Of course, the existing building was so much more than just an underground parking garage. This house, which was built in Grunewald in 2014, is staggered with its three storeys from street level down to Hundekehlesee and is therefore barely visible from the street. Nevertheless, the underground parking garage built into the slope with a car elevator dominated the first impression on our first visit. The very sober, orthogonal façade with stainless steel railings was also more reminiscent of an office building. Everything seemed quite austere. This gave rise to the idea of incorporating the softness of flowing water and bringing this completely different design language into the building. The staircase between the garden level and the mezzanine level, which blocked the view of the lake, was moved to the part of the building behind the solid load-bearing central wall. Cut-outs in this load-bearing wall opened up rooms on the garden level, which were originally not naturally lit, to create a light-flooded living space. The former cut-out in the ceiling of the staircase became an air space connecting the garden level and the mezzanine floor. Parts of the former underground car park have been converted into a sports and spa area. The former car elevator shaft has been transformed into a large skylight that now provides natural light to the basement. The garden façade was only minimally altered, but essential for the use of the house: A large fixed glazing on the garden level was replaced with a large sliding door. A large sliding door was replaced by two smaller elements to provide more effective ventilation for the rooms on the mezzanine floor. The contrast between the “round and the angular” runs through the entire design and served as a common thread for the selection of details such as tile patterns, lights and furniture handles.