ABSTRACT
Introduction This is the new headquarters building for Gemeinnutzige Siedlungs und Wohnungsbaugesellschaft, one of the largest providers of social housing in Berlin. They originally occupied a complex of buildings which comprised a 17-storey office building, together with a three-storey low block surmounted by a threestorey drum. In 1990-91 they decided to hold a design competition to provide themselves with additional office space. Sauerbruch Hutton won the competition, proposing a slender 22-storey tower linked to the existing tower. The building was completed in September 1999.
