OMC Extramuros

Wittfoht architekten, Stuttgart (D)


In August 2008, the WTO initiated a project to renovate and expand the Center William Rappard (CWR), the organization's global headquarters.

Client: Organisation Mondiale du Commerce
Main contractor: Organisation Mondiale du Commerce
Façades: 5 200 m2
Type: New
City: Genève

The third stage ("extramuros", 2010 to end 2012) includes the extension of the CWR by the construction of a separate new building.

On an extraordinary site, on the boundary between town and lake, the new building consists of two elements: the base, connected to the ground, containing the collective installations and the transparent building housing the administration, which seems to float above. The transfer slab forming the glass seal between the office bar and the base allows long overhangs of more than 7 meters and gives its "suspended" appearance to the desk bar.

With this very transparent building, the WTO is open to the public and demonstrates in a democratic way its internal administration from outside. This high transparency is confronted with the high demands of thermal insulation meeting the rules of the Minergie P. label.

The double skin is structured from 570mm large outrigger support brackets, cut out of 20mm steel plates, anchored with 3-D adjustment fasteners and incorporated into the concrete slab.

Folded sheetmetal are fastened between the brackets and serve as a fastener in front of the slab and as support for the aluminum pole-and-beam system of the inner skin.

On the outter side, the head of the brackets are designed to receive the aluminum profiles on which the screens of the outer skin are bonded.

Also the brackets support the steel gratings ensuring maintenance access between the two skins. In the lower part, the brackets support a continuous closure acting as a fire barrier between the floor slabs, as well as the blind boxes.

The natural ventilation, per floor, of the double skin is ensured, in the lower and upper parts, by small continuous horizontal aluminum louvres, including an insect screen.

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