Office of the President of the Federal Republic of Germany in Berlin
The additional administrative space required in the competition brief was provided in an independent building to one side of the existing presidential office in Bellevue Palace. Without sacrificing the advantages of a directional rectilinear layout, the elliptical form allowed a better integration of the building into the landscape. This is also facilitated by the dark, polished stone (Nero Impala) façade, which reflects the changing forms of the large deciduous trees of the park. All offices are located in the closed outer ellipse of the building and enjoy a view of the park. At the centre is an independent structure containing special rooms and ancillary spaces, and linked by bridges to the internal access galleries. The strictly articulated, introverted space between the two sections of the building is enlivened by the effects of light and shadow created by the glazed roof. The solid form of construction, the design of the windows and the natural ventilation system obviated the need for mechanical air-conditioning in the ring of offices. In summer, the outer windows can be opened, with sunshading provided by louvre blinds between the two layers of fenestration. Night-time ventilation is possible by tipping the inner casement. In winter, when both layers of fenestration are closed, solar heat gains occur through the windows in the offices and through the glazed roof over the hall. Air-intake ducts allow a natural ventilation of the hall, with exhaust air extracted via openings beneath the roof.