In architecture, functionalism is the principle that architects should design a building based on the purpose of that building. This statement is less self-evident than it first appears, and is a matter of confusion and controversy within the profession, particularly in regard to modern architecture. Functionalism had the strongest influence in Germany, Czechoslovakia, the USSR and the Netherlands.
The place of functionalism in building can be traced back to the Vitruvian triad, where 'utilitas' (variously translated as 'commodity', 'convenience', or 'utility') stands alongside 'venustas' (beauty) and 'firmitas' (firmness) as one of three classic goals of architecture. Functionalist views were typical of some gothic revival architects. In particular, Augustus Welby Pugin wrote that "there should be no features about a building which are not necessary for convenience, construction, or propriety" and "all ornament should consist of enrichment of the essential construction of the building".
The debate about functionalism and aesthetics is often framed as a mutually exclusive choice, when in fact there are architects, like Will Bruder, James Polshek and Ken Yeang, who attempt to satisfy all three Vitruvian goals.
In 1896, Chicago architect Louis Sullivan coined the phrase 'form ever follows function' to capture his belief that a building's size, massing, spatial grammar and other characteristics should be driven solely by the function of the building. The implication is that if the functional aspects are satisfied, architectural beauty would naturally and necessarily follow.
Sullivan's credo is often viewed as being ironic in light of his extensive use of intricate ornament, since a common belief among functionalist architects is that ornament serves no function. The credo also does not address whose function he means. The architect of an apartment building, for instance, can easily be at cross-purposes with the owners of the building regarding how the building should look and feel, and they could both be at cross-purposes with the future tenants. Nevertheless, 'form follows function' expresses a significant and enduring idea. Sullivan's protégé Frank Lloyd Wright is also cited as an exemplar of functional design.