For one of his earliest commissions, Calatrava was asked to create a protruding roof for this post office building, designed by the Lucerne architects Amman and Bauman and situated adjacent to the Lucerne Railway Station, opposite the Cultural and Congress Center. The steel structure, which should be seen as a sculptural addition to the facade, comprises two parts. The first is an aerodynamic, cantilevered rib-and-spar structure, which stretches the full 100 meters to define the outer edge of the protruding roof. The second is a glazed area, which allows direct daylight onto the work area.
Pinned to brackets fixed to the concrete frame, the roof extends 10.9 meters from the building. Through the open geometry of this cantilevered device, the entire roof structure not only appears light, but the continuity of the existing facade is also preserved. An additional effect of the glazing is the dynamism imparted to the canopy. This trait is reinforced by the suspension of the wing away from the facade. The underside of the shaped box is clad in aluminium, while the top is covered in corrugated sheet. The torsion tube is cantilevered off the facade on the one hand by a series of welded I-beam compression members, and on the other by tension members that take the form of elongated triangles filled with perforated aluminium sheet. The proposed maintenance cradle was not realized, and a mesh grate over the gutter now serves as a walkway for cleaners.
1983 - 1985