Zurich, Switzerland, 2007

“Stadtraum HB”, known today as the “Europaalle”is a development area of the SBB (Swiss Federal Railways) between Zurich’s main station and the Sihlpost (Post Office) based upon a masterplan by Kees Christiaanse.

The proposal layers functions horizontally, resulting in deep floor slabs that are lit with internal courts and light wells. Since all the layers have different spatial and structural requirements, a flexible hexagonal module was adopted. Each hexagon is supported by three “ribbon columns” that can change orientation relative to the module and move from nodeto node. This allows for smooth adjustments between floors without expensive and inefficient transfer structures. In the front area of the building, the ribbon columns run diagonally through the floors. Together with vertical tension rods, these form a large truss supporting the cantilevered front of the building.

The three housing types are located in towers with their own entrances and are separated by roof-top gardens and terraces.