Akira Koyama / Key Operation Inc.

This housing complex consists of 9 one-room units measuring approximately 20㎡and 3 units measuring approximately 30㎡. The L-shaped design of the building as a whole secures an open space between the entryway and street, while two tree-shaped voids inside the building allow for a compact arrangement of balconies and walkways between units. The voids provide ventilation because they are oriented towards gaps in the densely-developed residential neighborhood surrounding the building; the chimney effect produced by the tall, tree-shaped voides further enhances air circulation. Light also pours in through the top of the voids. The units have a diverse range of floor plans, including I, L, C, T, and other shapes that wrap around the voids. Standout features of the exterior include concrete poured in larch plywood formwork and hot-dip galvanized metal window frames.