On a long site beside the smaller Wannsee lake, the task was to restore the villa next to the lake and to complemented it with a new building containing 6 apartments and an underground parking garage. The polygonal building volume is defined by the existing axes on the site and the orientation of the existing villa. Simultaneously the form of the building is expressed in the internal organisation: thus creating generously sized hallways that serve as the central connecting spaces in the apartments. Precise openings in the shell create the entrance area and serve to allow daylight into the staircase. The scaled façade in natural slate emphasises the compact volume through it's characteristic texture. While the south facing façade onto the lake features large openings, the other three façades are simply punctuated. With exception of the underground garage and the lift-shaft, the entire building was constructed from pre-fabricated timber elements. The massive timber floor plates overhang up to 3m as a band of balconies thus offering a private external area in the upper floors. The pollutant-free and permeable system, complemented by the sorption capable surface finishes and manual ventilation, allow a natural regulation of the interior room climate; thereby removing, despite the a completely air-tight construction, the need for mechanical ventilation systems.