The residential and office building at Weststrasse 70 in Zurich was built in 1966 and occupies the corner at Birmensdorferstrasse. It has six above-ground stories and three basement levels, is accessed via a circulation core adjoining the courtyard, and has facades with wraparound bands of ribbon windows and spandrels. The internal structure is a skeleton of reinforced concrete. A setback on Weststrasse and a projecting bay on Birmensdorferstrasse give the simple building a distinctive character within the urban space.
The alterations provide for the adaptive reuse of the building. The Karma International gallery has occupied exhibition space at this intersection now for two years. And recently, a Japanese restaurant has opened in the western part of the ground floor. On the floor above is a notary’s office that has been there for years. On the remaining upper floors, we have set up our own offices. The remodeling here primarily entailed the removal of earlier fit-out work.
The top floor is now fitted out with five newly built apartments. In the studios, the position of the main space is dictated by the unit’s location along the outdoor corridor or the facade setback. The two large dwelling units each get a patio – small gardens that we designed with Daniel Ganz – as outdoor space directly on their floor. The living space here explores the archetypal theme of the atrium house with the idea of a floor plan conceived as “landscape” – an interpretation of the plan libre, or free plan.
The mixed-use commercial building at Theaterstrasse 12 is to be given a new facade and an up-to-date use concept that firmly anchors it as a “house on the square.” The simple and neoclassical architecture of the facade features a configuration accentuated in the vertical by colossal pilasters that correspond to the grid of the existing load-bearing structure. The horizontal articulation is provided by two strong cornices that divide the facade into a two-story base and a three-story central section. Above this, the upper story is set back and topped off with a new cylindrical crown. This primary order, with a classical tripartite division, gives the facade a representational character with an identity of its own that relates to the scale of the public square and accentuates the building’s impact from a distance.
Through the choice of materials and a “performance,” the facade on the square is given a contemporary localization. The pilasters are made of textured cast glass that is back laminated with solar cells. Together with photovoltaic panels on the roof, they supply the building with electricity. The pilasters are topped by a series of cylindrical “roof figures” that serve as upright solar collectors to produce hot water. At nightfall, the glass pilasters can be illuminated from behind, exuding a metropolitan aura. Thus the building also changes its character in twilight and at night. Herein lies the performative character of the new facade.
The ground floor entrances and articulation of a piano nobile open up the building to Theaterstrasse and Sechseläutenplatz. The basement remains reserved for retail, while the ground and second floor can be used to flexibly accommodate various retail establishments and food and beverage outlets. The floors above can be built out for use as office space. A small hotel with bar is proposed for the top floor.