsiedlung of 1927, respectively. Wood also played a leading role in Scandinavian interior design, a "natural modernism" advocated above all by Alvar Aalto. Apart from furniture, modern interior design gave little consideration to the use of fabrics or other ornaments, and even for the color of the walls, exclusively white was recommended.[516] It is worth highlighting the kitchen design prepared by the Austrian architect Margarete Schütte-Lihotzky, who in 1925 collaborated with Ernst May on his collective housing project for Frankfurt, for which she created the so-called Frankfurt kitchen, provided with built-in furniture and elements. prefabricated, unadorned and well-lit spaces, with a practical, cheap and standardized design.[517]​.

After the Second World War, interior design opted for a more aesthetic appearance, with bright and cheerful colors that made one forget the horrors of war. Postwar shortages of materials and labor generally led to smaller houses and apartments, with well-placed and easy-to-use furniture and appliances. Demand grew for furniture, largely destroyed during the war, with simple design and mass production, such as that advocated by the Utility plan in the United Kingdom. Gordon Russell") designed a line of affordable and comfortable modern designer furniture, inspired by Arts & Crafts. In the United States, the Knoll company also opened a line of mass-produced contemporary furniture. In Germany, the Thonet company launched a series of electronically molded plywood furniture, which was cheap, flexible and resistant. On the other hand, in 1946 the first molded plastic chair was created. In the 1950s the furniture became lighter and smaller, like the one designed at the American Cranbrook Art Academy by Eliel Saarinen or Charles Eames, more organic and comfortable. Isamu Noguchi designed the first table with a glass cover, as well as the first lantern-shaped paper lampshade, then began the leadership in design promoted in Sweden, more minimalist and equally comfortable, flexible, hygienic and affordable, as in the work of Alvar Aalto and Arne Jacobsen. It was here that the flatpack or removable furniture was developed. Ikea. In the United States, open-plan houses emerged, with open spaces, such as those designed by Eero Saarinen and Charles and Ray Eames, with unique spaces subdivided only by changes in the floor covering and by the furniture - especially the storage units of Lecorbusierian design -, while the rooms were placed at mid-height, on a mezzanine. The kitchens became larger and more technological, efficient and utilitarian, although their design was functional. It led to a certain masculinization of these spaces.[518]​.

The main characteristics of modern furniture were: functionality, suppression of all superfluous ornamentation and minimal decoration coming from the same lines of force (shape, material), structure as a total base of the furniture without additions, standardized canons of universal utility and open, clear and simple forms. Prouvé, Eileen Gray, Robert Mallet-Stevens, Pierre Chareau and René Herbst.[520]​.

In general, the interior design of the Modern Movement has been criticized for its lack of comfort and the high cost of its industrial production, since until the 1960s the industry did not achieve standards compatible with the mass production of modern design objects. Thus, the interior decoration of modern architects was limited at the time to an elite of high-income consumers, which contradicted the social principles defended by rationalism.[521]​.

• - Teapot designed at the Bauhaus by Marianne Brandt (1924).

• - Cantilever Chair (1926), by Marcel Breuer.

• - Weißenhof Chair (1927), by Ludwig Mies van der Rohe and Lilly Reich.

• - Paimio Chair (1929-1933), by Alvar Aalto.

• - BKF Chair (1937), by Antoni Bonet Castellana, Juan Kurchan and Jorge Ferrari Hardoy.

• - Utero Chair (1947-1948), by Eero Saarinen.

• - Eames Lounge Chair (1955), by Charles and Ray Eames.

• - Wall clock designed by Max Bill for Junghans (1957).

• - Egg Chair (1958), by Arne Jacobsen.

• - Modern architecture.

• - Functionalism (architecture) "Functionalism (architecture)").

• - Organic architecture.

• - Architects in the Modern Movement.

• - Nordic design

• Accept

• Stockholm Exhibition.

• - Urban vitality.

• - Wikimedia Commons hosts a multimedia category on Rationalism.

• - Wikimedia Commons hosts a multimedia category on International Style.

• - Wikimedia Commons hosts a multimedia category on Modern Movement.

It is advisable to first analyze the terminology applied to this movement. Except for small nuances, in general it can be considered that rationalism, International Style and Modern Movement are synonymous concepts.[1][2][3][4] As its etymology indicates, rationalism comes from reason and has its origin in the claim of the new architecture to rationalize construction processes. Rationalism was the heir of the Enlightenment and the Industrial Revolution, the culmination of a long process of application in architecture of the new mechanization processes initiated with the industrial era. This process evolved in parallel to social advances, with a certain utopian component of application of the values ​​of architecture and urbanism to the improvement of society: industrialization, used in a "rational" way, would serve, according to the theorists of the movement, to solve social injustices and create an urban environment that optimally encompasses the majority of the population.[5] Some historians point the origin of the term to this phrase by Erwin Piscator:

The term "International style" (in English: International style) comes from the exhibition Modern Architecture - International Exhibition organized by Henry-Russell Hitchcock and Philip Johnson at the Museum of Modern Art (MoMA) in New York in 1932 and in the book published by both The International Style: Architecture since 1922. Despite its ambiguity, the term made a fortune and is the most used in the Anglo-Saxon world to designate the most orthodox phase of rationalism. For Hitchcock and Johnson, the International Style encompassed the most symptomatic productions of both rationalism and neoplasticism, characterized by a rational language based on industrial production.[7]​ Sometimes the term rationalism is limited to Europe, while International style would describe it worldwide.[8]​ Another term used in this context is "internationalism", from the book Internationale Architektur by Walter Gropius (1925).[9]​.

The term "Modern Movement" (in English: Modern Movement) comes from the book Pioneers of Modern Movement from William Morris to Walter Gropius (1936), by Nikolaus Pevsner, and would be more inclusive, since it would bring together rationalism with expressionism, cubism, futurism, neoplasticism and constructivism "Constructivism (art)"), generically considered as a "pre-rationalism" (or "protorrationalism"). The author's intention was to point out the convergence of several stylistic currents towards a new way of conceiving architecture during the first decades of the century. According to Pevsner, "it is essential to understand the Modern Movement as a synthesis of the Morris movement (Arts & Crafts), the development of steel construction and art nouveau." It is interesting to note that already in 1902 the architect Otto Wagner had used the same term in the preface to his book Moderne Architektur.[10] However, in recent times some historians have criticized some of Pevsner's formulations, especially regarding the alleged loss of historical roots in modern architects, pointing out for example that Le Corbusier was largely inspired by classical Greco-Roman architecture and Ludwig Mies van der Rohe in the work of the neoclassical architect Karl Friedrich Schinkel. Another of the premises questioned has been that of a common supranational style, against which a wide divergence of nationally based criteria has been pointed out in each of the countries where the movement developed, although on numerous occasions they converged on common criteria. Thus, compared to the initial postulates of Pevsner and Siegfried Giedion, from the 1970s onwards various historians criticized the concept of the Modern Movement, such as Reyner Banham, Bruno Zevi or Manfredo Tafuri, while Charles Jencks began to speak of "modern movements" in the plural.[11]​.

It should be noted that in some countries, especially in the Anglo-Saxon sphere, the term "modernism" is used synonymously with the Modern Movement. However, in Spanish this term is used for the artistic style "Modernism (art)") developed between the end of the century and the beginning of the century also known as art nouveau in France, Modern Style in the United Kingdom, Jugendstil in Germany, Sezession in Austria, Nieuwe Kunst in the Netherlands or Liberty in Italy.[12]​.

Finally, it should be noted that Modern Movement is not the same concept as modern architecture, which is the architecture of modernity, a cultural process that began with the Enlightenment in the century based on science and progress, linked to philosophical positivism. It therefore includes the centuries , and , that is, until the present day, because although postmodern art has questioned the validity of modernity since the 1980s, historians do not agree, and there are even experts—such as Valeriano Bozal—who point out that postmodernism is just another phase of modernity, precisely the one in which it reflects on itself.[13]​.

Contenido

Los orígenes del racionalismo son difusos y proceden de una lenta evolución desde mediados del siglo hasta los años 1920, en que empezó a cobrar conciencia en una nueva generación de arquitectos, críticos y estudiosos de la arquitectura la constatación de que las realizaciones de esa época compartían unos rasgos estilísticos comunes y un programa moderno y dinamizador de los procesos constructivos y urbanísticos. En la génesis del racionalismo se encuentran los adelantos tecnológicos que propiciaron en la segunda mitad del siglo la arquitectura de cristal y hierro, el movimiento Arts & Crafts, la edificación de los primeros rascacielos propiciada por la Escuela de Chicago "Escuela de Chicago (arquitectura)"), la formulación de la teoría funcionalista "Funcionalismo (arquitectura)") por Louis Sullivan, algunos postulados de la arquitectura modernista —especialmente la Sezession vienesa— y la obra de varios arquitectos individuales —en especial Frank Lloyd Wright— hasta desembocar en las corrientes de vanguardia de inicios del siglo , que suelen considerarse como un prerracionalismo.[15]​.

Hay que considerar también como motor de la nueva arquitectura en la transición entre los siglos y los cambios tecnológicos producidos en la llamada Segunda Revolución Industrial, tales como la invención del hormigón armado (1854), el procedimiento Bessemer para la elaboración del acero (1856), la invención de la dinamo "Dinamo (generador eléctrico)") para generar electricidad como fuerza motriz (1869), el teléfono (1876), los experimentos de Galileo Ferraris sobre el campo magnético rotatorio que permiten el transporte a distancia de la energía hidráulica (1883), la bombilla eléctrica (1879), el motor de explosión (1885), etc. Todos estos factores ayudaron a la industria de la construcción y lanzaron a la arquitectura a una nueva forma de construir de múltiples posibilidades.[16]​.

Un primer factor determinante en la aparición del racionalismo fue la apertura en 1919 de la Bauhaus, una escuela de arquitectura, arte y diseño dirigida por Walter Gropius que preconizaba un estilo funcionalista de líneas sencillas y basado en la producción industrial. Durante los años posteriores al fin de la Primera Guerra Mundial empezaron a descollar varios arquitectos que fomentaban en sus obras las premisas racionalistas, como el propio Gropius, Le Corbusier y Ludwig Mies van der Rohe, considerados los máximos exponentes de este movimiento, que ayudaron a su difusión internacional. Poco a poco el nuevo estilo se fue difundiendo gracias a concursos, congresos y exposiciones: en 1922, el concurso para la nueva sede del Chicago Tribune dio a conocer propuestas de Gropius, Adolf Meyer "Adolf Meyer (arquitecto)"), Max Taut y Hans Scharoun; en 1925, Le Corbusier construyó para la Exposición de Artes Decorativas e Industrias Modernas de París el pabellón de L'Esprit Nouveau, en el que expuso sus nuevas teorías urbanísticas; en 1927, la exclusión de Le Corbusier del concurso para la sede de la Sociedad de Naciones en Ginebra provocó un gran escándalo, hecho que repercutió en otorgarle más fama; también en 1927, Mies van der Rohe organizó en Stuttgart una exposición de arquitectura dedicada a la vivienda (Die Wohnung) que promovió la construcción de treinta y dos casas —la urbanización Weißenhofsiedlung—, entre edificios y viviendas unifamiliares, que supuso un gran hito para el nuevo estilo:[17]​ la internacionalidad del proyecto llevó al profesor Paul Schmitthenner") a afirmar que «estamos alcanzando la fórmula del estilo internacional del siglo ».[18]​ Otras exposiciones en las que participaron arquitectos racionalistas fueron: la Exposición Internacional de Barcelona (1929) "Exposición Internacional de Barcelona (1929)"); el Salón de los Artistas Decoradores del Grand Palais de París (1930); y la Bauausstellung (Feria de la Construcción) de Berlín (1931).[19]​.

El mayor acontecimiento que supuso la oficialización del racionalismo fue la fundación en 1928 en La Sarraz (Suiza) del Congreso Internacional de Arquitectura Moderna (CIAM), una asociación internacional de arquitectos encargada de celebrar congresos para debatir los nuevos principios de la arquitectura y ayudar a su difusión internacional.[20]​.

Otro de los principales acontecimientos que ayudaron a difundir el nuevo estilo fue la exposición Modern Architecture - International Exhibition, organizada por Henry-Russell Hitchcock y Philip Johnson en el MoMA de Nueva York en 1932, de la que surgió asimismo el libro publicado por ambos, The International Style: Architecture since 1922, que aportó el término Estilo internacional para designar al movimiento. Estos autores se centraron más en los aspectos formales que unían las diversas manifestaciones de este movimiento que no en sus premisas teóricas e incluso utópicas. Señalaron como principales características de este estilo el rechazo al eclecticismo "Eclecticismo (arte)") historicista, el empleo de materiales como el acero, el vidrio y el hormigón, el uso de la planta libre y la «concepción de la arquitectura como volumen más que como masa».[21]​.

El racionalismo tuvo una rápida difusión por toda Europa y arraigó especialmente en Alemania, Francia, Países Bajos, Austria, Checoslovaquia, Suiza, Reino Unido —gracias especialmente a arquitectos alemanes huidos del nazismo—, Italia y España. En los años 1930 el racionalismo tuvo un nuevo centro difusor en Estados Unidos, adonde llegaron numerosos arquitectos europeos exiliados a causa del nazismo alemán, el fascismo italiano y el comunismo soviético.[22]​ Sin embargo, en esa década el movimiento entró en una fase de ciertas dudas y de críticas hacia su excesivo formalismo y su frío mecanicismo, alejado de las necesidades humanas. El propio Le Corbusier se fue distanciando de su purismo inicial y empezó a considerar la máquina como una herramienta y no un fin en sí mismo. Pese a todo, el racionalismo continuó siendo el estilo hegemónico a nivel internacional hasta prácticamente los años 1960.[23]​.

Tras la Segunda Guerra Mundial el movimiento comenzó a decaer, pero todavía se siguió construyendo en estilo racionalista hasta los años 1960 e incluso 1970, en convivencia con otros nuevos estilos que fueron surgiendo.[22]​ De hecho, en la posguerra la urgencia de reconstruir las ciudades devastadas en la contienda coadyuvó a la pervivencia del estilo, ya que frente a la búsqueda de nuevos estilos se prefirió uno ya consolidado. Ello se produjo en paralelo a la definitiva universalización del lenguaje racionalista, ya que su mayor difusión en esos años se produjo en países emergentes como Brasil, India, México y Venezuela.[24]​ Esta globalización del movimiento llevó pareja una diversificación del mismo, ya que tuvo que adaptarse a las diferentes tradiciones constructivas de países de muy diversa cultura, así como a diversas condiciones climáticas, económicas y sociales.[25]​ Incluso en Estados Unidos el Estilo internacional se fue regionalizando, como se demuestra por la sustitución en numerosos casos de los esqueletos de acero por madera, por influencia de las casas usonianas de Frank Lloyd Wright.[26]​.

La difusión del internacionalismo tras el conflicto bélico corrió a cargo principalmente de la Unión Internacional de Arquitectos (Union Internationale des Architectes, UIA), fundada por el francés Pierre Vago en colaboración con el inglés Patrick Abercrombie, el italiano Saverio Muratori"), el portugués Carlos João Chambers Ramos y el ruso Viacheslav Popov"); Vago fue su secretario general entre 1948 y 1968. El primer congreso se celebró en París en 1948 y desde entonces cada tres años en un país distinto. Otro órgano de difusión fue la revista Architectural Review, así como instituciones como la Universidad de Harvard, la Ulm Bauhaus y la Architectural Association School of Architecture del Reino Unido, y otras de nueva creación como la Middle East Technical University de Ankara y el Asian Institute of Technology de Bangkok.[27]​.

Sin embargo, tras la contienda mundial el Estilo internacional se fue convirtiendo en un método de construcción sistemático y perdió algo de su esencia inicial y de su componente utópico de un arte al servicio de la sociedad. La confianza en las nuevas tecnologías, en el arte como instrumento de educación para el pueblo, en una estética universal que comportase una ética universal, se fueron diluyendo, y el movimiento se fue reduciendo a un estilo reglamentado, que no dejaba espacio para la innovación ni la creación individual, para la subjetividad o la relación con la naturaleza.[28]​ Su evolución estilística fue hacia un cierto eclecticismo "Eclecticismo (arte)") —según Jürgen Joedicke— o manierismo —según Josep Maria Sostres—, con dos posibles vías de realización: la «imitación mecánica e impersonal de los grandes ejemplos» (Sostres) o la contextualización regionalista, como la practicada por el neoempirismo escandinavo, el brutalismo británico, el neorrealismo "Neorrealismo (arquitectura)") y neoliberty italianos o la Escuela de Barcelona "Escuela de Barcelona (arquitectura)") en España.[29]​.

El principio del fin de este movimiento se escenificó en el IX congreso del CIAM, en el que un grupo de arquitectos disidentes se organizó en el llamado Team X, que propugnaba una evolución hacia un estilo más realista y de utilidad social, que se concretó en un nuevo estilo denominado brutalismo. Este grupo acusaba al CIAM de haber patrocinado el Estilo internacional imponiendo «conceptos mecánicos de orden», sin tener en consideración las necesidades emocionales del ser humano o las especificidades territoriales de los diversos países en que se desarrolló el estilo. El propio Philip Johnson confesó en 1996 que «nuestra así llamada arquitectura moderna era demasiado antigua, glacial y llana».[30]​.

Aunque el fin del racionalismo como estilo puede situarse en el primer lustro de los años 1960, cabe remarcar que hasta los años 1970 y primeros 1980 aún se construyó en ese estilo —de forma más o menos ortodoxa— en numerosas partes del mundo, especialmente en países emergentes que habían llegado con cierto retraso a la modernidad. El proceso descolonizador iniciado en África y Asia tras la Segunda Guerra Mundial propició el auge constructivo de estos nuevos países, que necesitaban nuevas infraestructuras y edificios gubernamentales, y que adoptaron el Estilo internacional como forma de equiparar la construcción de un nuevo estado con una imagen moderna y progresista. En muchos casos, esta arquitectura resultó estereotipada y acontextualizada, con una cierta apariencia de trasplante de tipologías occidentales a países de distinta tradición cultural, sin atender a las condiciones sociales, geográficas y económicas de estos países.[31]​.

CIAM

The International Congress of Modern Architecture (in French: Congrès International d'Architecture Moderne) was founded in La Sarraz (Switzerland) in 1928 to promote interaction between architects and urban planners from around the world in order to exchange ideas and compare the styles and techniques used in different places around the world.[32] Originally, the meeting was motivated as a response to the postponement of the Modern Movement in the competition for the headquarters of the League of Nations in Geneva, against which the architects of the new movement wanted to offer a common front.[33]​ Among the founders of CIAM was Le Corbusier,[note 1]​ and Siegfried Giedion was its first secretary until 1956.[35]​ As the executive body of CIAM, CIRPAC, the International Committee for the Resolution of Problems of Contemporary Architecture (in French: Comité International pour la Résolution des Problems of Contemporary Architecture). In 1959 its final dissolution occurred; By then the congress had more than thirty affiliated countries and about three thousand members.[36]​.

Four phases are usually noted in the history of the CIAM: the founding cycle of the congresses (1928-1933), the crisis motivated by Nazism and the series of emigrations of numerous architects (1934-1945), the refoundation and expansion of the congress (1945-1953) and the process of agony of the movement motivated by the protest process of the youngest architects. (1953-1959).[33]​.

At their first meeting, Le Corbusier was in charge of drafting the agenda to be discussed, which included the following topics: modern technology and its consequences; standardization; the economy; urban planning; youth education; the realization: architecture and the State.[37] A declaration was drafted that maintained that "to benefit a country, architecture must be closely related to the general economy. True performance will be the result of rationalization and standardization, and sufficient production to fully satisfy human demands."[38] Three functions were also identified as primary objectives of urban planning: living, working, entertainment.[39]​.

In 1929 the second congress met in Frankfurt (Germany), focused on the issue of "minimum housing." CIAM III took place in 1930 in Brussels (Belgium), on the "rational urbanization" of space. The fourth congress, dedicated to the "functional city", was to be held in Moscow, but for political reasons it was finally held in Athens (Greece) in 1933, aboard the yacht Patris II; In it the so-called Letter of Athens was agreed. In 1937 CIAM V was held in Paris (France), under the premise of "housing and leisure." The Second World War paralyzed the congresses and fostered the rise of the American group; Josep Lluís Sert, exiled in that country, published the book Can Our Cities Survive? in 1943, where he collected the postulates of the CIAM and became the reference work of rationalism in the Anglo-Saxon sphere. After the war, CIAM expanded to Asia, Africa and Latin America, and the Le Corbusier-Gropius-Giedion trio began to lose influence. In 1947 CIAM VI took place in Bridgwater (England), focused on the reconstruction of cities devastated by war. CIAM VII was held in Bergamo (Italy) in 1949, on architecture as art. In 1951, CIAM VIII was housed in Hoddesdon (England) and focused on the center of the city, with a first split between orthodox and innovative positions due to the approach of new concepts such as the symbolic dimension and the human scale. CIAM IX took place in 1953 in Aix-en-Provence (France) and focused attention again on generational disputes and the founding of Team X by Jaap Bakema, Georges Candilis, Aldo Van Eyck and Alison and Peter Smithson. In 1956 CIAM X was held in Dubrovnik (Yugoslavia), focused on the as an alternative to that of Athens. In 1957 the national groups were dissolved and Jaap Bakema was elected general secretary. The last congress, CIAM XI, took place in 1959 in Otterlo (Netherlands) and meant the dissolution of CIAM.[40]​.

The MoMA exhibition of 1932

The exhibition Modern Architecture - International Exhibition was held at the Museum of Modern Art (MoMA) in New York between February 9 and March 23, 1932. It subsequently toured the United States for six years.[41] Its curators were the critic Henry-Russell Hitchcock and the architect Philip Johnson, who chose the most representative works of the new style in Europe and the United States—with the only exception outside these continents of the laboratory building of electricity from the Ministry of Public Works in Tokyo, by Mamoru Yamada. The selection criteria were basically aesthetic, which is why they left aside the most programmatic aspects of the new architecture, especially its social and economic dimensions, a fact for which Hitchcock and Johnson's proposal was criticized. According to the curators, the works included in the new trend had to meet a series of parameters, such as the absence of ornamentation, the composition in terms of volume and not mass, in modular regularity and not in axial symmetry. As for architects, they left out the work of the movement's pioneers, such as Peter Behrens, Auguste Perret, Adolf Loos, Antonio Sant'Elia and Frank Lloyd Wright, and established Le Corbusier, Walter Gropius, Ludwig Mies van der Rohe, Jacobus Johannes Pieter Oud, Gerrit Rietveld and Richard Neutra as paradigms of the new movement.[42]

The work of sixty-seven architects was exhibited.[note 2]​ The majority of projects exhibited came from Germany, followed by the United States. By architects, the majority were projects by Gropius, Le Corbusier and Mies van der Rohe. The selection was made by the curators themselves, whether they were projects that they were familiar with or one of them, with few exceptions of recommendations from other people they trusted, such as Richard Neutra, who recommended the Tokyo electrical laboratory, by Mamoru Yamada, or Bruno Taut, who recommended the Moscow electrophysical laboratory, by Iván Nikolayev and Anatoli Fisenko").[44]

With the same premises as the exhibition, Hitchcock and Johnson published the same year the book The International Style: Architecture since 1922, which gave its name to the movement in the Anglo-Saxon world. In the book they analyzed the work of seventy-two architects from fifteen countries, with the premise that they represented a new architectural style of an international nature. In the foreword, MoMA director Alfred Barr noted that the authors had demonstrated that "there is today a modern style as original, consistent, logical and international as any in the past."[45]

In 1951, Hitchcock made the following retrospective analysis of the parameters used for the exhibition:

Philip Johnson also reviewed the parameters of the exhibition in the 1960s and pointed out as the main characteristics of the International Style structural honesty, repetitive modular rhythms, flat ceilings, clarity expressed by glass surfaces, the box as a container and the absence of decoration.[46]​.

Rationalism was a heterogeneous movement with both geographical and chronological origins that were difficult to pin down. It could be said that it was rather a confluence of different styles that converged on common characteristics, which became more clearly evident after the First World War. Its general characteristics were forged little by little in the work and contributions of all the movements and architects that are considered antecedents of this style. When these characteristics were analyzed more thoroughly, it was possible to determine that the majority of creations of this new style were based on several main points: use of a functionalist language, use of simple geometric shapes and regular structures, tendency towards a vertical-horizontal arrangement, renunciation of ornamentation and use of industrial-type materials (concrete, steel, glass).[47] Despite this, it is difficult to speak of a homogeneous style and, in fact, many rationalist architects stated that they did not They had style, but rather theirs was "a purely rational form of design."[48]

The ideological postulates of rationalism were based on progress and modernity, with a decided commitment to industrial and mechanized production, as well as a rational organization of work. With a tendency towards a progressive and egalitarian political ideology, they wanted to develop a new constructive language that would serve to renew society, which was especially reflected in their interest in urban planning and social housing.[1] Thus, it could be said that the foundations of rationalism are found in the "conciliation between technological progress and social commitment", according to Jeremy Melvin.[49]​.

One of the main premises of the Modern Movement was functionalism "Functionalism (architecture)"), the subordination of architectural language to its function, leaving aside any aesthetic or accessory consideration for the main objective of construction: "form follows function", in the words of Louis Sullivan. Thus, any construction form must reflect the use for which it was designed. According to this theory, even the construction elements - such as beams and pillars - must be left visible, as they are part of the formal design according to which a structure is planned. To achieve this, industrial production and technological advances must contribute, which are tools made available to the architect to optimize their construction work.[50]​.

Within the industrial society and the capitalist economy, the rationalist architect was required to provide maximum functionality and optimization of resources, to develop the best designs with the most economical industrial criteria; He had to consider all the components of life in society, so he had to take responsibility "from the spoon to the city", as they used to say at the time. In general, the majority of rationalist architects had social concerns and considered it a duty of the State to guarantee minimum living conditions (existentzminimum) to the population.[51]​ In rationalism, all the constituent elements of the architectural work were subordinated to function, so function and style are equated.[9]​.

Among the main stylistic features of rationalism are: rectilinear and orthogonal forms, composition in volume rather than mass, uniform and visible structures, absence of axial symmetry, the use of pilotis as a support for the structure, flat roofs, empty central patios, open plan interiors, use of overhangs - especially in balconies and terraces -, facades without ornaments, white walls and rectangular windows, linked in an elongated band and run in the façade plane.[52]​[45]​ Also characteristic is the use—especially in skyscrapers—of the curtain wall (curtain wall), a type of self-supporting glazed façade, independent of the resistant structure of the building, generally built by the repetition of a modulated prefabricated element, which is usually composed of an extruded aluminum frame and a glass panel.[53]​ Another commonly used element is brise soleil, a type of solar protection for windows and balconies, like a blind or lattice, which can be made of various materials, from wood to the concrete commonly used by Le Corbusier.[54]​ It should be noted that rationalist architecture received a certain influence from nautical design, and Le Corbusier even added numerous photographs of ships and ocean liners in his book Vers une Architecture (1923).[55]​.

The main aesthetic factor of the new style was the absence of applied decoration, conceived as a way of eliminating superficiality. The new premise was simplicity, based mainly on industrial materials, a structural order based on regularity versus angularity and on a harmony based on proportion and geometry, and on a design centered on a skeleton of columns (concrete or metal pillars) instead of a mass structure, with a smooth and seamless surface, of smooth materials - preferably metal and glass -, with windows that did not interrupt the perfection of the façade, if possible with light metal frames, and a chromaticism focused on the natural color of the material. They also considered relevant the choice of the place to build and its relationship with the environment, within which the external walls of the building - such as terraces and pergolas - are considered extensions of it, as are the walls and paths of the gardens, whose rectilinear planimetry contrasted with the work of nature. On the other hand, within the ornamental aspect, they considered the inclusion of paintings and sculptures in the building as independent elements that should not degenerate into simple decoration, but should beautify autonomously. In that sense, Hitchcock and Johnson pointed out abstract wall paintings as the ideal complement to modern architecture.[56]​.

Rationalist architecture - especially design - maintained close contacts and influences with the rest of the arts, especially painting, and within this that of avant-garde movements such as neoplasticism, suprematism and constructivism "Constructivism (art)"), all of them with an abstract tendency, from which they took some of their designs and the preference for primary colors, as well as experimentation with various materials and a design based on basic and proportionate shapes. Some of the painters who most influenced the movement were professors at the Bauhaus or maintained contacts with this institution, such as El Lissitzky, Theo van Doesburg, Vasili Kandinsky, Paul Klee, Johannes Itten and László Moholy-Nagy.[57]​.

Rationalism was nourished by an extensive theoretical corpus prepared by some of its most prominent representatives, such as Gropius and Le Corbusier. In 1925, Gropius published Internationale Architektur, where he related his work to that of other architects such as Le Corbusier, Oud and Wright, and pointed out that they all shared a functional vision of architecture, with a logical conception of the work and economic planning to optimize money, materials, time and space. He also noted that "the uniformity of the appearance of modern buildings, arising from global travel and technology, overcomes the natural borders that continue to isolate individuals and peoples, creating a bridge between all cultural regions."[58]​.

Le Corbusier published several books on art and architecture, such as Vers une Architecture (1923), L'Art Décoratif d'Aujourd'hui (1926) and Urbanisme (1925), in addition to publishing with Amédée Ozenfant the magazine L'Esprit Nouveau (1920-1925).[59]​ In his 1923 book he presented his theoretical principles in a series of texts with a somewhat provocative tone, with the aim of opening "eyes that do not see" towards modern architecture. It uses a concise style, with short and simple sentences, to establish clear premises that serve as a guide for the architect, with poetic similes and abundant graphic material. The content focuses on the aesthetic reform of architecture produced since the middle of the century, as well as concepts such as functionalism and industrial design; It speaks of the hygienic and moral qualities of architecture, which symbolizes on an ocean liner: "a pure, clean, clear, neat and healthy architecture." However, he believes that the styles are "a lie", although he recognizes the artistic nature of architecture, since beyond the simple rational function the architect configures an aesthetic to the building. Regarding his treatise on urban planning, he analyzes it from a functional perspective, in which the city is a work tool, and defends general lines based on order and linearity, which will be specified in the Charter of Athens (1943).[60]​.

Critics and art historians such as Henry-Russell Hitchcock, Siegfried Giedion and Nikolaus Pevsner also made their contribution to the theoretical corpus of the movement. Hitchcock made his first contribution to the International Style in an article in the magazine Hound and Horn in 1928, which was followed by the book Modern Architecture, Romanticism and Reintegration (1929), where he stated that the new style was "a distinct branch of modern architecture influenced by cubist and neoplasticist painting." But his most relevant work was The International Style: Architecture since 1922, prepared with Philip Johnson for the 1932 MoMA exhibition.[61]​ In it they established the defining parameters of the movement, noting that:.

The book about the exhibition contains a short text and abundant illustrations. It was written entirely by Hitchcock, as Johnson's participation consisted only of its correction. His thesis focuses on the confirmation of a new contemporary architectural style at the date of the exhibition, with Gropius, Oud, Le Corbusier, Mies van der Rohe, Rietveld and Mendelsohn as main representatives. He establishes the beginnings of this style after the First World War and points out as antecedents architects such as Peter Behrens, Otto Wagner, Auguste Perret and Frank Lloyd Wright, whom he describes as "semi-modern".[63]

Giedion presented his ideas preferably in Space, Time and Architecture. The Growth of a New Tradition (1941), which marked the historical image of modern architecture in Europe and the United States. It is a compendium of the classes Charles Eliot Norton Lectures that he gave at Harvard University between 1938 and 1939. Giedion's main objective was to integrate modern architecture into the history of art, as well as to establish its theoretical bases in a scientific context. He pointed out modern art and architecture as interdependent units and considered the contrast between science and art to be overcome. Just as Hitchcock established the aesthetic principles of rationalism, Giedion also sought to establish its structural principles, analyzing the formal qualities of the movement to find the underlying ideas. It marks the birth of modern architecture in industrialization and advances in engineering, and as pioneers Victor Horta, Hendrik Petrus Berlage, Otto Wagner, Auguste Perret and the Chicago School "Chicago School (architecture)"). It recognizes a fundamental role for Frank Lloyd Wright, but reserves the role of "heroes" of modern architecture for Gropius and Le Corbusier—Mies van der Rohe did not mention it until a reissue in 1954. Giedion's work was the basic manual of modern architecture until practically the 1980s and marked the conscience of two generations of architects.[64]​.

Pevsner was a German historian and critic established in the United Kingdom since 1935. In Pioneers of the Modern Movement (1936, later titled The Sources of Modern Architecture and Design), he introduced the term "Modern Movement", which he considered the "appropriate" style for the century, a functional style that responds to the new needs of the masses. Pevsner advocated a strict, anonymous, impersonal internationalism that leaves "less room for self-expression" and adapts to the new "basic social conditions." Throughout his literary production he developed a history of global, social and cultural architecture, unrelated to personalities and focused on the notion of style, with the intention of differentiating "true styles" from "transitory fashions".[65]

Other books on the Modern Movement were: Internationale neue baukunst by Ludwig Hilberseimer (1926), Die Baukunst der neuesten Zeit by Gustav Adolf Platz") (1927), Moderne Architektur und Tradition by Peter Meyer") (1928), Die neue Baukunst in Europa und Amerika by Bruno Taut (1929), Les tendances de l'architecture contemporaine by Myron Malkiel-Jirmounsky") (1930), The New World Architecture by Sheldon Cheney") (1930), La nuova architettura by Fillia") (pseudonym of Luigi Colombo, 1931), Gli elementi dell'architettura razionale by Alberto Sartoris (1932), etc. It is also worth highlighting the magazines that They spread the new style, such as Die Form, Das neue Frankfurt, L'architecture d'aujourd'hui, La Casa bella, Moderne Bauformen, Wasmuth Monatshefte für Baukunst und Städtebau and The Architectural Review.[66]​.

The first critical voices towards the modern Movement emerged from brutalism in the 1950s and developed in the 1960s with the work of historians and critics such as Reyner Banham and Manfredo Tafuri. Banham was a student of Giedion and Pevsner and, for his doctoral thesis, he was invited by the latter to analyze the Modern Movement from where he had left off, from the pioneers who laid the foundations of this style between the end of the century and the beginning of the . Banham carried out this exercise (Theorie and Design in the First Machine Age, 1960), but he did so from a critical, demystifying perspective; Comparing modern theories with practical implementations to check whether they actually fulfilled the espoused premises, it became evident, however, that in most cases the supposed functionalism defended by rationalist architecture was instead translated into a certain formalism. Faced with this, he advocated a "second age" dominated by the machine and mass consumption, and became the main defender of the style inherited from rationalism: brutalism.[67] Tafuri, a disciple of Giulio Carlo Argan and influenced by Marxism, structuralism "Structuralism (philosophy)," semiology and psychoanalysis, conceived architecture as a part of the history of work, of the mechanisms of production. In Teorie e storia dell'architettura (1968) he criticizes the optimism of avant-garde architecture and offers a more pessimistic vision, in which architecture is an ambiguous and changing process, "a perpetual contestation of the present." Also in Progetto e utopia (1973) he again criticizes modern architecture and points out the need to "destroy the powerful and ineffective myths that still fascinate architects."[68]​.

The architecture of the beginning of the century was born with a disruptive desire with respect to the past, especially in opposition to the historicism that had been practiced since the middle of the century, an academic style based on classical premises and the reinterpretation of styles from the past: neo-Romanesque, neo-Gothic, neo-baroque, etc. A first influence of the new movement was that of modernism "Modernism (art)") —known as art nouveau in France, Modern Style in the United Kingdom, Jugendstil in Germany or Sezession in Austria—, a style that sought to renew the architectural language and that provided some of the initial premises of the Modern Movement, although its excessive decorativeness was rejected by the rationalists. The artistic avant-gardes prior to the First World War, such as expressionism and futurism, were nourished by this style, movements that have sometimes been described as pre-rationalism. After the world war ended and until the mid-1920s, movements such as neoplasticism (De Stijl), the expressionism of the New Objectivity or constructivism "Constructivism (art)") evolved from those initial premises towards a greater formalism that already pointed to the International Style, which was forged in the Bauhaus School and in the founding in 1928 of the CIAM (International Congress of Modern Architecture).[69]​.

It is worth noting firstly as an immediate antecedent of rationalism the new architecture practiced in the century based on the technological advances brought about by the Industrial Revolution, which were reflected in various typologies such as architecture in iron or glass and iron. It should be taken into account that the new industrial era brought with it new problems and approaches in the construction and urban planning fields, since technical, economic and social progress led to the appearance of new needs such as railway stations, bridges and viaducts for new means of transport, changes in cities due to demographic increases that demanded new infrastructures and a whole series of new needs that architecture and engineering had to address.[70] These needs led to a faster and more efficient type of construction. cheap, with more daring solutions and far from academic architecture. A good example were the cast iron constructions, developed by architects and engineers such as Hector Horeau, Henri Labrouste, William Fairbairn") and James Bogardus. A driving factor of this new type of architecture were the trade fairs known as Universal Exhibitions, which due to their ephemeral nature promoted a type of construction of modular forms using prefabricated elements. The first, the Great Exhibition of London of 1851, stood out for the building The Crystal Palace, by Joseph Paxton, made of glass with a metal structure. The paradigm of this type of construction was the Eiffel Tower, built by the engineer Gustave Eiffel for the Paris World's Fair "Exposition Universelle de Paris (1889)") in 1889.[71]​.

Throughout the century, a new way of conceiving design and construction was developed, based strictly on reason and scientific criteria, which subordinated the form of the building to its function: functionalism "Functionalism (architecture)"), also called "architectural or structural rationalism." For this new generation of architects, their main tool was applied mathematics and their fundamental objective was the calculation of the lines of force in the structure of a building. Among its main representatives are: Jean-Nicolas-Louis Durand, Henri Labrouste, Gottfried Semper, Augustus Pugin, Eugène-Emmanuel Viollet-le-Duc, Anatole de Baudot and Hendrik Petrus Berlage.[72]​.

Another influence on modern architecture was that of William Morris and the Arts & Crafts movement, which emerged in the United Kingdom around 1860 and lasted until 1910. This movement defended a revaluation of artisanal work and advocated a return to traditional forms of manufacturing; It stipulated that art should be as useful as it is beautiful, with an ideal of beauty based on purity and simplicity. The greatest architectural exponent of this movement was the Red House, Morris's own house, built in 1859 by Philip Webb in Bexley Heath (Kent), made of red brick with a fluid design, without prominent facades, using traditional techniques; Morris designed the garden and the decoration was carried out by Morris, Webb and the Pre-Raphaelite artists Dante Gabriel Rossetti and Edward Burne-Jones, in a set that was cataloged as a "complete work of art." Other architects of this movement such as Charles Rennie Mackintosh, Arthur Heygate Mackmurdo and Charles Francis Annesley Voysey have just laid down its programmatic foundations: design subject to function, prevalence of vernacular styles and native materials, freedom of style and integration of the building into the landscape.[73]​.

Another of the precedents of rationalism was the so-called Chicago School "Chicago School (architecture)"), developed in the American city of Chicago between 1875 and 1900, and which stood out for being the promoter of a new type of building: the skyscraper. At that time, the city was growing at a dizzying pace thanks to its thriving economy, so construction had to be fast, which is why architects adopted iron engineering techniques. On the other hand, the speculative process of buildable land forced people to build in height to make the investment profitable—a fact brought about by the invention of the elevator in 1853. Thus, a series of large functional style buildings appeared built by architects such as William Le Baron Jenney, Daniel Burnham, John Wellborn Root, William Holabird, Martin Roche, Dankmar Adler and Louis Sullivan.[74] The latter coined the famous phrase "form follows function", the main aphorism of functionalism.[75]​.

The Austrian Sezession, the local variant of modernism, also initiated a path towards rationalism—especially Germanic rationalism. Although international modernism was a renewing movement and opposed to academic historicism, which supported comprehensive design and the use of new materials and technologies, its excessive decorativeness distanced it from the postulates of rationalism; However, the Austrian variant - like the Scottish one represented by the Glasgow School - had a more geometric and rectilinear component that did influence the appearance of Germanic rationalism.[76] Its first exponent was Otto Wagner, a professor at the Vienna Academy who instilled in his students modernity as a starting point for artistic creation, and who was interested in the use of new materials and urban planning approaches in line with new times, such as It can be seen in his renovation of Vienna's Karlsplatz or his metropolitan project with overpasses and stations of modern design. Joseph Maria Olbrich (Sezession building in Vienna, 1898) and Josef Hoffmann (Stoclet Palace in Brussels, 1905-1911) followed in their footsteps.[77] In 1903, Hoffmann and Koloman Moser founded the Wiener Werkstätte (Viennese Workshops), an association close to the Arts & Crafts movement that aimed to bring industry closer to the world of art. applied arts.[78]​.

In the field of urban planning, the theories of Ebenezer Howard and his idea of ​​a garden city were essential for the rationalist proposals, a type of urban entity of residential areas separated by large green areas and connected by large radial avenues, with a nerve center that would bring together buildings for administration, finance, services, education, health, culture and other sectors.[79]​.

Finally, it is worth remembering the work of several architects who, in reaction to the excessive decorativeness of art nouveau, developed in the first decade of the century a more sober style based on classical forms but without falling into the ossified language of academic neoclassicism, but with modern solutions that largely pointed to rationalism. This style is sometimes defined as "modern classicism" or "primitive rationalism" and its greatest representatives were: Tony Garnier "Tony Garnier (architect)"), Auguste Perret, Adolf Loos and Peter Behrens.[80] The first was an architect and urban planner, the first to propose a global model of an industrial city (Une Cité Industrielle, 1917) in which life and technology are combined, with a deep study of the functions urban areas and the adaptation of each element to its function. Most of his works are in Lyon: market and slaughterhouse (1908-1924), Grange Blanche Hospital (1911-1927), Municipal Stadium (1913-1918), United States neighborhood (1920-1935). Franklin in Paris (1903), Ponthieu Street garage (1905), Notre-Dame church in Le Raincy (1922-1923).[81] Loos was initially influenced by Otto Wagner's secessionism, but he distanced himself from it due to his fear of being constrained in a style of marked guidelines and excessive originality, in search of greater simplicity away from any ornamentation. He took from the Arts & Crafts movement his commitment to craftsmanship and a more human component in the construction process.[82]​ Among his works, the following stand out: the residential building on Michaelerplatz in Vienna (1909-1911) and the Steiner (1910) and Scheu (1912) houses, also in Vienna.[83]​ Behrens opted for an architecture of simple, austere and functional lines, with the use of new materials and technologies, with some influence of William Morris. Director of the General Electricity Company AEG of Berlin, he built a series of factories and buildings for it where he anticipated numerous of the structural solutions of rationalism, among which the turbine hall (1909) stands out.[82]​.

Expressionism

Expressionism was a cultural movement that emerged in Germany at the beginning of the century, which was reflected in a large number of fields: plastic arts, architecture, literature, music, cinema, theater, dance, photography, etc. Expressionist architecture developed mainly in Germany, the Netherlands, Austria, Czechoslovakia and Denmark. It was characterized by the use of new materials, sometimes provoked by the use of biomorphic forms or by the expansion of possibilities offered by the mass manufacturing of construction materials such as brick, steel or glass. Many expressionist architects fought in the First World War and their experience, combined with the political and social changes resulting from the German Revolution of 1918, led to utopian perspectives and a romantic socialist program. Strongly experimental in nature, the expressionists' works stand out for their monumentality, the use of brick and subjective composition, which gives their works a certain air of eccentricity. The main expressionist architects were: Bruno Taut, Walter Gropius, Erich Mendelsohn, Hans Poelzig, Hermann Finsterlin, Fritz Höger and Hans Scharoun.[84]​.

Expressionist architecture developed in Germany in various groups, such as Deutscher Werkbund, Arbeitsrat für Kunst, Novembergruppe and Der Ring; The Amsterdam School is also worth highlighting in the Netherlands. The Deutscher Werkbund (German Labor Federation) was founded in Munich in 1907 by Hermann Muthesius, Friedrich Naumann and Karl Schmidt, and later incorporated figures such as Walter Gropius, Bruno Taut, Hans Poelzig, Theodor Fischer, Wilhelm Kreis, Richard Riemerschmid and Bruno Paul. Heir to Jugendstil and Sezession, and inspired by the Arts and Crafts movement, its objective was the integration of architecture, industry and crafts through professional work, education and advertising, as well as introducing architectural design into modernity and giving it an industrial character. The main characteristics of the movement were the use of new materials such as glass and steel, the importance of industrial design and decorative functionalism.[85] This group was the one that organized an exhibition in Stuttgart in 1927 for which they built a large housing colony, the Weißenhofsiedlung, with a design by Mies van der Rohe and buildings built by Gropius, Behrens, Poelzig, Taut and others, together with outside architects. from Germany as J.J.P. Oud, Le Corbusier and Victor Bourgeois. This exhibition was one of the starting points of the new architectural style that was beginning to emerge.[86]​.

Parallel to the German Deutscher Werkbund, between 1915 and 1930 a notable architectural school of an expressionist nature developed in Amsterdam (Netherlands). Influenced by modernism - mainly Henry Van de Velde - and by Hendrik Petrus Berlage, they were inspired by natural forms, with buildings of imaginative design where the use of brick and concrete predominates. Its main members were Michel de Klerk, Piet Kramer and Johan van der Mey, who worked together countless times, contributing greatly to the urban development of Amsterdam, with an organic style inspired by traditional Dutch architecture, in which undulating surfaces stand out.[87]​.

The Arbeitsrat für Kunst (Council of Art Workers) was founded in 1918 in Berlin by the architect Bruno Taut and the critic Adolf Behne. Emerged after the end of the First World War, its objective was the creation of a group of artists who could influence the new German government, with a view to the regeneration of national architecture, with a clear utopian component. Their works stand out for the use of glass and steel, as well as for the imaginative and loaded with intense mysticism. They soon recruited members from the Deutscher Werkbund, such as Walter Gropius, Erich Mendelsohn, Otto Bartning and Ludwig Hilberseimer. After the events of January 1919 related to the Spartacist League, the group renounced its political goals and dedicated itself to organizing exhibitions. Taut resigned as president and was replaced by Gropius, although the group eventually dissolved. 1921.[88] Linked to this was the group Novembergruppe, which emerged in 1918 and was active until 1933, with the aim of using art and architecture to improve the world. Walter Gropius, Hugo Häring, Erich Mendelsohn and Ludwig Mies van der Rohe were among its members.[89]​.

The group Der Ring (The Circle) was founded in Berlin in 1923 by Bruno Taut, Ludwig Mies van der Rohe, Peter Behrens, Erich Mendelsohn, Otto Bartning, Hugo Häring and several other architects, to whom Walter Gropius, Ludwig Hilberseimer, Hans Scharoun, Ernst May, Hans and Wassili Luckhardt, Adolf Meyer "Adolf Meyer (architect)"), Martin Wagner "Martin Wagner (architect)"), etc. Its objective was, as in previous movements, to renew the architecture of its time, with a special emphasis on social and urban aspects, as well as research into new materials and construction techniques. Between 1926 and 1930 they carried out a notable work of construction of social housing in Berlin, with houses that stand out for their use of natural light and their location in green areas, among which the Hufeisensiedlung (Horseshoe Colony, 1925-1930), by Taut and Wagner, stands out. Der Ring disappeared in 1933 after the advent of Nazism.[90]​.

The last phase of German expressionism was the so-called Neue Sachlichkeit (New Objectivity), a mostly pictorial movement that had a translation to architecture based on a rational and objective conception of it, as well as on the social commitment of the architect.[91] This movement took shape in the association Neues Bauen (New Construction), which included Bruno Taut, Erich Mendelsohn and Hans Poelzig.[92]​.

Cubism

Cubism (1907-1914) was an artistic movement based on the deformation of reality through the destruction of the spatial perspective of Renaissance origin and, in its place, the organization of space according to a geometric plot and a simultaneous vision of objects. Although it occurred essentially in the plastic arts, it had some manifestation in the field of architecture, especially in Czechoslovakia.[93] Its main representative was Josef Gočár, who after initially being influenced by the work of Josef Hoffmann, in 1911 joined the Group of Plastic Artists (Skupina Výtvarných Umělců) and began to work in the cubist style, as denoted in the House of the Black Madonna in Prague (1911–1912) and the thermal establishment of Lázně Bohdaneč (1912-1913), where he combined classical and modern forms with pyramidal cubism. After the First World War and the independence of Czechoslovakia, he began with Pavel Janák the search for a Czech national architectural style, which was reflected in the so-called "rondocubism", which incorporates rounded and multicolored shapes from vernacular Bohemian-Moravian decoration, as evidenced by his Legion Bench in Prague (1921-1922). Since 1923 his style evolved towards a functionalism of neoplasticist influence.[94]​.

Other representatives were: Pavel Janák (Jakubec villa in Jičín, 1911-1912; Drechsel villa in Pelhřimov, 1912-1913; Pardubice crematorium, 1921-1923; Adria palace in Prague, 1922-1925);[95] Josef Chochol (Kovařovic villa in Prague, 1912-1913; Bayer and Hodek residential buildings in Prague, 1913-1914);

Futurism

Futurism (1909-1930) was an Italian artistic movement that exalted the values ​​of the technical and industrial progress of the century, which highlighted aspects of reality such as movement, speed and simultaneity of action. Although it occurred especially in the plastic arts, it also had some approach in architecture, although the utopian nature of its formulations prevented its material realization in many cases. The figure of Antonio Sant'Elia stood out, who in 1914 presented his model of a futuristic city, characterized by tall skyscrapers, streets at different levels and new typologies of buildings, such as stations and power plants. In 1914 he signed the Manifesto of Futurist Architecture, where he proclaimed that architecture "must be preserved as art, that is, as synthesis, as expression."[99] Sant'Elia was joined by the architect Mario Chiattone and together they exhibited drawings of their dreamed city of the future, the Città nuova (new city). Died in 1916, Sant'Elia was unable to carry out his projects, but his theoretical work influenced the construction of Giacomo Mattè-Trucco's FIAT workshops in Turin (1915-1921), with flat concrete roofs where cars ran on top of the workshops.[100]​.

Neoplasticism (De Stijl)

Neoplasticism (1917-1932), also known by the Dutch name De Stijl ("the style"), was also an interdisciplinary movement that stood out in painting with figures such as Piet Mondrian and Theo van Doesburg, in an abstract style, while in architecture a style was developed marked by geometric compositions and objective and innovative solutions, with great influence from the work of Hendrik Petrus Berlage. They are works that stand out for smooth surfaces and decomposition into planes, vertical and horizontal lines, with the use of color as an emphasizing element of the structure, generally primary and flat colors.[101] Some of their stylistic hallmarks, such as flat ceilings, smooth walls and free and flexible interior spaces were later characteristic of the International Style.[102]​.

The most paradigmatic work of this style was the Rietveld Schröder House in Utrecht (1924), by Gerrit Rietveld and Truus Schröder, whose structural solutions largely pointed out the main characteristics of the International Style: asymmetrical composition, geometric shapes without relief, flat roofs with overhangs in the corners, absence of ornamentation, longitudinal windows and preference for the color white. This new way of understanding architecture translated into transparent volumes, without load-bearing walls or monumental openings, which gave the buildings an appearance of spaciousness and incorporeality that would be the most attractive image of rationalism.[103] Within a three-dimensional grid, the volumetric composition is based on translations and superpositions of planes, with a fluid sequence of spaces that favors the multiplicity of functions.[104]​.

A variant of neoplasticism was elementarism, a movement founded in 1924 by Theo van Doesburg. In contrast to the primary colors and right angles favored by De Stijl, Van Doesburg introduced greater dynamism through diagonals and rotations, described by this artist as "countercompositions", which marked his break with Piet Mondrian. Although it began in painting, this style was also transferred to architecture, in which the constructivist and Bauhausian influence was noted. Van Doesburg aimed to make a synthesis between the arts and facilitate a practical application of artistic creation in everyday life. In 1924, Van Doesburg and Cornelis van Eesteren published Towards a collective construction, where they declared that "painting, without architectural construction, has no reason to exist." They developed their aesthetics in the Manifesto of Elementarism (1926), in which they defended the contrast of the diagonal in paintings and sculptures with the vertical-horizontal linearity of architecture, as they put into practice in the decoration of the Café L'Aubette in Strasbourg (1928-1929), carried out by Van Doesburg in collaboration with Hans Arp and Sophie Taeuber-Arp.[105]​.

Constructivism

Constructivism "Constructivism (art)") (1914-1930) was a movement that emerged in revolutionary Russia, a politically committed style that sought through art to carry out a transformation of society through a reflection on pure artistic forms conceived from aspects such as space and time, which generated in the plastic arts a series of works in an abstract style, with a tendency towards geometrization. In its architectural aspect, it began a program linked to the revolution that sought a functional architecture that satisfied the real needs of the population.[106]​ Constructivism coincided with neoplasticism in the search for an art of collective utility based on objective aesthetic principles.[107]​ The end of the movement occurred in 1932 with the suppression of artistic groups carried out by the Stalinist dictatorship.[108]​.

Halfway between architecture and sculpture is the Monument to the Third International by Vladimir Tatlin (1919-1920), of which he only made the model. It would have consisted of a structure 395 meters high, with a stepped spiral shape that symbolized the progress of socialism, with floors that would rotate at different time intervals: daily, monthly and yearly.[109] According to Tatlin, the monument represented the "union of purely artistic forms (painting, sculpture and architecture) for a utilitarian purpose."[110]

Like this one, many other projects of the time were not carried out due to the precariousness of the country's political situation, such as the largely utopian postulates of El Lissitzky, which brought together some of the premises of constructivism, neoplasticism and the Bauhaus. Among them are his Proun spaces, which anticipated the environments of the later installation art "Installation (art)"), or his "cloudstand" buildings (1925), horizontal skyscrapers supported by large tower-shaped pillars.[111]​.

The most practical achievements were carried out by two associations: the ASNOVA (Association of New Architects), created in 1923 under the premise of finding universal solutions for architecture, detached from the relationships between form-function or form-social context, and represented fundamentally by Konstantin Melnikov, author of the Moscow Workers' Club (1925-1927) and the Russian pavilion at the Paris Exhibition of Decorative Arts in 1925, and by Nikolai Ladovski, author of the Lenin Institute in Moscow (1927); and the OSA (Union of Contemporary Architects), founded in 1925 with the aim of combining artistic and political avant-garde and creating a productive and utilitarian art, represented by the brothers Aleksandr, Leonid and Víktor Vesnín (Moscow Labor Palace, Pravda building in Leningrad, Lenin Institute in Moscow) and by Iván Nikolayev.[112] It is also worth highlighting the promotion of Russian constructivism the work of Vkhutemás (acronym for Higher Education Workshops in Art and Technology), a state art and technical school located in Moscow that promoted the avant-garde in art and architecture.[113]​.

Organicism: Frank Lloyd Wright

Frank Lloyd Wright was an American architect, a precursor of organic architecture and initiator of the Prairie School movement. In his work, certain coincidences with rationalism are perceived, such as the use of terraces and perpendicular forms, but from an organicist approach, that is, adapted to nature: architectural forms merge with natural ones in an integrated and harmonious whole, as in his famous Kaufmann house, better known as Casa de la Cascade (in English Fallingwater, 1936-1939).[115]

Wright initially worked in Louis Sullivan's studio for six years and inherited from his teacher the idea that American architecture should be renewed. Even so, he thought that the basis of this renewal was in the traditional American way of life and in the integration of man with nature achieved by the pioneers of the American West. Thus, Wright's construction ideal was the single-family house with horizontal spaces, large ceilings and a perfect interrelation with the environment, as in the Waterfall House, which is part of the surrounding landscape. He thus created the typology of prairie houses, of which he built quite a few for businessmen and magnates, as well as his own residence, Taliesin West, in Scottsdale "Scottsdale (Arizona)"), Arizona (1938).[116]

For Wright, architecture had to encompass both the construction itself and its adaptation to its environment; in his words: "an architecture that develops from the inside out, in harmony with the conditions of its being", as well as that "in organic architecture, then, it is totally impossible to have the building as one thing, its furniture as another, and its position and its environment as another."[117] Wright adopted the idea of ​​"total design" from the English Arts & Crafts movement, so in his works he designed both the exterior and the interior of the houses, with a type of furniture that was equally organic in conception. Other notable Prairie School architects were William Gray Purcell and George Grant Elmslie.[118]

The Bauhaus

The Bauhaus School is usually considered the first exponent of a fully mature rationalism. The Staatliche Bauhaus (State Building House) was born in 1919, when the architect Walter Gropius assumed the direction of the Weimar School of Arts and Crafts, which he reoriented towards a multidisciplinary study program that addressed both architecture and design and the decorative arts: the school's students learned theories of form and design, as well as workshops in stone, wood, metal, clay, glass, weaving and painting. The Bauhaus moved to Dessau in 1925 and to Berlin in 1932. Gropius was succeeded by Hannes Meyer in 1928, and he was succeeded by Ludwig Mies van der Rohe in 1930. The school was closed by the center's management in 1933 due to the systematic harassment to which they were subjected by the Nazi authorities.[119]​.

The Bauhaus teaching program was based on the correlation between all creative processes, with the aim of unifying art and design. According to Gropius, "the ultimate goal of the Bauhaus is the collective work of art, in which there are no barriers between the structural arts and the decorative arts." Thus, architects, artists and craftsmen would work together in the construction of the "building of the future."[120] At first the Bauhaus was influenced by the Viennese Sezession and the Wiener Werkstätte, as well as William Morris and the Arts & Crafts movement, by Peter Behrens and Henry Van de Velde, in addition to the expressionism that was fashionable in Germany at the time. However, since 1922 the influence of the Dutch group De Stijl was noticeable and the school became more austere and functionalist, and more focused on industrial design.[120] Again according to Gropius, "we want an architecture adapted to our world of machines, radios and cars with fast engines, an architecture whose function is clearly identifiable by the relationship of its forms."[121]​.

Four phases are distinguished in the history of this school: the first (1919-1924) corresponds to its stay in Weimar and the architectural formulations proposed are still the survival of the expressionist style, with a certain utopian component; With hardly any material achievements, the most relevant project outlined at this stage is Gropius's project for the headquarters of the Chicago Tribune (1922, not carried out), as well as that of an International Philosophical Center in Erlangen (1923-1924), also not carried out. The second stage (1925-1930) began with the move to Dessau, where the school headquarters building was built, the work of Gropius. The school's line is already fully rationalist, with a clear commitment to design and industrial production. The main architectural characteristics of these years are the geometric planimetries, the orthogonal layout, the use of glass curtain walls and horizontal windows, as seen in the projects for "large-scale construction houses" (1924), the teachers' housing (1925-1926) or the Törten Colony in Dessau (1926). During the direction of Hannes Meyer (1928-1930) there was a greater connection with the political left and there was a commitment to an architecture that served the needs of the population, more practical and far from pure forms, which denotes the influence of Russian constructivism. Meyer's main works were the project for the palace of the League of Nations in Geneva (1926-1927) and the School of Trade Unions in Berlin (1928-1930). After Mies van der Rohe (1930-1933) took over the leadership, the school moved towards a conception of architecture more focused on structural issues, with some influence from the Dutch group De Stijl and the Russian architect and artist El Lissitzky. Among Mies' works in these years, the following stand out: the German Pavilion "German Pavilion (Barcelona)") for the Barcelona International Exhibition (1929) "Barcelona International Exhibition (1929)"), the Tugendhat house in Brno (1930) and the Lemcke house in Berlin (1932).[122]​.

In 1923, the Bauhaus organized an exhibition entitled Art and technology: a new unit, in which the Experimental House or Haus am Horn, by Georg Muche and Adolf Meyer "Adolf Meyer (architect)") was presented, a prototype of a functional housing mass-produced and built in steel and concrete, completely decorated with objects and furniture designed by Marcel Breuer.[123] In 1927 the architecture department was established, until then non-existent despite to the school's multidisciplinary approach, led by Hannes Meyer and, in 1928, an urban planning department, led by Ludwig Hilberseimer.[124]

Probably the most notable architectural achievement of this school is the Bauhaus building in Dessau, designed by Gropius in 1925. He created it with strict criteria of functionality, which is why it became an icon of rationalist architecture. The building was made up of two bodies, one rectangular with classrooms and laboratories and another L-shaped with an auditorium, stage, kitchen and dining room, five stories high that housed rooms for students, bathrooms and a gym. Both buildings were connected by a two-story high skybridge, which housed the administration offices. He mainly used concrete and glass as materials, with extensive use of the curtain wall.[125]​.

France

As seen in the background, the pioneers of pre-rationalism in France were Tony Garnier and Auguste Perret. The general lines of later French rationalism were based on most of the premises of the International Style, although with less interest in functionality than in German rationalism. Corbusier, Gropius, Victor Bourgeois and Willem Marinus Dudok; in 1932, André Lurçat and Alberto Sartoris. This association promoted various exhibitions and, in 1934, published the manifesto Pour l'art moderne, cadre de la vie contemporaine, which defended modern architecture. by André Bloc, which served as an organ of dissemination of the new architecture.[127]​.

The main reference of French rationalist architecture was Le Corbusier, pseudonym of Charles-Édouard Jeanneret-Gris. Although Swiss by birth, he settled in Paris in 1917 (at the age of thirty) and became a French citizen in 1930. He was an engraver, designer, painter, sculptor and writer, although, paradoxically, the person who most influenced the architecture of the century did not qualify as an architect.[128] In his beginnings he was influenced by Tony Garnier and Auguste Perret, as evidenced by his use of reinforced concrete. Le Corbusier represents a classicist rationalism, which has its roots in Greco-Roman architecture; According to him, his only teacher had been History. For him, «architecture is the wise, correct and magnificent play of volumes assembled under light. Cubes, cones, spheres, cylinders or pyramids are the large primary shapes that light reveals well. It is the essential condition of the plastic arts."[129]​.

Among his first formulations is the Maison Domino (1914), a typical house designed as an elementary housing cell to be produced in series and allowing the layout of free floor plans, formed by a concrete structure supported on six uprights of cantilever beams. It would serve as a minimum cell to build blocks of flats that he would call immeuble-villas ("city-buildings"), as materialized in his villa Besnus de Vaucresson in 1922.[131]​.

In its beginnings it was linked to purism, a variant of synthetic cubism "Cubism") led together with Jeanneret by Amédée Ozenfant. They admired the beauty and purity of machines, which was their main inspiration along with mathematics, with the desire to integrate architecture, painting and design, concepts that they developed in the magazine L'Esprit Nouveau (1920-1925) and in the book Vers une architecture (1923), as well as in the L'Esprit Nouveau pavilion for the Paris Decorative Arts Exhibition of 1925. In In 1922 he partnered with his cousin, the engineer Pierre Jeanneret, with whom he opened a studio in Paris and, from 1927, he collaborated with Charlotte Perriand on furniture design.[132]​.

Just as Mies van der Rohe preferentially used steel and glass and Le Corbusier used reinforced concrete, both nevertheless achieved free and open structural solutions, which would be the main stylistic hallmark of their work. Another of its characteristics would be the use of , concrete pillars that allowed the building to be supported on an empty space, which accentuated the sensation of volume as opposed to mass.[133] In 1926 he published his , in which he recounted his main architectural proposals: the ground floor on , the open floor, the free façade, the longitudinal window (). and the terrace-garden.[134] Another of his approaches was the ("architectural promenade"), the sequential relationship of spaces between the interior and exterior of a building, which he developed for the first time in the Jeanneret and La Roche villas in Paris (1923).[135] He applied all these principles in the Stein villa in Garches (1927) and, especially, in the Savoye villa in Poissy (1928-1930), one of the most successful examples of rationalist architecture, formed by a square-shaped floor raised from the ground by a series of , with an open plan, elongated horizontal windows and a flat roof on which a terrace-garden is located; It has no façade, no front or back, but is a complex that cannot be grasped from a single point of view.[136] In 1927 he built a version of his Maison Citrohan for the Weißenhofsiedlung in Stuttgart, for which he also built another double-dwelling building.[137] In these years he also developed the unrealized projects for the palace of the League of Nations in Geneva (1927), the World Museum for the Mundaneum in Geneva (1929) and the Palace of the Soviets in Moscow (1931).[136] Between 1929 and 1933 he built the Cité de Refuge in Paris for the Salvation Army, a building inspired by nautical design, and between 1931 and 1933, the Swiss Pavilion for the International University City of Paris.[138]

Germany

In Germany, as has been seen, rationalist architecture was closely linked in its beginnings to expressionism and the various group manifestations that emerged within it, such as Deutscher Werkbund, Arbeitsrat für Kunst and Der Ring, as well as the Bauhaus School, the first in which a fully mature rationalist style was achieved. In the development of German rationalism, it is worth highlighting the Weißenhofsiedlung development, built in Stuttgart in 1927 as an exhibition organized by the Deutscher Werkbund with the aim of promoting low-cost housing, supervised by Ludwig Mies van der Rohe and in which German architects such as Peter Behrens, Richard Döcker, Walter Gropius, Ludwig Hilberseimer, Hans Poelzig, Adolf participated Rading, Hans Scharoun, Adolf Gustav Schneck, Ferdinand Kramer, Bruno Taut and Max Taut, along with others from other countries, such as Victor Bourgeois, Le Corbusier, Pierre Jeanneret, Josef Frank, J.J.P. Oud and Mart Stam. Thirty-one homes were built, designed under premises of visual unity based on white plaster walls, rectangular shapes, flat roofs and horizontal bands of windows.[18]​.

The two main representatives of German rationalism—and world leaders—were Walter Gropius and Ludwig Mies van der Rohe. Gropius was an architect, urban planner and designer, a disciple of Peter Behrens. In his beginnings he was part of the expressionist movement, within which he was linked to the groups Deutscher Werkbund, Arbeitsrat für Kunst and Der Ring. In 1910 he opened his own studio, where he worked in association with Adolf Meyer "Adolf Meyer (architect)"). Among his first works stands out the Fagus Factory (1911-1914), in Alfeld, a rectangular building that stands out for the use of the curtain wall, which would be one of its main stylistic hallmarks. Municipal Theater of Jena.[152]​ In 1919 he founded the Bauhaus School, of which he built its headquarters in Dessau in 1925.[163]​ In 1928 he opened his own office, from which he developed the Dammerstock development in Karlsruhe (1928-1929),[165]​ as well as the Siemensstadt project in Berlin. (1929-1930).[166]​ With the rise to power of the Nazis he was forced to go into exile, first to the United Kingdom and then to the United States, where he was director of the Graduate School of Design at Harvard University (for his American work see here).[167]​.

In 1945 he teamed up with eight young architects in the firm The Architects' Collaborative (TAC). In addition to the works carried out by this studio in the United States, in the 1950s and 1960s he carried out some projects again on German soil: in 1957 he built with Wils Ebert") an apartment block in the Hansaviertel district in West Berlin; shortly after he created the new city of Britz-Buckow-Rudow; and in 1964 he designed the Bauhaus-Archiv building in Berlin, carried out after his death by Alexander Cvijanovic") in 1977.[167]​.

Austria and Switzerland

Austrian rationalist architecture was heir to the Viennese Sezession, through the mediation especially of Josef Hoffmann, a professor at the Kunstgewerbeschule who trained a new generation of architects. After the first post-war period, Hoffmann approached the postulates of rationalism, although with a somewhat more traditional language, as in his popular houses built between 1925 and 1930. In Vienna, a Werkbundsiedlung (exhibition of permanent and temporary buildings promoted by the Österreichischer Werkbund) was held in Vienna in 1932, which promoted a development of experimental housing in the Lainz district, in which thirty-one architects built seventy houses, the “largest exhibition of buildings in Europe” as it was announced at the time. The majority were Austrian architects, among whom Hoffmann himself, Adolf Loos, Walter Loos, Josef Frank, Richard Neutra, Clemens Holzmeister, Margarete Schütte-Lihotzky, Oskar Strnad, Walter Sobotka and Ernst Plischke stood out, as well as the German Hugo Häring, the French André Lurçat and Gabriel Guevrekian and the Dutch Gerrit Rietveld. The result was a set of white houses with an open floor plan and flat roofs, similar to the Weißenhofsiedlung in Stuttgart but somewhat more formalistic.[191] At the housing level, it is also worth highlighting the Karl Marx-Hof in Vienna, designed by Karl Ehn in 1927, a gigantic housing block one kilometer long, rectangular in shape with a large central courtyard that serves as a plaza, garden and community services center, with almost 1,400 apartments.[192]​.

Austrian rationalist architects include: Ernst Plischke, author in 1931 of the Liesing Employment Office in Vienna, considered the "first modern building in Austria"; (1932);[194]​ and Margarete Schütte-Lihotzky, the first woman to qualify as an architect in her country, participating in the construction of the Winarsky-Hof popular house in 1924 and designer of the famous Frankfurt kitchen, as well as equipment for children.[195]​.

Due to its proximity, Switzerland received the direct influence of German rationalism, but also of French rationalism, especially Le Corbusier, Swiss by birth. Although he developed his work in France, Le Corbusier left some samples of his work in his native country: the villas Jeanneret-Perret (1912) and Schwob (1916) in La Chaux-de-Fonds, the villa Le Lac in Corseaux (1923), the Clarté building in Geneva (1930-1932) and the Heidi Weber Museum in Zurich (1963-1967).[196]​.

The initial impulse of rationalism in Switzerland is due to Karl Moser, professor at the Federal Polytechnic School of Zurich who trained a generation of architects among whom were his son Werner Max Moser, the cousins Emil and Alfred Roth, Rudolf Steiger, Max Ernst Haefeli and Carl Hubacher. Many of them later worked in other countries: Werner Moser in the United States with Frank Lloyd Wright, Alfred Roth in Paris with Le Corbusier, Haefeli in Germany with Otto Bartning. In 1930, all of these architects (except Alfred Roth), together with Paul Artaria and Hans Schmidt, were commissioned to build the Neubühl neighborhood in Zurich, another example of popular collective housing like those developed in Germany, with a layout of single-family houses attached in a row.[197]​.

Netherlands and Belgium

Dutch rationalism was a direct heir to the neoplasticism of the De Stijl group. Like the French, he showed less interest in functionalism than the German. Works of notable quality were carried out in this country: according to Leonardo Benevolo, "after the crisis of the German movement, the main contributions to the progress of European modern architecture come from Holland."[209]​.

Jacobus Johannes Pieter Oud was appointed municipal architect of Rotterdam in 1918, a position from which he promoted the construction of low-cost houses in full International Style, most between 1925 and 1930, such as those in Kiefhoek (1925-1927). Those by Hoek van Holland (1924-1927) stand out, a group of white houses arranged in a row, with horizontal windows, metal doors and curved elements of nautical inspiration. In 1927 he built five houses for the Weißenhofsiedlung development in Stuttgart, small in size but with a very practical design and functional furniture. Oud's architecture is largely based on industrial techniques and the use of new materials.[210]​ Among his latest works are the building for Shell in The Hague (1939-1942) and the children's bio-recreation home in Arnhem (1952-1960).[211]​.

Gerrit Rietveld broke with De Stijl in 1928, the year in which he joined CIAM and began a more purely rationalist phase, as can be seen in his houses on Erasmuslaan Street in Utrecht (1930-1931), arranged in a row and rectangular in shape, stuccoed in white and with horizontal windows, in the purest International Style.[212] Other of his works were: the Vreeburg cinema in Utrecht (1936, with Truus Schröder), the Dutch pavilion for the 1954 Venice Biennale and the Van Gogh Museum in Amsterdam (1963-1972, with Joan van Dillen") and Johan van Tricht").[211]​.

Mart Stam was influenced by Mies van der Rohe and El Lissitzky. Two of his first works, the primary schools San Wendel (1924) and Thunn (1925) are already in full International Style. At the Weißenhofsiedlung in Stuttgart in 1927 he built three semi-detached houses forming a rectangular block. He later worked with Ernst May in Frankfurt, where his Budge Nursing Home (1929-1930) stands out, of which Hitchcock and Johnson noted that although it is "guided exclusively by economic and functional considerations, the building also undoubtedly has aesthetic value."[212] He worked with his wife Lotte Beese, a Bauhaus student and collaborator of Ernst May in the Soviet Union - where she met her husband; He was responsible for the neighborhoods of Pendrecht (1948-1952), Het Lage Land and Ommoord (1962-1969) in Rotterdam.[213]​.

Willem Marinus Dudok, an engineer by training, was appointed municipal engineer of Hilversum in 1915, a rapidly growing city of which he was in charge of regulating its general plan and the construction of several popular neighborhoods and public buildings, among which the City Hall (, 1924-1928) stands out.[214] He was also the author of the Dutch pavilion of the University City of Paris (1927), the department store building. De Bijenkorf in Rotterdam (1929) and the Utrecht Theater (1939-1941).[215]​.

United Kingdom and Ireland

Rationalism did not reach the United Kingdom until 1930, due mainly to the rejection of what was considered excessive Germanism in this movement.[228] Many of the rationalist works were built by immigrants from the continent who were escaping the Russian and German dictatorships. Among the British architects, Frederick Etchells stands out), translator into English of Towards a new architecture by Le Corbusier and author of the Crawfords Advertising Building in London (1929); (1929-1930), in Amersham, inspired by Arts & Crafts country houses but built in white concrete with a flat roof and horizontal windows, in the rationalist style; other works by Connell, in association with Basil Ward and Colin Lucas, were the New Farm house in Greyswood (Surrey, 1932), the houses of Parkwood Estate in Ruislip (London, 1935) and Frognal No. 66 in Hampstead "Hampstead (London)") (1938), of Lecorbusierian inspiration.[230]​.

Due to English reluctance towards modern architecture, the majority of constructions were houses for the middle class, but some low-cost homes were also built, such as Kent House in Chalk Fram (London, 1934), by Connell, Ward and Lucas, and Sassoon House in Camberwell (London, 1934), by Maxwell Fry[231]—Fry worked alongside his wife, Jane Drew, with whom he carried out important projects in India and Africa—.[232] Of higher category were the flats on Lawn Road in Hampstead (1933-1934), by Wells Coates, an engineer by profession and English representative at the CIAM through the Modern Architectural Research Group (MARS).[231] Coates was also the author of a country house in North Benfleet, Essex (1934-1936). It is also worth mentioning Francis Yorke, author of the Nast Hyde Villa in Hatfield "Hatfield (Hertfordshire)") (1935), and Owen Williams, author of the Boots pharmaceutical factory in Beeston (1930-1932), which stands out for its profuse use of the curtain wall and its tree-shaped concrete columns.[232]

One of the main exponents of British rationalism was the Russian Berthold Lubetkin, creator of the Tecton company (1932-1948).[note 3]​ One of his main achievements was the Highpoint I building in Highgate, London (1935).[36]​ It is a tall eight-story block in the shape of a double cross, of Lecorbusierian influence, supported on pilotis and surrounded by gardens, with a communal roof-terrace; Le Corbusier himself defined it as "the first vertical garden city of the future."[234] Other works of the Tecton seal were: the Finsbury health center (London, 1939), the houses on Genesta Road (London, 1934), Six Pillars on Crescent Wood Road (London, 1935) and Newton Road (London, 1938).[235] The signature of architects, together with the engineer Ove Arup, he was responsible for the gorilla cage and the penguin pool at the London Zoo (1932-1937), whose innovative design, close to constructivist sculpture, brought them notable success.[234]​.

Nordic countries

In general, the Nordic countries developed a regionalist variant of the International Style, due to the circumstances of their climate and the materials used, where the use of wood stands out.[240] The main exponent of Nordic architecture was the Finnish Alvar Aalto, halfway between rationalism and organicism. Faced with the excessive geometrization of orthodox rationalism, Aalto defended, like Frank Lloyd Wright, integration with nature, as well as the use of natural materials such as wood. While still a student at the Helsinki Polytechnic University he designed his parents' house in Alajärvi. Graduated in 1921, he worked for two years in the project office of the Göteborg Exhibition. In 1924 he married Aino Marsio, with whom he formed a professional couple. His first notable work was the Jyväskylä People's House (1924-1925), inspired by Florentine architecture.[241] Between 1927 and 1929 he built a standardized block of flats in Turku with prefabricated concrete elements reminiscent of the works of Mies and Gropius for the Weißenhofsiedlung. In 1929 he participated in the II CIAM, where his contact with Siegfried Giedion and with artists such as Constantin Brâncuși, Georges Braque and Fernand Léger brought him closer to the avant-garde. Between 1927 and 1929 he built the building for the Turun Sanomat newspaper, based on Le Corbusier's "five points for a new architecture." Another important work from its beginnings was the Viipuri public library (1927-1935), which shows its evolution from a certain classicism towards functionalism.[242]​.

Fame came to him with the Paimio Sanatorium (1929-1933), a work adapted to its natural environment for which he studied in depth the path of the sun to make the most of its impact on the building, so that the sick could enjoy maximum light and heat. In 1931 he settled in Helsinki, where he began to design industrially produced furniture; His foray into wood led him to also use this element in architecture, so his style evolved towards greater organicism. Among his works from these years are his house in Helsinki (1934-1936), a complex of houses for workers and a pulp factory in Sunila") (1935-1939) and the Villa Mairea in Noormarkku (1938-1941), which shows his transition towards an organicism of rural influence, which has been described as a "romantic modern movement".[243] In 1937, a exhibition of his works and, in 1939, he built the Finnish Pavilion for the World's Fair in New York, a building that made Frank Lloyd Wright affirm that Aalto was a genius.[241] His later work leaned towards a more expressive and regional design.[243] In 1952 he married for the second time another colleague, Elissa Mäkiniemi, with whom he designed the municipal center of Seinäjoki, composed of the town hall, a church, a theater, a library and a multidisciplinary room. Since 1960 he worked on the urban reorganization of Helsinki. He carried out works in various countries, such as the Aalborg Art Museum (Denmark) or the Siena Cultural Center (Italy).[241]

Eastern Europe

In the Soviet Union, the end of constructivism and the promotion of socialist realism by Stalinism caused the absence of rationalist proposals in the country since the beginning of the 1930s. This was staged with the competition for the Palace of the Soviets in 1931, which was attended by renowned rationalist architects such as Gropius and Le Corbusier, as well as numerous Russian constructivists, but which was awarded to the academic Boris Iofán. [266] Despite everything, it is worth noting the presence of a building designed by Le Corbusier in Moscow, the Centrosojuz (1928-1936), headquarters of the Central Union of Consumer Cooperatives (currently the State Statistics Committee).[267] However, the end of the Stalinist dictatorship led to the return of rationalism since 1955, thanks to Khrushchev's support for functionalism and industrialization, which led to an architecture that was linked to the International Style in its most productivist aspect, without any type of remembrance of the previous constructivism. From the Modern Movement they adopted centralized planning as a methodology, which they considered appropriate for a socialist system, and which they applied to the growth process of urban structures, with a special interest in collective housing, based on serialization and prefabrication. Public buildings were also designed with a great display of modern materials and technologies.[268] The so-called "Soviet modernism" combined rationalism and a certain monumental character inherited from socialist realism, with a certain influence of English brutalism and the Japanese metabolism. Among the main achievements are: the National Library in Ashgabat, Turkmenistan (1969-1975, by Abdullah Akhmedov"), Boris Shpak") and Vladimir Alekseev"); the Orlov Museum of Paleontology in Moscow (1972-1987), by Yuri Platonov"); the former Ministry of Transport in Tbilisi, Georgia (1977-1979, now Bank of Georgia), by Georgi Chakhava") and Zurab Dzhalaganiya"); the Lenin Museum in Gorky (1975-1987), by Leonid Pavlov; and the Druzhba Sanatorium in Yalta, Ukraine (1986), by Igor Vasilevsky").[269]​.

In Czechoslovakia, born after the First World War, it was influenced by its proximity to German rationalism, of which it also had a direct contribution in its territory: the Tugendhat villa of Ludwig Mies van der Rohe, in Brno. Jiří Kroha Fine Arts Pavilion. It is also worth mentioning the Devětsil group, founded in 1920 by Karel Teige, Jaromír Krejcar and Josef Chochol, who published several magazines on modern architecture, which were however criticized for their excessive concern with form.[270] Two Werkbundsiedlungen were held in Czechoslovakia: in Brno in 1928 (known as Nový Dům, "New House"), in which nine members of the Czechoslovak Werkbund built sixteen single-family houses in the Brno-Žabovřesky district;[271]​ and in Prague in 1932-1933 (Baba neighborhood), which with the general planning of Pavel Janák, various houses designed by eighteen architects, all Czech except the Dutch Mart Stam, were also built.[272]​.

Italy

After the utopian futurist formulations, in the 1920s Italian architecture moved towards rationalism, through several groups that sought to integrate Italian architecture into the international avant-garde: Gruppo 7 and M.I.A.R. The first was founded in 1926 in Milan by seven architects from the Milan Polytechnic: Giuseppe Terragni, Luigi Figini, Guido Frette"), Sebastiano Larco"), Gino Pollini, Carlo Enrico Rava") and Ubaldo Castagnoli") (replaced a few months later by Adalberto Libera). 1927, they opposed both the "vain and destructive fury" of Futurism and the "artificial impetus" of the Novecento "Novecento (art)"), a movement founded in 1922 that sought to renew art without breaking with tradition - hence its name, which was linked to the Quattrocento and the Cinquecento -, with the idea of reinterpreting classical architecture in a modern way but without losing its essence. Faced with this, Gruppo 7 sought to adapt the International Style to the Italian idiosyncrasy, under the premise that "true architecture must evolve from a strict adherence to logic and reason."[297]​.

The group became known at the 1927 Monza Biennale, where they exhibited several industrial-inspired models and designs, which shortly after were shown at the Deutscher Werkbund exhibition in Stuttgart. The first rationalist building was built by Terragni, the main exponent of the group, an apartment block called Novocomum - better known as "the Transatlantic" - located in Como (1927-1928), which denotes the Lecorbusierian influence, as well as constructivism and metaphysical painting, achieving a synthesis of national and international sources. In 1928, a large exhibition was organized in Rome entitled Esposizione dell'Architettura Razionale, in which both Gruppo 7 and other Italian rationalist architects participated and which led to the convergence of all of them into a larger group, giving rise to the M.I.A.R.[298]​.

The M.I.A.R. (Movimento Italiano per l'Architettura Razionale) was founded in 1930. Along with some of the members of Gruppo 7 such as Terragni, Figini, Libera and Pollini, they were joined by architects from all over Italy such as Luciano Baldessari, Giuseppe Pagano") and Mario Ridolfi"). Its premises were based on those of the Milanese group, the adaptation of international currents to Italian architecture, again with the competition of the Novecento, which was favored by the fascist dictatorship of Benito Mussolini, who considered avant-garde artists as "degenerates." To make themselves known, in 1931 they organized the II Esposizione dell'Architettura Razionale in Rome, for which the art critic Pietro Maria Bardi wrote the Manifesto of Rational Architecture and a Report for Mussolini on architecture.[298]​.

The group's main achievement was the Casa del Fascio in Como (1932-1936, current Casa del Popolo), the work of Giuseppe Terragni. Conceived as the headquarters of local fascists, it was made up of a white cube, located around a patio with a glass roof and covered in marble. Other works by Terragni were: the Rustici house (1936-1937), the EUR Congress Building (1938, with Pietro Lingeri") and Cesare Cattaneo), the Casa del Fascio in Lissone (1938-1939, with Antonio Carminati")) and the Giuliani Frigerio house in Como (1939-1940).[299] It is also worth highlighting the residential and industrial projects for the company. Olivetti in Ivrea "Ivrea (Italy)") carried out by Figini and Pollini. Other works by the group were: the Casa Elettrica (1930), by Figini, Pollini and Pietro Bottoni"); and the press pavilion by Luciano Baldessari and the graphic arts center by Giovanni Muzio for the I Milan Triennale in 1933.[300]​ In the late 1930s The group was increasingly persecuted by fascism and by the association, defenders like German Nazism of an anti-modern style, so the group's activities practically ceased, definitively disappearing after Terragni's death in 1941.[301]​

Spain

In Spain, rationalism arrived late, at the end of the 1920s, so its reception came in an established, uncritical way, and its first exponents adopted it in an epidermal, eclectic way, transferring its solutions without considering a possible adaptation to the national environment. One of these first pioneers was Luis Gutiérrez Soto, author of works of notable quality but out of context, such as the Europa (1928) and Barceló (1931) cinemas in Madrid, the Madrid-Barajas airport (1930) and the Bar Chicote in Madrid (1931).[309]​.

In 1928, Le Corbusier gave lectures at the Institución Libre de Enseñanza in Madrid that had a powerful influence on the young architects of that time. Some of them joined together under the acronym GATEPAC (Group of Spanish Architects and Technicians for the Progress of Contemporary Architecture). This group was founded in Zaragoza on October 26, 1930 with three subgroups: Center, located in Madrid, formed by Fernando García Mercadal, Víctor Calvo, Santiago Esteban de la Mora, Manuel Aníbal Álvarez"), Manuel Martínez Chumillas") and Felipe López Delgado; North, located in the Basque Country, which had José Manuel Aizpurúa, Joaquín Labayen and Luis Vallejo; and Este or GATCPAC (Group of Catalan Architects and Technicians for the Progress of Contemporary Architecture) in Catalonia, the most active group, among whose members stood out Josep Lluís Sert, Josep Torres Clavé, Joan Baptista Subirana, Sixte Illescas, Germán Rodríguez Arias, Ricardo de Churruca, Antoni and Ramon Puig i Gairalt, Raimon Duran i Reynals, Jaume Mestres i Fossas and Antoni Bonet Castellana.[50]​ The group's purpose was to "contribute in our country to the development of the new universal orientation in architecture and to solve and study the problems that arise in its adaptation to our environment."[310]​.

The group was a member of the CIAM and, in March 1932, organized a CIRPAC meeting in Barcelona in order to prepare the Moscow CIAM - finally held in Athens in 1933 -, in which Le Corbusier, Victor Bourgeois, Walter Gropius, Sigfried Giedion and Cornelis van Eesteren gave lectures.[311] As a disseminating organ of their activities they published a magazine, A. C. Documents of Contemporary Activity (1931-1937), based on avant-garde magazines such as Das Neue Frankfurt, directed by Ernst May, or L'Esprit Nouveau, by Le Corbusier and Amédée Ozenfant.[312]​ In 1933 the northern and central groups dissolved, leaving only the GATCPAC as an active group until the end of the War Civil.[313]​.

The Central sector had little activity as a group—only the organization of some congresses and a certain participation in the magazine A.C., published in Barcelona—, and showed a certain internal incoherence.[314] Fernando García Mercadal, one of the founders of the CIAM in 1928 and Spanish delegate of CIRPAC, stood out.[315] A member of the so-called generation of '25, his style moved like that of his co-religionists in a rationalism. marked by a certain academic heritage and interpreted modern language in a more formalist than programmatic way. His first project close to rationalism was the pavilion in Zaragoza (1927), which denotes a certain influence of . Later, it is worth mentioning the Museum of Modern Art "Museo de Arte Moderno (Spain)") in Madrid (1933), from which he moved away from the avant-garde.[316]​.

Portugal

The first vestiges of rationalist architecture emerged in the mid-1920s with a certain influence of Le Corbusier, Gropius and Robert Mallet-Stevens, as denoted in works such as the Capitol cinema-theater by Luís Cristino da Silva (1925-1931), the Instituto Superior Técnico by Porfírio Pardal Monteiro (1927-1932) and the Radiology Pavilion by Carlos João Chambers Ramos (1927-1933), all in Lisbon.[343] In addition to the above, it is worth mentioning Cassiano Branco, author of the Hotel Victoria in Lisbon (1934-1936); and Francisco Keil do Amaral, strongly influenced by the Dutchman Dudok (Secil School in Setúbal, 1938-1940; Lisbon airport, 1938-1942).[344]​.

During the beginning of the Salazar dictatorship, a reversal occurred, in which, as in other totalitarian regimes of the time, architecture returned to classicist academicism, with a special reference in the pombaline baroque "Architecture of Portugal") (soft Portuguese style).[345] This began to soften starting in the 1950s, when a new generation of architects took up the modern language. It is worth mentioning Rui Jervis Atouguia, author of the project for the Estacas neighborhood in Lisbon, inspired by the Letter of Athens (1949), the school in the São Miguel neighborhood, where he applies the Lecorbusierian brise-soleil (1949-1955) and the Calouste Gulbenkian Foundation (1959-1969), with Pedro Cid") and Alberto Pessoa;[346]​ Of Pessoa himself, it is worth highlighting the Infante Santo housing complex in Lisbon (1952-1955), blocks suspended on pilotis;[246]​ Jorge Segurado, influenced by Dutch architecture, author of the Mint in Lisbon (1953);[347]​ Fernando Távora, author of the Campo Alegre urban plans (1949) and the Ramalde neighborhood in Porto (1952-1962), inspired by the Letter from Athens, as well as works where he develops a regionalized rationalism in the style of Aalto or Le Corbusier in India (Escuela Primaria do Cedro in Vila Nova de Gaia, 1957-1961; Ofir's house, 1957-1958);[348] Nuno Teotónio Pereira, author with Bartolomeu Costa Cabral") from the Aguas Libres housing complex in Lisbon (1953), one of the largest in the International Style in Portugal; the Lisbon Industries (1957).[344]​.

Greece

Rationalism was introduced little by little in Greece in the 1930s, coexisting with traditional architecture. Among the first works, a villa in Glyfada by Stamos Papadakis" (1933) stands out. During the Second World War several architects left the country and settled in France, where they entered Le Corbusier's workshop, such as Georges Candilis, Iannis Xenakis and Aristomenes Provelengios"). After the war, the country began a vast reconstruction process, although the real estate sector was abandoned to private investment. In the 1950s, several large projects were developed: in 1955 Dimitris Pikionis was commissioned to organize the area surrounding the Acropolis; The following year, Konstantinos Dekavallas") was commissioned to rebuild the island of Santorini, devastated by an earthquake, for which he developed an ambitious project of Lecorbusierian influence; during those years Aris Konstantinidis also developed one of the few state-financed social housing programs, while, as director of the Studies Office of the National Tourism Agency, he was in charge of building numerous hotels, such as those in Kalambaka, Epidaurus and the island of Poros "Poros (Greece)"). In the 1960s, it is worth highlighting the construction of several university complexes in Athens, Thessaloniki, Crete and other places.[351]​.

Leading architects include Dimitris Pikionis, Nikolaos Mitsakis and Patroklos Karantinos. The former trained as an engineer in Athens and completed his studies at the École des Beaux-Arts in Paris. His early works denote the rationalist influence due to their functionality, simplicity and use of the open plan, such as some single-family houses, a school in Aegina, an open-air theater in Athens and a school in Lycabettus. Since 1935 he combined rationalism and popular architecture: Experimental School in Thessaloniki (1935), residential complex of Aixoni, villa and kindergarten of Filotei (1950-1960), mayor's office of Volos (1961). Between 1955 and 1958 he was in charge of the planning of the surroundings of the Acropolis and the Philopagos Hill.[352] Mitsakis studied in Athens and was a strong defender of modern architecture. He worked in the Ministry of Education, where he was in charge of the construction of numerous schools, with a clear Lecorbusierian influence, in which he combined modern technology and traditional materials; The Aristotle girls' school in Athens, the school complex in the Hagia Sophia neighborhood in Thessaloniki, the Dimitsana Lyceum and the schools of Naxos "Naxos (island)") and Tinos stand out. He died in the Second World War.[353] Karantinos graduated from the Athens School of Architecture and completed his training in Paris with Auguste Perret. He was a member of the CIAM, for which he was in charge of organizing the IV Congress in Athens (1933). He participated as coordinator in the school buildings program initiated in 1928 by Eleftherios Venizelos. His works include several buildings for the University of Thessaloniki (1948-1960) and the archaeological museums of Iraklion and Thessaloniki (1960).[283]

United States and Canada

The first exponents of rationalist architecture in the United States came in the 1920s at the hands of immigrant architects, such as the Austrians Rudolf Schindler and Richard Neutra, established in California. Both were influenced by Adolf Loos, Erich Mendelsohn and Frank Lloyd Wright. His first major project was the Schindler-Chase house in West Hollywood (1921-1922), with concrete floors, prefabricated walls, and wooden ceilings and internal partitions. His most famous work is the Lovell Beach House in Newport Beach (1925-1926), with a cantilevered structure of five concrete pillars that elevate the house above the beach and a two-level space that "highlights the unity and continuity of the overall volume of the building's interior," according to Hitchcock and Johnson. Schindler's other works were: the Wolfe House in Avalon "Avalon (California)"), Catalina Island "Santa Catalina Island (California)") (1928-1929), the Rodakiewicz House in Los Angeles (1937), the Hiler House in Hollywood (1944) and the Bethlehem Baptist Church in Los Angeles (1944).[355] Neutra's work differs from rationalism. European in his search for greater luxury and comfort - not in vain were they residences for Hollywood stars - as well as a greater integration of the house into the landscape, with large windows that sought transparency and provided great luminosity.[356] Settled in the United States in 1923, he also worked with Wright in Taliesin (Wisconsin). His best work is the Lovell Health House in Griffith Park, Los Angeles (1927-1929), built for the same client as Schindler's Newport Beach house, Dr. Philip Lovell; This is a nursing home, a full example of internationalism due to its horizontality and its glass and metal structure. Other works by Neutra were the Josef von Sternberg house in Northridge "Northridge (Los Angeles)"), Los Angeles (1936), the Kaufmann house in Palm Springs (1947) and the Tremaine House in Santa Barbara "Santa Barbara (California)") (1947-1948).[357]

When Franklin Roosevelt became president of the country in 1932, he began a broad construction program—within the economic policy of the New Deal—to alleviate the effects of the crash of 1929, which largely included the principles of low-cost housing that had been developed in Europe. Walter Gropius and Marcel Breuer designed a working-class town in New Kensington (Pennsylvania) in 1940, based on prefabricated housing. Gropius collaborated with the General Panel Corporation for the standardization of structural parts, which became a common construction method.[356] The New Deal policy favored the dissemination of a new type of architecture that was more functional and linked to industrial design, in which the influence of designers such as Norman Bel Geddes and Henry Dreyfuss was noted. In this context, American architecture began to distance itself slightly from the rigid European cubic rationalism, with more functional and aerodynamic forms (Streamline moderne), as denoted in the Coca-Cola bottling factory in Los Angeles (1936), by Robert V. Derrah").[358]

Brazil

One of the main Latin American countries where rationalist architecture had an outstanding development was Brazil. The first exponents came in the 1920s at the hands of the Russian émigré Gregori Warchavchik, author of the first rationalist houses in São Paulo, such as his own (1927-1928) and the Casa Moderna (1930).[233] He worked associated with Lúcio Costa, who would be one of the main architects of the International Style in Brazil. The main impulse to the new style came thanks to the 1930 revolution led by Getúlio Vargas, of a progressive type. Culture). Costa had the advice of Le Corbusier, who spent three weeks in the country in 1936 and left his mark on some features of the new building, such as the use of brise-soleil. It is a fourteen-story skyscraper raised on pilotis, with a façade in the form of a grid of vertical screens with adjustable horizontal panels.[394]​.

The style took hold during the 1930s and 1940s, but got a definitive boost with the decision in 1956 by President Juscelino Kubitschek to move the capital to a new city built from scratch: Brasilia (1956-1960). The new city was entrusted to Lúcio Costa in the urban planning field (for its planning see here), while Oscar Niemeyer was in charge of construction.[395]​ Niemeyer adopted the Lecorbusierian language, adapting it to the baroque tradition of the country, which is denoted in his use of curved surfaces.[396]​ The nerve center of the new capital is located in the Plaza de los Tres Poderes, named after the three public powers that are found around the square: the executive, represented by the Palácio do Planalto (presidential headquarters); the legislative, represented by the Nereu Ramos Palace (headquarters of the National Congress); and the judicial, represented by the Supreme Federal Court (1958-1960). Both the Palácio do Planalto and the Supreme Court have a similar design, formed by a glass box with a structural frame of modern but somewhat classicist design. The National Congress presents a greater innovation: it is formed by a low rectangular building that serves as a podium for an elevated plaza accessed by a pedestrian ramp, above which rise two twin blocks in the center and two sculptural forms that crown the chambers of the Assembly (Senate and Deputies), one in the shape of a dome and the other in the shape of a bowl. The shape of the central buildings is reminiscent of the United Nations headquarters, in whose design Niemeyer intervened. His most visually poetic work was the Cathedral of Our Lady Aparecida (1959-1970), with a hyperbolic concrete structure in the shape of a crown of thorns, whose nerves are intertwined with a metal mesh of endothermic polygonal glass, in a combination of white and blue that evoke the sky and the sea; Most of the interior building is underground, while on the surface there is the bell tower, free from the church, in addition to the sculptures of the apostles by Alfredo Ceschiatti. In addition to these buildings, he built the Palácio da Alvorada (1956-1958), the president's residence, a rectangular box with a glass façade and an expressionist colonnade, with a barred interior; the Cláudio Santoro National Theater (1958-1981), shaped like an irregular pyramid; and the Itamaraty Palace, headquarters of the Ministry of Foreign Affairs (1962-1970), made with raw concrete and a design that combines classic and modern forms.[397]​.

Latin America

In Latin America, the hegemonic style until the Second World War was neocolonial, although since the 1930s there were various exponents of rationalist architecture. However, since 1945 there was a new architectural effervescence that had the International Style as a reference, although contextualized to the socioeconomic reality of Latin American countries, with a more monumental and exuberant, structuralist seal and with a desire to integrate all the arts.[402] According to Josep Maria Montaner, «in Latin America there are the most interesting, spontaneous and daring experiences of searching for their own interpretation of the language. rationalist».[403]​.

Among the various Latin American countries, two trends can be observed: one that is more international and prone to the use of advanced technologies, as in Argentina, Chile, Cuba and Venezuela; another of a more national character and more artisanal procedures, with allusions to pre-Columbian architecture - especially in the pictorial, sculptural or ceramic decoration -, as in Mexico, Colombia and Peru.[404] Likewise, two periods should be distinguished: the years 1940 and 1950, marked by a rapid diffusion of rationalism, especially in Mexico and Argentina; and the years 1960 and 1970, in which the movement spread to other Latin American countries, while the crisis of the modern Movement began at the end of this period.[404]​.

It should be noted that Le Corbusier had numerous disciples in Latin America: Jorge Ferrari Hardoy, Juan Kurchan and Conrado Sondereguer") in Argentina; Emilio Duhart, Roberto Matta, Guillermo Jullian and Roberto Dávila Carson") in Chile; Rogelio Salmona and Germán Samper in Colombia; Enrique de la Mora, Teodoro González de León, Enrique Castañeda") and Vicente Medel") in Mexico; Roberto Waceham") in Peru; Carlos Gómez Gavazzo and Justino Sierralta") in Uruguay; and Augusto Tobito Acevedo") in Venezuela.[405]​ In addition to the Lecorbusierian influence, Latin American architecture also shows the influence of other rationalist masters such as Gropius, Mies van der Rohe and Alvar Aalto, as well as the organicist Frank Lloyd Wright.[403]​.

In Argentina, as there was no pre-existing indigenous architecture, the construction models were always of European origin. The first rationalist vestiges date from the late 1930s: in 1938 the Spanish emigrant Antoni Bonet Castellana—former member of GATCPAC—founded, together with Jorge Ferrari Hardoy, Juan Kurchan and other young architects[note 7]​ the Austral Group (1938-1945), with clear Lecorbusierian influence—the three met in Le Corbusier's studio in Paris—which promoted rationalism. with a certain surrealist ascendancy, interest in psychology, concern for the landscape and incorporation of local techniques and materials. Some of his works were: the house located between Paraguay and Suipacha streets in Buenos Aires (1938-1939), the OKS house in Martínez "Martínez (Buenos Aires)") (1954-1958), the Rivadavia tower in Mar del Plata (1956) and the Cristal Plano Pavilion at the Sesquicentennial Fair in Buenos Aires (1960), by Bonet; and the building on Virrey del Pino Street in Buenos Aires (1941-1943), by Ferrari and Kurchan. Another architect of Lecorbusierian influence was Amancio Williams, author of his parents' summer house - known as Casa sobre el Arroyo - in Mar del Plata (1943-1945), a work of great originality in that he built the house on a large vault.[407]​.

Asia

On the Asian continent, rationalism had a notable development in India, especially thanks to the presence of Le Corbusier, who built several buildings in Ahmedabad and Chandigarh between 1951 and 1965. Chandigarh was a newly built city after the division of the Punjab between India and Pakistan, since its previous capital, Lahore, fell into Pakistani territory. The urban planning project was entrusted to Le Corbusier, who had the collaboration of Pierre Jeanneret, Maxwell Fry and Jane Drew (for its layout see here).[435]​ In his buildings, he applied the postulates of his Unité d'Habitation and preferably used raw concrete, a material suitable for the material circumstances of the country.[436]​ Among the government buildings, the Capitol Complex (1951-1962) stood out, composed of three buildings: the Legislative Assembly, the Secretariat Building and the Palace of Justice, as well as a plaza-monument baptized Open Hand ("open hand").[437] For its layout, the Modulor system was used, as well as a construction language based on the repetition of modules at different scales, such as terraces, brise-soleil and the traditional Indian chhatri, a type of parasol. In the Assembly (1951-1962) he designed a rectangular box with a façade with a repetitive pattern and a side entrance composed of a porch of spoiler-shaped pillars that supports a curved roof. The High Court of Justice (1951-1955) is a rectangular box with a cantilevered vaulted shell and a façade composed of a pattern of recessed brise-soleil, while the entrance features three large columns rising to the roof. The Secretariat (1951-1958) is a long and narrow block also composed of repetitive modules with brise-soleil and roof-terrace. Another of the Lecorbusierian buildings in the new city was the Government Museum and Art Gallery.[438]​.

In Ahmedabad, Le Corbusier built two houses: Sarabhai and Shodan, both from 1951-1956. The first features a design of eight juxtaposed barrel vaults, with thick walls and a grass-covered roof to combat the heat. The second consists of a reinforced concrete box with cured slits and a cantilevered roof to act as a parasol, under which a terrace is located, following the precepts of the Maison-Domino. On a larger scale, in the same city he created the building of the Mill homeowners' association (1951-1954), in which he adapted his "five points" to the Indian context, with a promenade architecturale with an open floor plan and Domino structure, a free façade with brise-soleil and a cantilevered pavilion with a terrace-garden; and the Ahmedabad Cultural Center (1951-1958), a complex composed of brick compartments with open spaces and a series of internal courtyards with walls covered with vines.[439]​.

The presence of Le Corbusier promoted rationalist architecture in the country, which had government support, since after the independence of India in 1947 the new authorities were looking for a national style in line with modernity that would show the image of the emerging nation.[440] Indian rationalist architecture followed in the wake of Le Corbusier's final stage, with a more "heroic" tone and marked by the use of raw concrete. The most outstanding disciple of the Swiss architect was Balkrishna Doshi, who worked in his Paris studio between 1950 and 1954. Returning to his country, he was the author of the homes for the Ahmedabad Textile Industries Research Association (1957-1960) and the Ahmedabad School of Architecture (1968). Charles Mark Correa studied at the Massachusetts Institute of Technology and opened his office in Bombay in 1958. He was the author of the administrative building of Anand University (1958-1960), the Ramkrishna House in Ahmedabad (1962-1964) and the Salvation Church in Bombay (1974-1977). Achyut Kanvinde was a student of Gropius at Harvard and, upon returning to his country, he was the author of various Bauhausian-style buildings, among which the Indian Institute of Technology in Kanpur (1959-1966) stands out. Shiv Nath Prasad") remained faithful to Lecorbusierian orthodoxy until the 1970s, as can be seen in his Akbar Hotel in New Delhi (1965-1969). It is also worth highlighting the presence in India of Louis Kahn, author of the Indian Institute of Management in Ahmedabad (1962-1974), a series of brick blocks that combined cubic and cylindrical shapes. Based in India since 1952, the American Joseph Allen Stein was the author of several projects in New Delhi, such as the India International Center (1958-1962) and the Ford Foundation building (1966-1968, with Garrett Eckbo).[441]​.

Africa

The African continent was divided for the most part since the century into colonies administered by European powers, until after the Second World War they gradually became independent from their metropolises. In the French colonies of the Maghreb, in North Africa, the majority of projects were by French architects. Le Corbusier himself developed an urban plan for the city of Algiers in 1932 - called the Obús Plan - which was ultimately not executed due to its utopian approach and local difficulties in its practical implementation. (1938-1942), not executed.[472] Another work by Le Corbusier in the Maghreb was the Baizeau villa in Carthage, Tunisia (1928), adapted to the climatic conditions of the area: it has an anti-sun screen that provides shade and the rooms are interconnected to promote ventilation.[473] A disciple of his, the also Swiss Pierre-André Émery, worked in Algiers from 1925 to 1962, where he led the new generation of modern architects; His works include the working-class mine towns of Ouenza (1948-1953), the schools of Ben-Akhoun (1953) and Châteauneuf (1954), several buildings for Électricité et Gaz d'Algérie and the Protestant temple of Hussein-Dey (1960).[474] Oscar Niemeyer, author of the University of Constantine, also worked in this country. (1968-1970) and the Ministry of Foreign Affairs in Algiers (1974).[211]​.

In Morocco, rationalism had its first vestiges in the 1930s with some architects of Lecorbusierian influence such as Marcel Desmet") and Maurice Sori"), authors of several buildings in Casablanca. In the second post-war period, a generation of young architects (Georges Candilis, Gaston Jaubert, Élie Azagury, Jean-François Zévaco, Jean Chemineau) led the transformation of cities such as Rabat and Casablanca, and formed GAMMA, the local branch of CIAM. and Nids d'abeille) by Georges Candilis, Shadrach Woods and Vladimir Bodiansky (1951-1956), based on the Lecorbusierian Unité of vertical blocks with brise-soleil balconies and garden terraces, combined with lower buildings. André Lurçat also built a housing estate in Casablanca (1953-1955), inspired by his Hotel Nord-Sud in Corsica.[476]​.

In West Africa, modern architecture developed especially in Nigeria, especially thanks to the presence of Jane Drew and Maxwell Fry, installed in this country as advisors for territorial planning in the English colonial Office. His main work was the University of Ibadan (1953-1959). It is also worth highlighting the presence of Walter Gropius, author of the University of Lagos (1963), as well as Ove Arup, author of several industrial buildings, and the English firms Godwin, Hopwood & Kuye, Watkins Gray International and James Cubitt & Partners, responsible for several buildings in Lagos.[477]​ The Israeli Arieh Sharon was responsible for the University of Ife (1960-1970).[478]​.

In South Africa, the Lecorbusierian influence was also received, as denoted in the work of Rex Martienssen"), author of the Peterhouse apartments in Johannesburg (1934-1935), inspired by the Savoye villa.[476] Another exponent was Norman Hanson"), who also shows the influence of the Swiss architect in his 20th Century Cinema in Johannesburg (1940). Some exiled German architects, most of whom trained at the Bauhaus, also developed their work in this country, such as Steffan Ahrends"), Helmut Stauch") and Bernard Pabst"). In the second post-war period, the influence came from the United States, especially in the construction of skyscrapers with metal structures and curtain walls, such as those built in Johannesburg by firms such as Skidmore, Owings & Merrill (Carlton Center Office Tower, 1973) and Hentrich Petschnigg. & Partners (Standard Bank Centre, 1970).[479]​.

Oceania

Australia remained faithful to the architecture of the colonial tradition until the end of the Second World War, when new international trends began to arrive. When this occurred, a variant of rationalism was developed that was innovative and not an imitation of the works of modern masters, especially thanks to Harry Seidler and Sydney Ancher. Austrian by birth, Seidler studied at Harvard's Graduate School of Design and Black Mountain College. He worked with Marcel Breuer in New York and with Oscar Niemeyer in Rio de Janeiro and, in 1948, opened his own studio in Sydney. His early works, such as the Rose Seidler house in Sydney (1948-1950), still show a canonical rationalism, but in the 1960s he evolved towards more minimalist forms, influenced by the painting of Frank Stella, with repetitive forms that combined rectangular and curved shapes, and a high quality of execution, as in the Australia Square Office Tower in Sydney (1961-1967, with Pier Luigi Nervi).[480] Other works of his were: the office of the Commonwealth Trade Group in Canberra (1970-1975), the Australian embassy in Paris (1973-1977) and the Riverside Center in Brisbane (1983-1986).[161] Sydney Ancher adapted the Miesian language to the local Australian environment, as in the Farley house in Warringah (1947), the English house in Saint Ives (1951) and the Ancher House in Neutral Bay (1957).[481] Other exponents of modern architecture were: Samuel Lipson"), Hugh Buhrich"), Frederick Romberg") and Mary Turner Shaw.[482]​.

In New Zealand there are no examples of modern architecture until after the Second World War. The first exponents were immigrants such as Heinrich Kulka") and Ernst Plischke, who however were poorly received by the local architectural community, still mired in the colonial style of previous decades. A first reaction against the prevailing academicism was that of Miles Warren and Peter Beaven"), who developed their work in different ways, the first with a certain brutalist influence (Dorset Street apartments in Christchurch, 1956-1957) and the second with a more florid style, as in his Lyttleton Road Tunnel Building (1963).[483]​.

Urban planning had a great development in the 20th century, since the progressive increase in the urban population since the beginning of the Industrial Revolution led to a growing interest in seeking new formulas and solutions to satisfy the housing and infrastructure needs of society. If in 1800 there were about 200 cities in the world with more than 20,000 inhabitants, with a total of 21.7 million inhabitants (2.4% of the total population), in 1950 there were 5,509 cities of that size, with 502.2 million inhabitants (20.9% of the total).[484] Rationalism, due to its progressive and social ideas, put great effort into developing urban planning theories that were universally applicable, with a special emphasis on hygienic and functional solutions, that satisfied all aspects inherent to the city, both economic and technological, cultural and ecological.[485]​.

The main rationalist urbanist was Le Corbusier, who set out his principles in Urbanisme (1925), where he developed his ideas about a functional city based on order and linearity. Already in 1922 he had outlined his project for a Ville contemporaine pour three milions d'habitants, in which he located an urban center with a series of office skyscrapers around a communications hub surrounded by various residential, service and leisure sectors, with abundant green areas and hierarchically ordered streets.[486]​ The buildings would be of three typologies: cruciform skyscrapers in the center, houses à redent[note 8]​ in the middle and immeubles-villas in the periphery.[488]​ In his 1925 book, Le Corbusier established four essential points about urban planning: decongest the city center, increase its density, increase the means of transportation and increase parks and open spaces. He also noted that "modern urban planning is born with a new architecture."[489] He applied this scheme to his Voisin Plan for Paris (1925) - not carried out -, in which he proposed the demolition of 40 hectares of old buildings on the right bank of the Seine, whose space would occupy a large green esplanade that would house nineteen tall skyscrapers with a cross plan, with straight roads and at different levels.[490]​[491]​ In 1933 he reformulated his theories with the name Ville Radieuse ("radiant city"), an almost utopian project that combined functionality with ecological concern, with giant blocks of apartments separated from each other to guarantee their exposure to the sun, large garden spaces, separation of functions and efficient communication routes. Le Corbusier was the "great creator of the utopia of the modern city in its physical aspect", according to Martin Meyerson.[492] In addition to Paris, Le Corbusier developed urban planning projects for São Paulo and Rio de Janeiro (1929-1930), Algiers (1930), Barcelona (1932-1935), Geneva (1933), Stockholm (1933), Antwerp (1933), Buenos Aires Aires (1938-1940), Saint-Dié (1945), Bogotá (1949-1952), Marseille (1950), Izmir (1950) and Chandigarh (1951-1965), the only one that was executed.[145]​.

The realization of all these ideas occurred in the Letter of Athens, one of the main manifestos of rationalist urbanism. It was written at the IV CIAM held in Athens in 1933, under the initiative mainly of Le Corbusier, although the writing was carried out by the Swiss architects Werner Max Moser and Rudolf Steiger. It was not published until 1942, anonymously, and in 1944 by Josep Lluís Sert with the title Can our Cities Survive?; Finally, in 1957 it was published under the signature of Le Corbusier. Its content focused on urban planning, with a functional city model opposed to traditional concepts, where the city is based on areas enabled for different functions, such as residential, economic and industrial or recreational (sports and recreation), together with green areas between the different spaces, all of them delimited and structured by rationally arranged road axes. For housing, Le Corbusier's bet was on high-rise buildings. According to his proposal, only the historical monuments, surrounded by green areas, would be saved from the old centers of the cities. This approach inspired many of the urban developments of the 1950s and 1960s.[493]​.

The first achievement inspired by the Athens Charter was the General Extension Plan for Amsterdam (Algemeen Uitbreidingsplan or AUP), prepared by Cornelis van Eesteren and approved in 1935. The objective was the expansion of the city towards the periphery and was prepared based on detailed statistical research, with a subdivision into neighborhoods of 10,000 homes separated by green areas and with open blocks oriented from north to south. The concentration of economic activities in the port center led to dense and compact growth, which however was optimally resolved with a pre-established organization to create cohesive neighborhoods and with a subdivision of tasks by units smaller than the neighborhood supervised by an architect. The plan is still in force and regulates the progressive growth of the city.[494]​.

After the Second World War, rationalist urbanism was applied to the reconstruction of cities devastated by war and its methodology became closer to capitalist economic principles, since its postulates of zoned fragmentation, mass production and prefabrication matched perfectly with capitalist industrial models. A paradigmatic model was that of the English new towns, which brought together the precepts of the garden cities advocated by Ebenezer Howard at the beginning of the century with the rationalist postulates.[495] It is especially worth highlighting the Greater London Plan to decentralize the English capital, approved in the New Towns Act of 1946. Between 1945 and 1951, fourteen new towns were created towns,[note 9]​ among which it is worth highlighting Stevenage (1946) and Harlow (1947), which show a certain influence of the Scandinavian neo-empiricism practiced at that time.[497]​ In the rest of Europe, an extensive program of reforms and new urban projects were also developed: in Scandinavia several new cities emerged (Vallingby"), Farsta and Skärholmen") in Sweden, Tapiola in Finland), as well as several regulatory plans in cities such as Copenhagen (Five Fingers Plan, 1947) or Helsinki, which expanded its municipal territory six times.[498]​ In France, Italy and Germany, most devastated by the war, priority was given to construction over urban projects, so the housing stock grew without adequate planning, except for some cases such as the development plans for Le Havre and Amiens drawn up by Auguste Perret in 1947-1954, the various Unité d'Habitation by Le Corbusier (1952-1964), the neighborhoods planned by the studio Candilis, Josic & Woods (Bagnols-sur-Cèze, 1956-1960; Toulouse-le-Mirail, 1961-1966), the Milan regulatory plan of 1953 or the Hansaviertel neighborhood in Berlin planned for the Interbau "International Exhibition of Berlin (1957)") of 1957.[499]​ In the Netherlands there was a greater relationship between architecture and urban planning, as in the case of Rotterdam, whose center was completely destroyed in 1940, for which a reconstruction plan drawn up by Cornelius van Traa") and approved in 1946 was drawn up.[500]​ In the eastern countries, the reconstruction of the cities was carried out under the academic style advocated. by the Stalinist dictatorship and only after Stalin's death did some more rationalist projects emerge, such as the housing blocks shown in models at the Brussels General Exhibition of 1958 "First Category General Exhibition of Brussels (1958)").[501]​.

It is also worth noting the urban planning in Israel, a country that grew considerably since its independence in 1948: if previously the Jewish population was 70,000 inhabitants - concentrated mainly in Haifa and Tel Aviv -, between 1948 and 1961 this figure tripled, making it necessary to build new cities, regulated with a territorial plan inspired by the English new towns directed by Arieh Sharon: between 1948 and In 1957, twenty-eight new cities were planned, including Beersheba and Ashdod; In the 1960s two more were created, Karminel") and Arad "Arad (Israel)").[462]

The main urban developments of the Modern Movement were Brasilia (Brazil), Chandigarh (India) and Islamabad (Pakistan). Brasilia (1956-1960), conceived as the country's new capital, was planned by Lúcio Costa, who was inspired by the Charter of Athens and designed a plan made up of two axes that intersect in the shape of a cross, with wide avenues and large spaces that provoke a great sensation of vastness - but equally of loneliness, as has been commonly criticized. In the central part are the official buildings and recreational areas, and around them are the residential, cultural and commercial areas, as well as green areas, stations, airport and all types of infrastructure.[395] Chandigarh was built as the new capital of Punjab between 1951 and 1965, with a project designed by Le Corbusier, Pierre Jeanneret, Maxwell Fry and Jane Drew. Also based on the Charter of Athens, Le Corbusier put into practice his theory of mixed sectors, in which residential areas are differentiated based on density,[435]​ and for residential buildings he applied the postulates of his Unité d'Habitation.[436]​ Islamabad was created as the new capital of Pakistan, with a design by Konstantinos Apostolos Doxiadis (1960), the creator of the concept of ekistics or science of habitat, which examines human settlements from multiple perspectives in search of techniques to solve their inherent problems. Doxiadis developed a purely rational layout and divided the city into sectors differentiated by their function or construction typology, starting from a central node from which the city would expand following a reticular plan.[442]​.

One of the greatest concerns of rationalist architects—especially in Germany—was that of social housing. The ravages of the First World War favored the rise of socialist ideas, to which numerous architects adhered, concerned with finding solutions for the housing needs of the working class. In France, the HBM (habitat à bon marché, "cheap housing") organizations promoted the construction of housing in the so-called "red belt" of Paris, and Henri Sauvage") devised his stepped residential buildings, such as the one on the rue des Amiraux (1913-1928). In the Netherlands, the Amsterdam School experimented with social housing with a sculptural aesthetic, while in Belgium the garden cities through cooperative movements. In Scandinavia, self-construction was encouraged. But the main boom in social housing occurred in Germany, especially during the Weimar Republic, with the phenomenon of siedlung (plural siedlungen, translatable as settlement or urbanization), residential complexes of houses or housing blocks located on the outskirts of large cities, rationally organized with the premises of large spaces, green areas and optimal sanitary conditions. sunlight and ventilation. Among the main achievements are those by Bruno Taut and Martin Wagner "Martin Wagner (architect)") in Berlin (six groups: Garden City Falkenberg, Siedlung Schillerpark, Großiedlung Britz, Wohnstadt Carl Legien, Weiße Stadt and Großiedlung Siemensstadt), by Otto Haesler") in Celle (Italienischer Garten, Georgsgarten) and by Ernst May in Frankfurt. (Römerstadt, Praunheim, Westhausen, Höhenblick), as well as the Weißenhofsiedlung in Stuttgart, the colony organized by the Deutscher Werkbund in 1927 in which numerous international architects participated. In contrast to the typology of houses with gardens sponsored by the siedlungen, in Austria the concept of Höfe (courtyard) was developed, large apartment blocks for collective housing, such as those in Red Vienna, among which the Karl Marx-Hof in Vienna, the work of Karl Ehn (1927), stands out. After the Second World War, large transitional housing plans arose to alleviate the ravages of war, generally financed by the states, while Le Corbusier proposed his Unité d'Habitation (like that of Marseille, 1947-1952), large housing blocks with all the services to constitute self-sufficient entities.[502]​.

The Modern Movement also placed special interest in design, decoration and interior design. One of the most innovative movements in the field of design was the Bauhaus School which, compared to the excessive ornamentation of art deco, introduced a more rational and functional design concept, more adapted to the real needs of people. This school sought to break the barriers between art and crafts, with some influence at the beginning of Arts & Crafts, while later it opted for industrial production. Its objective was "the collective work of art, the Building, within which there were no barriers separating the structural arts from the decorative arts."[119] Students at the school learned theories of form and design, as well as workshops in stone, wood, metal, ceramics, glass, weaving, painting, theater and photography.[503] Its design was based on simplicity, geometric abstraction and the use of primary colors and new technologies, as was evident in the tubular steel furniture. created by Marcel Breuer, the Barcelona chair by Ludwig Mies van der Rohe and Lilly Reich or the lamps designed by Marianne Brandt. In this school, creators stood out - in addition to those previously mentioned - such as László Moholy-Nagy, Oskar Schlemmer, Johannes Itten, Paul Klee, Josef Albers, Vasili Kandinski, Gerhard Marcks or Wilhelm Wagenfeld. the sans serif. In 1925 the Bauhaus founded its own company to market its designs, the Bauhaus GmbH, which published a catalog with its products.[505]​.

Heir to the Bauhaus was the Hochschule für Gestaltung (Higher School of Projection), later called Neues Bauhaus (New Bauhaus), founded in 1953 by Max Bill in Ulm. His design works were characterized by their geometric appearance and minimalism, which became known as the "Ulm style." In the first phase, the school was oriented towards fine arts and crafts and included teachers from the former Bauhaus such as Josef Albers and Johannes Itten. A second phase was marked by the change of management in 1956 from Max Bill to Tomás Maldonado, who reoriented the school towards industrial production. Architects and designers such as Walter Gropius, Mies van der Rohe, Frei Otto, Charles Eames and Richard Buckminster Fuller taught at the Ulm Bauhaus.[189] Bill himself was a designer of notable creativity: he had been a student at the Bauhaus and in the 1930s he worked as a painter, sculptor, architect and graphic designer, while in the 1940s he began in industrial design, with creations such as his aluminum wall clock for Junghans (1957), his wristwatches and his minimalist stool Ulmer Hocker (1954).[506]​.

In the century, industrial design gained progressive prominence, based on intellectual creation and functional design, with an increase in experimentation with new materials (plastic, fiberglass) and greater attention to market needs.[507]​ The basis of industrial design is found in functionalism "Functionalism (architecture)"), a theory that argues that an object that fulfills its function and is made with economy of materials is intrinsically beautiful. This would exclude aesthetics in the design of objects, although such an extreme is rarely put into practice in its entirety. One of the precedents of this theory was the architect Louis Sullivan, who stated that "form follows function", as well as Otto Wagner, who stipulated that "nothing that is not practical can be beautiful."[508] In Germany, architects and designers such as Peter Behrens, Richard Riemerschmid and Bruno Paul, and workshops and associations such as Deutsche Werkstätten, Deutscher Werkbund and the Bauhaus, laid the foundations of industrial design in an early phase. In France, the pioneer was the architect Le Corbusier, who proclaimed the "absolute expressive autonomy of industrially produced objects" and pointed out as basic aspects of the new design the purity of lines, the functionality of the materials and the luminosity of the surfaces.[509]​ After the closure of the Bauhaus by the Nazis in 1933, most of its components were moved to the United Kingdom or the United States, countries that picked up the baton of industrial design.[510]​ In the In the United Kingdom, design had its precedent in the Arts & Crafts workshops. In 1915, the Design and Industries Association was founded with the aim of promoting design and, in 1930, the Society of Industrial Artists was created to bring together professionals in the sector.[511] In the United States, the pioneer was the architect Frank Lloyd Wright, until the emergence of design in the 1930s with figures such as Henry Dreyfuss, Raymond Loewy and Walter Dorwin Teague. In that decade, some Bauhaus masters such as Ludwig Mies van der Rohe, Walter Gropius and László Moholy-Nagy also established themselves, who taught a new generation of designers. Later Charles Eames, George Nelson and Harry Bertoia stood out. In 1944 the Society of Industrial Designers was founded, in 1948 the National Association of Schools of Design and, in 1957, the Industrial Design Educational Association.[511]​.

Later, in Europe, industrial design had two main currents: the Scandinavian and the Italian. The first, represented by Arne Jacobsen, Alvar Aalto, Eero Saarinen and Poul Kjærholm, had its roots in popular art and was based on the naturalness and simplicity of the forms as a fundamental premise of the design, as well as the use of natural materials, although without disdaining steel, which they used frequently. The main fields covered by Scandinavian design were furniture, ceramics, metalwork and glass. For its part, Italian design was more daring and extravagant, with a predilection for bright colors, use of artificial materials such as resin, plastic and conglomerate, as well as steel and more "noble" materials such as marble, and with a creative freedom that ranged from the austerity of Ettore Sottsass, through the rationalism of Joe Colombo, to the refinement of Gae Aulenti. In Spain, a school of designers of notable quality also began in the 1930s, marked by a certain expressiveness, a generally small size of objects and a certain test character, with high-quality prototypes that did not always find an industrial outlet. The starting point is at the GATCPAC, a pioneer in the introduction of modern design in Spain - in 1931 they opened their commercial premises, called MIDVA (Furniture and Decoration of Current Housing) -, with figures such as Josep Lluís Sert, Josep Torres Clavé and Antoni Bonet Castellana; Later it is worth mentioning Antoni de Moragas, Oriol Bohigas, Carlos de Miguel"), José Antonio Coderch, Miguel Milá and Antonio Fernández Alba. In 1955 the Spanish Society of Industrial Design was founded and, in 1960, the Industrial Design Group (ADI-FAD).[512]​.

In the field of interior design, the maximum premise after the First World War was innovation, always subordinated to functionality, leaving out aspects such as comfort or convenience, which were not considered essential. Interior design stopped looking to the past, stopped paying attention to regional styles or forms; They were looking for something new and valid for any geographical area. In the 1920s, the dominant concepts were technology and hygiene: domestic objects were designed according to the latest technological advances and interior design was based on open, sunny and ventilated spaces. As most interior designs were carried out by architects, they were generally subordinated to the external form of the building, which determined the interior planning and type of furniture. On the other hand, rationalism's commitment to the open floor plan led to interiors without rooms, with spaces delimited by screens or by the furniture itself, thereby neglecting aspects such as privacy, noise or smells.[513]​.

The main piece of furniture that was the object of special interest in its design was the chair: according to Christopher Wilk, "no era has produced so many chair designs by architects. Virtually every architect and designer worth mentioning felt obliged to direct their attention to the design of at least one chair. Faced with the excessive coldness and asepsis of these designs, in the 1930s—especially in the United Kingdom—a “comfortable modernism” was promoted, such as that developed by the English firm Isokon, based on greater comfort and aesthetic appearance, for which they turned to wood as a material; Breuer himself made a lounge-chair for Isokon in 1936. On the other hand, the exhibition British Industrial Art in Relation to the Home of 1933 showed the Minimum Flat ("minimum apartment") by Wells Coates, with a kitchen and a bathroom of strict functional design. its simplicity, low cost and mass production; These furniture influenced Le Corbusier and Mies van der Rohe, who used them in the L'Esprit Nouveau pavilion of 1925 and the Weißenhofsiedlung of 1927, respectively. Wood also played a leading role in Scandinavian interior design, a "natural modernism" advocated above all by Alvar Aalto. Apart from furniture, modern interior design gave little consideration to the use of fabrics or other ornaments, and even for the color of the walls, exclusively white was recommended.[516] It is worth highlighting the kitchen design prepared by the Austrian architect Margarete Schütte-Lihotzky, who in 1925 collaborated with Ernst May on his collective housing project for Frankfurt, for which she created the so-called Frankfurt kitchen, provided with built-in furniture and elements. prefabricated, unadorned and well-lit spaces, with a practical, cheap and standardized design.[517]​.

After the Second World War, interior design opted for a more aesthetic appearance, with bright and cheerful colors that made one forget the horrors of war. Postwar shortages of materials and labor generally led to smaller houses and apartments, with well-placed and easy-to-use furniture and appliances. Demand grew for furniture, largely destroyed during the war, with simple design and mass production, such as that advocated by the Utility plan in the United Kingdom. Gordon Russell") designed a line of affordable and comfortable modern designer furniture, inspired by Arts & Crafts. In the United States, the Knoll company also opened a line of mass-produced contemporary furniture. In Germany, the Thonet company launched a series of electronically molded plywood furniture, which was cheap, flexible and resistant. On the other hand, in 1946 the first molded plastic chair was created. In the 1950s the furniture became lighter and smaller, like the one designed at the American Cranbrook Art Academy by Eliel Saarinen or Charles Eames, more organic and comfortable. Isamu Noguchi designed the first table with a glass cover, as well as the first lantern-shaped paper lampshade, then began the leadership in design promoted in Sweden, more minimalist and equally comfortable, flexible, hygienic and affordable, as in the work of Alvar Aalto and Arne Jacobsen. It was here that the flatpack or removable furniture was developed. Ikea. In the United States, open-plan houses emerged, with open spaces, such as those designed by Eero Saarinen and Charles and Ray Eames, with unique spaces subdivided only by changes in the floor covering and by the furniture - especially the storage units of Lecorbusierian design -, while the rooms were placed at mid-height, on a mezzanine. The kitchens became larger and more technological, efficient and utilitarian, although their design was functional. It led to a certain masculinization of these spaces.[518]​.

The main characteristics of modern furniture were: functionality, suppression of all superfluous ornamentation and minimal decoration coming from the same lines of force (shape, material), structure as a total base of the furniture without additions, standardized canons of universal utility and open, clear and simple forms. Prouvé, Eileen Gray, Robert Mallet-Stevens, Pierre Chareau and René Herbst.[520]​.

In general, the interior design of the Modern Movement has been criticized for its lack of comfort and the high cost of its industrial production, since until the 1960s the industry did not achieve standards compatible with the mass production of modern design objects. Thus, the interior decoration of modern architects was limited at the time to an elite of high-income consumers, which contradicted the social principles defended by rationalism.[521]​.

• - Teapot designed at the Bauhaus by Marianne Brandt (1924).

• - Cantilever Chair (1926), by Marcel Breuer.

• - Weißenhof Chair (1927), by Ludwig Mies van der Rohe and Lilly Reich.

• - Paimio Chair (1929-1933), by Alvar Aalto.

• - BKF Chair (1937), by Antoni Bonet Castellana, Juan Kurchan and Jorge Ferrari Hardoy.

• - Utero Chair (1947-1948), by Eero Saarinen.

• - Eames Lounge Chair (1955), by Charles and Ray Eames.

• - Wall clock designed by Max Bill for Junghans (1957).

• - Egg Chair (1958), by Arne Jacobsen.

• - Modern architecture.

• - Functionalism (architecture) "Functionalism (architecture)").

• - Organic architecture.

• - Architects in the Modern Movement.

• - Nordic design

• Accept

• Stockholm Exhibition.

• - Urban vitality.

• - Wikimedia Commons hosts a multimedia category on Rationalism.

• - Wikimedia Commons hosts a multimedia category on International Style.

• - Wikimedia Commons hosts a multimedia category on Modern Movement.