Allianz Headquarters in Wallisellen
- Frank Kaltenbach
The Richti district borders Zurich’s centre to the north; formerly an industrial site, it now has 1200 residents, offices for 3000, and numerous shops and restaurants. The vicinity to the central station and a variety of public transit lines makes the location all the more attractive. Vittorio Lampugnani’s urban design concept takes the city-block structure of the 19th century as point of departure. Instead of the solid masonry walls with punctured facades that often accompany this urban planning precept, Wiel Arets, the designer of the dominant high-rise and one of the six blocks, proposed a neutral, transparent building envelope (see p. 686ff). To afford passers-by and residents who live opposite the building a bit of a domestic atmosphere, he developed a solution in which curtains become a key design element. A reinterpretation of the closed-cavity facade, these hermetically sealed, highly insulated elements are the result of an intensive series of tests: air that has been rid of moisture is pumped through the interstitial space. In contrast to double-skin facades with vents admitting ambient air, here no dirt or dust can penetrate the elements, and condensation cannot form in the interstitial space. Accordingly, the glass surfaces lining the interstitial space do not have to be cleaned, and the reflectance of the solar protection within it will remain intact for many years to come (see DETAIL 4/2011 p. 404ff).
