Function is a key term in architecture. Architects had already appropriated this term in the eighteenth century, and in the twentieth century in particular they quite consciously employed it when pursuing very different, even contradictory, goals. During the past two and a half centuries, the term has been repeatedly reintroduced into the discussion of architecture as an inspiring concept, only to meet with immediate criticism and lose significance. The most recent interval ended around 1980. First, the High Modernism of the 1920s led to the term’s broad popularity, which lasted until the Functionalism of the 1960s and Postmodernism discredited it completely. Until just a few years ago, the observation that something was functional architecture would have been understood almost exclusively in the disparaging sense, as supposedly efficient readying of space and as the antithesis of an interest in form. There are now signs in the discourse on architecture, however, that there is a new interest—reflected in conferences and publications—in the subject of function and its relationship to form.¹ One notices that the antithetical defense of function, on the one hand, or form, on the other, rarely plays a role anymore. Rather, there is an attempt to understand why the themes of the function–form relationship were able to exercise such an attraction for two and a half centuries and a discussion of how they can be invigorated with new meaning today. Function is a term that always came up in architecture when it was necessary to describe something new or a turning point. In view of the challenges architecture faces on practical and theoretical levels, in particular related to globalizing societies and changing natural environments, one might think that the idea of function–form relatedness is again well positioned as part of a paradigm shift for the era to follow star architecture.

What does function mean in architecture? In the past, that question was usually asked when one was actually trying to clarify another question: What does functionalism mean? The latter question arose in architectural discourse in the 1930s. Although the word “functionalism” is found in isolated cases in writings in the 1920s, as the fourth chapter will show, its sudden spread can be dated relatively precisely to the year 1932. The famous 1933 meeting in Athens held by the Congrès Internationaux d’Architecture Moderne (CIAM) was named “The Functional City” during the preceding preparations.² In 1932 Alberto Sartoris published his famous book Gli elementi dell’ architettura funzionale, from which it has been said that “terminological talk of ‘functionalism’ originated.”³ And in the British magazine Architectural Review in 1932, one could sense the tone of contemporary architectural journalism:

If you follow this quotation, the term “functionalism” seems to be due to the search for a powerful name that could cover as best as possible all the currents of the 1920s and had to remain correspondingly vague. Nevertheless, numerous authors in the 1950s and 1960s tried to define the content of the term more precisely. The strategy of doing so by going back to and interpreting the term “function” did not, however, prove very successful at first. The supposedly vague meaning of the word “function” was even used as a main argument why functionalism could not be defined. “The programmatic weakness of functionalism begins already with the nondefinition of the term ‘function,’” wrote Hartmut Seeger in 1968, for example.⁵ And Gerda Müller-Krauspe remarked in 1969 that “the dilemma of functionalism is not least that its early advocates were able to articulate succinct slogans for it whereas they never clarified explicitly what precisely should be understood by function.”⁶ In a broad sweep in 1988–89, Emmanuelle Gallo and Claude Schnaidt formulated eighteen different definitions of functionalism, and they too concluded: “The notion of functionalism lacks consistency. The ambiguity results from the lack of answer to an essential question: What is function?”⁷

Studies of functionalism in architectural theory often begin with a look at etymology. They explain that function comes from the Latin functio, which means performance. Here they immediately run into the problem of what a building or part of a building performs. “With inanimate objects, the term function is misleading, since they do not perform activities,” wrote the architectural theorist Werner Nehls, for example, in his 1966 article “Das Ende der Funktionalistischen Epoche” (The end of the functionalist epoch). He further observed that buildings were understood “as if they were living beings, capable of actions: the knife cuts, the wedge splits,” and concluded from that that “the literal application of the term function merely creates confusion. This also explains the many uncertainties and contradictions that result from its use.”¹³