Exotic prototype - architectural design of an experimental housing project in Freiburg, Germany

Architectural Review, The, April, 1998 by Claudia Kugel

Despite its unorthodox combination of materials and forms, this block of flats in Freiburg is designed to significantly reduce energy consumption.

Of all developed countries, Germany has perhaps most strenuously attempted to embrace ecologically aware design at both a pragmatic and political level. This prototypical terraced house in Freiburg was the outcome of the city's initiative to reduce heating demand in new buildings constructed on council-owned land to one third of normal German standards. Local architect Thomas Spiegelhalter seized upon this prosaic edict as a basis for lyrical, holistic architecture that suggests intriguing new paradigms for development.

Inclined towards the domestic end of the scale, Spiegelhalter's buildings are characterized by the fusion of contemporary technology with quirkily mannerist form-making (for instance the extraordinary family house at Breisach, AR October 1996) and this latest project is no exception. The four-storey block terminates an otherwise unremarkable terrace in Rieselfeld, an outer suburb of Freiburg. The block contains four apartments with studio spaces on the top floor. Plans are a variation on the traditional European tenement model, with external staircases and balconies vigorously animating the basic form.

Industry conflates with biology in an expressive, tectonic composition that alludes to Freiburg's now extinguished industrial base. Lightweight prefabricated building components are interspersed with fragments of timber and glazing, and the organically bulging attic storey is inspired by the shape of pebbles in a nearby gravel pit. Kindergarten colours such as turquoise and pink predominate. The overall effect might appear engagingly ramshackle, but there is a serious side.

Computer simulation was used to optimize the plan form and orientation. A combination of passive solar energy devices, high thermal insulation and efficient thermal storage (in the form of water tanks) helps to reduce energy consumption. On the south-facing elevation, the curved roof supports an angled screen of thermal and photovoltaic panels. The angle of the panels also provides protection from the high summer sun. On the east side, panels of translucent thermal insulation also act as heat absorption units. The external stairs are naturally heated and ventilated through the stack effect. Rainwater collected in an underground tank supplies water for lavatories, pumped around the block by means of photovoltaic energy.

Despite its formal and material unorthodoxies, Spiegelhalter's design incorporates many prototypical elements, variously supported by local and national government agencies; welcome proof of a wider political commitment to the greening of architecture.

Architect

Thomas Spiegelhalter, Freiburg

Structural engineer

Harry Rheinberger

Photographs

F. Busam/Architekturphoto