© noshe

The GSW headquarters in Berlin is an assemblage of five building volumes that extend an office tower from the 1950s. A prototype at the time of completion, this project embodies the paradigm of ecological architecture of the 21st century in an exemplary manner.

The building's individual components reflect the characteristic traces of its urban environment's episodic development and make them visible. At street level a gently curved volume redefines the public space and forms a plinth – with its position and height referring to the earlier baroque city. Seen from the east, the slender high-rise slab acts as a backdrop for the existing tower, while emerging with an assertive presence to the west. As a compositional counterpoint, the so called pillbox balances on the eastern end of the plinth, with its height referring to the buildings of the Gründerzeit. This strategy of retrospective integration embeds the previously solitary tower into the urban fabric while acknowledging the historically evolved conglomeration of Berlin as a structural principle.

The slender layout of the new high-rise optimises the use of daylight and ensures cross-ventilation for all offices. Room-high movable screens of perforated metal define the entire west façade and provide effective solar protection. These are fitted in a cavity of the double-façade that functions as a convection shaft allowing natural ventilation on the high-rise floors. An aero-dynamic wind roof enhances this effect. With various shades of pink, orange and red the solar shades make the building recognisable from afar. The individually operable elements respond to daily and seasonal changes, generating new colour compositions again and again. Thus, the west façade illustrates the ecological aspects of the building while, in addition, turning into a perpetually changing kinetic image.

© Reinhard Görner

To understand the history of the site on Kochstrasse one needs to be familiar with the history of Berlin. The city has experienced an extreme variety of different urban ideas since approximately 1700. The Baroque city extensions of northern and southern Friedrichstadt were transformed into the dense “stony Berlin” of the late 19th and early 20th centuries. The bombardments of 1945, the postwar reconstruction in East and West, the incision of the Wall and the International Building Exhibition in the 1980s finally led to the heterogeneous urban structure we found at the start of this project. The simultaneous traces of the various stages of development reveal Friedrichstadt as a rich urban landscape that embodies the social, cultural and political history of this city and its inhabitants.

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Hanns Zischler

The whole site is treated as a single public field on which a number of “mats” mark out significant places. Towards Markgrafenstrasse there is a grove of plane trees; towards Charlottenstrasse lies a timber terrace. The entrance hall was conceived as a covered street.

The low-rise building is clad with a solid and heavy material analogous to the mass of its horizontal volume. The terracotta tiles with their graphite-coloured glazing were developed especially for this project.

© bitterbredt.de

The high-rise façades are the most important elements of the building that serve the low-energy concept. A high degree of transparency allows for maximum daylight. The transmission of heat and light into the interior is controlled through the use of solar shutters and blinds, and the buffer zones of double-layer glass façades on both the east and west sides achieve high insulation values. The porous ventilation openings of the east façade make it a kind of smooth skin, whereas the west façade – with its thickness separated into several layers – resembles a fur. All moveable elements of the façades can be controlled by the individual occupant, but are also operated by a central building management system. This individual control provides for a continuously changing appearance, especially of the west façade.

© Annette Kisling
© bitterbredt.de

With its round figure constructed from a number of radii, the appearance of the “pillbox” depends on the position of the viewer. Its multi-coloured skin supports this impression of a continuously changing object. Looking fat and heavy from the north, when seen from the east or south it balances precariously on the building edge, seemingly defying gravity.

© bitterbredt.de
© Annette Kisling

The entrance hall is a public space from which all parts of the building can be identified and entered. In addition it provides opportunity for exhibitions and other events. In the centre – visible from everywhere –
is the luminous blue reception desk.

The low-rise along Kochstrasse was designed as a building for shops (on the ground floor) and offices (on the first and second floors). The double storey, daylit internal “street” providing access to the office areas lends the building its public character.

© Annette Kisling


  • Extension and renovation of a headquarters building


  • GSW Gemeinnützige Siedlungs- und Wohnungsbau-
    Gesellschaft Berlin mbH


  • gross floor area: 48.000 m²
  • competition: 1991, 1st prize
  • 1995 — 1999


  • MoMA Architecture Collection
  • Bauphysikpreis 2003
  • Benedictus Award 2003
  • Mies van der Rohe Award 2001, shortlist
  • Deutscher Architekturpreis 2001, recognition
  • World Architecture Awards 2001, nomination
  • Architekturpreis Beton 2001, honorable mention
  • Deutscher Fassadenpreis 2001 VHF
  • Architekturpreis 2000, BDA Berlin
  • ar+d Award 2000, special mention
  • RIBA Award 2000
  • Stirling Prize 2000, shortlist

project team