HOSOYA SCHAEFER Architects (Part I) - Stadtraum HB Baufeld E

Last year the city of Zurich approved a masterplan by Kees Christianse of KCAP for the so called Stadtraum HB, a redevelopment plan of an area behind the main train station (Hauptbahnhof) in the center of Zurich. Most of the buildings belong to the Swiss Federal Railways (SBB) and have been included with some adjacent parts, along the former post building. The total area of 78'000m2 will be transformed into a mixed-use neighboorhood with 400 apartments and approximately 5000 will be working there in future. Additionally some 2000 students of the PHZ (College of Education) will be situated there.
There are nine lots and for each a competition is held. According to the masterplan this current lot "E" (Baufeld E) has to have a minimum of 40% housing and can have a maximum of 40m height.

The image above is one of the projects of the competition for the lot "E" and was designed by HOSOYA SCHAEFER Architects.
They say the following on their website about their project:
"The proposal layers the 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 has been adopted. Each hexagon is supported by three “ribbon columns” that can change orientation relative to the module and move from corner to corner. This allows for smooth adjustments between floors without expensive and inefficient transfer structure. In the front area of the building the ribbon columns run diagonally through the floors and together with vertical tension rods for a large truss supporting the cantilevered front of the building.
The three housing types are separated by roof gardens providing a variety of spaces, public and private, on the upper floors."



I had to share with you the two gorgeous images and on their website you can find more and some plans of the project. Admittedly I have worked in this office for a short while, unfortunately not on this project though. I haven't seen the results of the competition yet and to date I was not able to find out when they are being published, however I think it's worth looking at this project for instance, because it offers a rather fresh approach on the constraints, programatical and formal, that are imposed by the competition or the rather conservative architectural establishment in Zurich. It makes you wonder, how to be expressive without appearing so, in a sense subversive.
This project is based on a cell-like structure that horizontally organizes space (and program) and vertically works to load bearing. The huge cantilever is ARUP approved and creates a covered urban square. Admittedly the images look are seductive, what I can't find out, due to lack of material available on the project so far, is the distribution of the program. I assume the housing is located on the building's south side while the north side, the base and lower parts of the building are offices. From south the building appears to break down into multiple parts while it maintains a visually dominant and representational head on the north side, along with it's public program.
As much as I like the images, the real problem here is, that the surrounding lot's either had or will have competitions for future buildings, but mostly they haven't been defined yet, therefore there is no real context to this project. It is confined to function within strict rules, but imposed by the master plan and it's interior organization.
Final judgment therefore is nearly impossible, however I hope the winning project for the lot "E" in this case will be equally progressive with it's proposed architecture, as this building suggests it might be.

Images © HOSOYA SCHAEFER Architects,
Images and plans: here
Masterplan (PDF in German): here