Kalkbreite als Idee

Architectural competition

After the building rights were obtained for the Kalkbreite site, working groups were formed to set up the Cooperative itself and to define the space allocation plan for the architectural competition. In this process, the following project objectives were established to accommodate the the approximately 400 future users:

Flexibility / Modularity / Networking

Darstellung Nutzungsmix Kalkbreite

The planned buildings were to be smartly connected, flexible and modular. The space allocation plan of the competition was to be easily adaptable to changing needs or to new uses that may arise up to the start of construction or after occupation. This included a suitable accessibility concept, simple statics and a continuous simple system for home technology.

German only: Explanation of the planned utilization scheme (presentation of the event on 7 February 2008)




The implementation of the Minergie-P-ECO requirements in an inner-city environment with massive buildings and tough economic conditions requires a clear, simple concept and high-quality architecture.

Exterior space

One of the central tasks was to connect the island, which is surrounded by traffic, to the neighborhood. This required integrating innovative functional features to the ground floor and creating an inviting environment. Crucial to the space is its connection to the street level with an outdoor residential area on the terrace above the tram depot, which is also accessible to the neighborhood. Particular importance was attached to the design concept of the terrace as an external residential space, which allows the cooperative to host the quarter.


Last but not least, the whole project was to remain within an affordable framework. The economic requirements required planning that was conceptually outstanding.

Assessment criteria

The architectural competition was evaluated based on the following criteria:

  • Urban planning, architecture, exterior space
  • Functionality (implementation of defined project principles, utilisation concept, spatial structure and open space)
  • Economic efficiency (compliance with overall economic concept)
  • 2000-watt society (Minergie-P-Eco, energy-efficient mobility)

The jury’s evaluation was based on all criteria listed, giving weight to no one particular item. The aim of the project was to integrate the area both structurally and socially into the surrounding urban context to facilitate its emergence as a lively center.


The competition

Wettbewerbsaugsabe vom 3. September 2008 auf dem Kalkbreite-Areal.

The competition opened on 18 July 2008 as a single-stage, international and anonymous architectural contest. The deadline for entries was 14 August 2008. The competition ceremony was held on the Kalkbreite premises on 3 September 2008. 135 teams visited the site and collected their models. From 10 December 2008 on, architectural plans for a total of 54 projects were submitted, and model submissions from 14 January 2009.

The competition judges took four days to examine and assess the submissions. They found all submitted work to be of consistently high quality. The following nine works were then selected for the second round:

  • 1st place/1st prize: “ARPA” project, Müller Sigrist Architekten AG, Zurich
  • 2nd place/2nd prize: Project “ichbinaucheinhaus”, Spoerri Thommen Architekten AG and Peter Habe Architekt, Zurich
  • 3rd place/3rd prize: Project “ROCK THE CASBAH”, ARGE Geibel: Bernath Widmer Architekten, Zurich/ Braendlin Kreiselmayer Architekten GmbH, Zurich/ G. De Pedrini Architekten, Zurich
  • 4th place/4th prize: Project “la vie en rose”, huggenberger fries architekten ag, Zurich
  • 5th place/5th prize: Project “MATHILDA”, Michael Meier and Marius Hug Architekten AG, Zurich
  • 6th place/6th prize: “SERAMIS” project, atelier ww, Zurich
  • 7th place/7th prize: “DINNER FOR ALL” project, Boltshauser Architekten AG, Zurich
  • 8th place/8th prize: “Safari” project, Hauenstein La Roche Schedler Architekten, Zurich
  • 9th place/9th prize: project “STADTDÜNE”, pool architekten, Zurich

On Friday, 27 February 2009 the jury recommended project no. 47, “ARPA” (by the Müller Sigrist Architekten AG, Zurich team) to City Councillor Kathrin Martelli, the head of the Department of Structural Engineering, for further processing. The winning team prevailed against 53 other competitors.