The task was to densify a residential area from the 1950s on the outskirts of the city in a contemporary manner and to rehablilitate the existing housing stock without masking ist origins or historical character, at the same time updating the energy infrastructure.
In order to retain the open character of the settlement we opted for an addition of upper stories, a new development which heightened the existing structures. The design parameters for the project entailed updating the energy infrastructure in a way consistent with the settlement’s existing constructive and architectonic character, while at the same time satisfying requirements for sustainable building in the additional stories. The decision for the addition of new upper stories by means of lightweight construc-tion in prefabricated timber paneling also featured the advantage of a relatively compressed construction schedule, and hence minimal noise and disturbance for residents of the existing units. Wall panels and ceiling elements of the new wooden stories were prefabricated at the factory (including mineral wool insulation) and assembled on location. The objective of the façade renovation was to upgrade the existing structures for the sake of longterm rental possibilities: an external layer of insulation and clad in a new layer of exposed brickwork was added tot he existing façades.
Rough, split cedar shingles were used for the façades of the upper stories whose finish features qualities of natural variation. In this way, the lightweight character of the new construction is visible externally; the new stories are set off distinctly from the massive existing structures below, at the same time echoing the surrounding stands of trees in their materiality (treehouses). The majority of the altogether 47 new units are configured as maisonette types. Sticking to the treehouse concept, all of the apartments enjoy spacious roof terraces, and the maisonette apartments have loggias as well. In terms of configuration and dimensions, the plans of the new
apartments are designed to be especially family-friendly, a measure designed to attract younger tenants in the future. In general, the planning measures pursued the objective of doubling the estate’s overall usable area while at the same time halving CO2 emissions.