Mitsutomo Matsunami took the task to fit an apartment block onto a 110m2 lot and at the same time to not cross a very tight budget as a challenge. His idea was to break away from the uniform stereotype of residential blocks of flats, with windows stacked neatly next to each other. Katayama Apartment consists of seven floors above ground, which are divided into ten flats accessible by an elevator and stairs on the northern side. Several of the flats are in designed in a high-ceiling maisonette style covering 2 floors, which is clearly visible on the southern facade.
The design of the facade itself also takes fire safety into account, which was an additional challange in the development, resulting into an original, variable pattern of the balconies, which still abides the emergency evacuation standards. The life and motion of the interior are projected outwards by the facade, in order to emit the liveliness and energy onto the old fashioned monotonous neighbourhood of Katayama in Osaka. The exterior colours are in a strict black and white combination to enhance the presence of rational minimalism in contrast to the bland beige grey buildings around.