An emergency exit is a special exit structure for "Emergency (disaster)" emergencies, such as a fire: the combined use of regular and special exits allows rapid evacuation, while also providing an alternative if the route to the normal exit is blocked by fire, for example.

They are usually strategically placed with doors opening outward with a crash bar on it and with exit signs leading to it. The name is a reference, however, an emergency exit can also be a main door inside or outside. A fire exit is a special type of emergency exit, mounted on the exterior of a building.

Local building codes often dictate the number of emergency exits needed for a building of a given size. This may include indicating the number of stairs. For a building larger than a private house, modern codes invariably specify at least two sets of stairs. In addition, such stairs must be completely separated from each other. Some architects meet this two-staircase housing requirement in a "double helix" configuration where two staircases occupy the same space, intertwined.[1]​.