The Theater Winterthur, completed in 1979 and designed by architect Frank Krayenbühl, is an extremely idiosyncratic building. Its distinctiveness derives from a mixture of very different architectural principles. The exterior is notable for its stepped massing, which appears monolithic due to its mostly windowless lead sheet cladding. It is reminiscent of the abstract, sometimes mimetic compositions of Alvar Aalto in his later years.

The large roof conceals an open interior, which in turn is defined by sculptural spatial boundaries, such as the “overhanging” concrete volumes of the auditorium, as well as lightweight structures, namely the steel trusses of the roof structure. Both in the auditorium and in the lobbies, the space is characterized by informal qualities, which are recognizable, for example, in the lack of symmetries. This also pertains to the landscape character of the lobbies, which are joined diagonally as a series of terraces. The space is superimposed by the building services, which run exposed to view, as well as differentiated, color-coded elements that show the influence of trends associated with Norman Foster and Renzo Piano that were prevalent at the time.

In view of its architectural qualities and its significance as a historic monument, refurbishing a building like the Theater Winterthur is an eminently architectural task. However, the role of the architect in such cases is not that of an author designing something new. Rather, the architect’s role is that of an advocate who responsibly and meticulously protects the existing qualities.