The Kalkbreite Cooperative, founded in June 2007, obtained a building permit for the Kalkbreite site from the City of Zurich in September 2007. Not long afterwards, responsible members of the Cooperative began developing the cooperative structures, strengthening the financial foundation and designing the space allocation plan.
In a participatory process, interested Cooperative members worked in groups to define a concept for the architectural competition. The space allocation plan was to be flexible and modular so that it can easily be adapted to future needs. In addition, it was agreed that several units of different sizes and for a range of purposes should be created.
By 18 July 2008, the list of requirements was advanced enough to announce the architectural competition. In February 2009, Müller Sigrist Architekten AG was chosen as the winner of the competition with its ARPA project, which demonstrated that it could best implement the Cooperative’s requirements. At the same time negotiations on the building rights agreement were taking place. On 19 January 2011, the Zurich City Council approves the design plan. In September 2011, the appeal period expires without objections and the building permit becomes legally binding. In January 2012, the first construction machinery is put into operation and construction begins. If all went according to budget and timeline, the residential and commercial spaces could be occupied and inaugurated in August 2014.
On the lower three floors (ground floor, mezzanine, 1st floor), which border on the inside of the tram hall, there are catering and retail areas as well as offices and services. The commercial spaces range between 25m² and 520m² in size and vary from one to three storeys high at different room heights. Some spaces even have galleries.
Social interaction takes place on the terrace floor (2nd floor) where the main entrance is located. This leads to the building’s reception, mailboxes, cafeteria, library and laundromat. To complete the special layout, there are a number of flex meeting rooms as well as a guesthouse.
The upper four floors are reserved for the residents. Bases on the input from the Cooperative participatory process, the housing arrangement was designed in relation to the competition tendering as follows:
- An increased number of 2-3 room apartments at the expense of the large apartments.
- The smallest apartments combined into residential clusters with shared living rooms.