Due to Imai’s narrow footprint, Katsutoshi Sasaki + Associates’ carefully controlled and directed the use of natural light. Smaller single-occupancy rooms such as bedrooms receive less sunlight in order to reserve light for the larger and airy communal areas. To make the most of the small living space, many rooms were designed for flexible programming such as a long corridor that stretches between the living room and master bedroom that doubles as a children’s play space and study hall. “By overlapping multiple uses on one space, efficiency of floor space is improved,” say the architects. “Corridor as desk space, inner garden as dining or guest room, and so on.”
In lieu of a garden, the architects added a small indoor patio with a large glazed wall for the family to grow indoor plants. A roof terrace also provides additional space for plants and is lined with large glazed panels to help bring natural light and ventilation into the living room below. Light wooden stairs connect the different levels of the house, from the entrance to the double-height living room to the roof terrace and sun deck above.