Loosely composed, closely linked
In the northern Kanto Plain of Japan, in a quiet suburban area where factories and farmland sit side by side, lies a home for three generations. Named “Roof House,” its defining feature is a single roof that gathers several dispersed volumes. The corrugated roof members, the gaps between volumes, and the open margins between the roof and the rooms create a deliberately loose composition. The site, including the forest behind it, measures about 2,000 square meters. The young client, who moved from the city, wished to use the lush greenery as part of daily life while operating a small shop and engaging with neighbors. The building also needed to remain adaptable if the family were to relocate in the future.
The design responds with a semi-open, courtyard-centered layout that embraces the surroundings and supports varied activities. Several volumes are placed in separate positions, with small courtyards formed between them and a thin roof spanning across all. Under the roof, narrow passages, lofts above ceilings, and overlapping rooms sharing large skylights create diverse spatial experiences. The arrangement resembles a small village formed by clustered houses.
The central courtyard faces the forest and functions as an outdoor kitchen or a play area for children. The south-facing entrance court serves as a sheltered approach for visitors. A courtyard enclosed by a north wall is used for everyday tasks such as woodworking or car maintenance. Because the spaces are clearly separated, the house can be used even when the client is not living there. The volume containing bedrooms and bathrooms can be converted into guest accommodation, while the others can operate as a shop or gallery.
For multigenerational living, the architects introduced a stepped domestic grid. The five staggered levels overlap vertically and horizontally, and the resulting continuity of wooden surfaces defines subtle boundaries among family members. Several columns and beams are shifted or omitted, allowing spaces to overlap and creating unexpected transitions.
The divided levels link daily activities—work, rest, play, care—without relying on linear corridors. A resident can move from a semi-basement bedroom to the rooftop terrace without passing through a formal hallway. Small rooms ranging from 4.5 to 7.3 square meters are placed on half-levels. Movable fittings and furniture can be opened, closed, or repositioned so that the rooms function either as extensions of shared areas or as enclosed spaces for sleep or study. The uppermost floor, with its large dining table, serves as the informal center of the home.
Each level is framed by corner windows that bring in light and views from multiple directions. Whether from the front garden, the side yard, the rooftop, or openings in the façade, the surrounding landscape always remains partially visible. This creates a multilayered environment in which the building maintains a close, continuous relationship with its context.
Project: ROOF HOUSE / Location: Tochigi, Japan / Architect(s): TAMADA & WAKIMOTO ARCHITECTS / Project team: Makoto Tamada, Natsuko Wakimoto / Structural engineer: Junichiro Ito / Use: House / Site area: 1,994.98m² / Bldg. area: 160.74m² / Gross floor area: 96.41m² / Completion: 2023.12 / Photograph: ©Kenta Hasegawa (courtesy of the architect), ©TAMADA & WAKIMOTO ARCHITECTS
