This residential building for a cohousing group in Berlin stands among trees at the edge of a dense group of buildings that were erected for the Prussian army at the end of the 19th century. The ensemble has been occupied by artists and craftspeople since the end of the Second World War, and since the beginning of the 21st century there have been various additions in the form of a large studio building and various rooftop extensions.

Haus 9 has adopted the high ceilings and generous windows from its historic neighbours, as well as the simple, repetitive structure with which they have accommodated a wide variety of uses over some 120 turbulent years. Its exterior massing is a response to the planning regulations that govern the development of the plot. Its interior layout, however – and the consequent façade variations – changes from floor to floor depending on the kind of living and working spaces preferred by individual members of the cohousing group.

The differentiation of the outer skin into exposed concrete and a rendered finish expresses the variation in the amount of load borne by the outer wall, which functions continuously as a supporting structure.

Overall, Haus 9 is a building that addresses a number of parameters: the legal limitations of the site; the adoption of a simple structure that yields maximum flexibility; the provision of robust materials; and a high degree of individuality for each occupant. It does so with a new realism that achieves a consistently strong and elegant appearance.