Positive balance buildings
Introduction
The Heliotrope is an ecological house designed by German architect Rolf Disch, who also designed the Sonnenschiff (Sun Ship). There are three such houses in Germany, the first experimental version was built in 1994 as an architect's house in Freiburg im Breisgau, while the other two are used as exhibition buildings for the Hansgrohe company in Offenburg and a dentist's laboratory in Hilpoltstein in Bavaria. The Heliotrope in Freiburg was the first building in the world to produce more energy than it uses, all of it completely renewable, emission-free and CO neutral. The structure physically rotates to follow the sun, making the most of natural sunlight and solar heat. Several different power generation modules are used in the building, including a 603-square-foot (56.0 m²) dual-axis photovoltaic solar tracking panel, a geothermal heat exchanger, a combined heat and power (CHP) unit, and solar-thermal balcony railings to provide heat and hot water. These innovations in combination with the residence's superior insulation allow Heliotropo to generate four to six times its energy consumption, depending on the time of year. The Heliotrope is also equipped with a built-in gray water cleaning and natural waste composting system.
At the same time as the Freiburg Heliotrope was built, Hansgrohe contracted Rolf Disch Solar Architecture to design and build another Heliotrope for use as a visitor center and exhibition hall in Offenburg, Germany. A third Heliotrope was then contracted and built in Hilpoltstein, Bavaria, for technical dental laboratory use. Disch's design manages to accommodate the prototype from homes to laboratories, and yet maintains the positive energy balance of the structure. In addition to the original Heliotrope design, Rolf Disch has drawn up plans to build larger versions of the project as a rotating hotel, offering each guest a beautiful view, as well as administrative buildings and even an exhibition pavilion for EXPO 2010 in Shanghai.
Plus Energy
Plus Energy is a concept developed by Rolf Disch that indicates the extreme energy efficiency of a structure to achieve a positive energy balance, actually obtaining more energy than it consumes. With the completion of his private residence, the Heliotrope, in 1994, Disch created the world's first PlusEnergy home. The logic of a home that produces more energy than it consumes is Disch's objective. The next goal in its development was, therefore, the massive application of the concept to residential, commercial and retail space. As the concept developed and gained financial backing, Disch built several more projects with PlusEnergy certifications. PlusEnergy is a simple concept that has been materialized in a technical design. "PlusEnergy is a fundamental environmental imperative," says Disch.[1] Disch believes that passive construction is not enough because passive houses still emit CO2 into the atmosphere.