Increasing the height of a housing block is an effective means of creating additional living space in an existing structure. This strategy has proved to be an individual response to the acute housing shortage in many large cities. 
With the present penthouse in Neukölln, Berlin, Atelier Zafari has demonstrated the manifold potential of this method of increasing housing density. The vertical extension of a ­seven-storey block of flats from the 1970s adds a further dwelling unit.