A timber structure right in the middle of Prenzlauer Berg – on top of that, in the dense urban fabric – is in any event something out of the ordinary and not permissible by the building code at this height. With an elaborate fire-protection concept – followed by a lengthy negotiation phase – the architects were ultimately able to convince the authorities of the project’s practicability. The free-standing, unenclosed concrete stairway turned out to be a decided advantage, because it constitutes a readily accessible, smoke-free escape route (see p. 1304ff.But the decision to set the stairway apart from the apartment building had not originated as part of the fire-protection engineering, but was a major component of the design concept from the start, ensuring that the apartments receive daylight from three sides. In addition to its front facade and the courtyard facade, the building has a third facade. Separating the main structure from the stairway allowed more flexibility in the design of the floor plans: It was possible to eliminate interior load-bearing walls. Therefore, each of the clients could choose how to organize the floor plan – the only requisites were the two concrete shafts for installations. The overall circulation system incorporates variety, too: Some apartments are directly hooked up to the stairway via a short bridge, while others have a spacious threshold doing double-duty as a terrace.
