Boltshauser Architekten AG

Description

The timber-hybrid high-rise H1 in the new, climate-conscious Zwhatt neighbourhood north of Zurich combines the extensive use of renewable materials with an expressive solar façade. Solid construction was used only where necessary – for the foundations, plinth and staircase – and thanks to the lightness of the timber construction, the dimensions are as slender as possible. Three commercial base storeys with an iconic arcade and prefabricated façade made of rammed earth elements support a distinctive «table» upon which the 21-storey timber-hybrid structure rests. Its Swiss beech columns form a grid for the optimised timber-concrete composite ceilings. Beech frames take the tensile forces, while the thin concrete slabs absorb compressive loads. The structure remains visibly exposed, defining the character of the 156 apartments. Photovoltaic modules, horizontally mounted on all sides, give the façade its unmistakable identity. With bifacial cells, they capture both direct sunlight and the reflection from the modules below, covering nearly half of the building‘s electricity demand. At the same time, they act as a brise-soleil, providing shade for the apartments. Utilising the potential of the load-bearing structure creates spatial diversity. All internal walls can be flexibly arranged along the column grid, enabling a wide range of apartment types that can adapt to future needs. At the heart of the building, a two-storey communal space with clay floor offers an informal meeting point.