Ōimachi House
Located just five minutes from Oimachi Station, this 73-year-old wooden house has been transformed into a contemporary workspace through a renovation that balances clarity, preservation, and adaptability. The building is part of a dense cluster of postwar wooden structures situated behind the area's more prominent commercial and mid-rise office developments. This house, once a typical home in that quieter layer of the city, now takes on a new role as a functional and character-rich office.
The entrance was redesigned with a new door and exterior wall finish, offering a clean surface where signage can be installed—making its commercial use immediately legible from the outside. Just beyond the door, a new partition was added to provide visual and spatial separation between the entry and the main working area, offering a layer of privacy appropriate for client visits or meetings. A wall-mounted coat rack and shelving unit are positioned here, designed with a softness and informality that contrast with typical office storage.
On the first floor, all existing flooring—previously a faux-wood PVC—was replaced with grey, durable finish throughout. A single line of orange tiles now stretches from the entrance toward the back of the space, passing through the toilet and leading to the unit bath. Overhead, a corresponding strip of ceiling panels with integrated downlights subtly traces the same line, giving orientation and rhythm to the otherwise open space.
In the area that once housed a tatami room, a compact stainless-steel kitchen has been installed. Designed with flexibility in mind, it features a movable island and plug-in IH cooktop, making it easy to adapt for team lunches, workshops, or more casual use. Electrical outlets have been positioned thoughtfully throughout the space, based on projected desk and equipment placement. Curtain rails are integrated into the walls to allow visual control while keeping the original aluminum window sashes discreetly hidden.
The second floor was entirely opened up by removing the ceiling and non-structural partitions. The exposed roof structure reveals the original timber framework, while new insulation and a newly built roof were added above to ensure comfort and energy performance without sacrificing vertical openness. A symbolic ornament from the original jōtōshiki (ridgepole-raising ceremony) was left in place—preserving a subtle but meaningful historical element. The design avoids unnecessary visual noise, instead allowing reused doors, muted wall colors, and a single orange pendant light to quietly define the mood.
The renovation respects the contrast between the new and the existing. The floors of both levels and the roof have been rebuilt, while traces of the former ceilings and wall finishes remain visible beneath or beside these new surfaces. This duality becomes a design principle: the visible "underside" of the new architecture serves as a quiet reminder of what came before. The project’s spatial identity is shaped by this layered relationship between past and present.
By clearly defining new functions without overwhelming the building’s inherited character, the Oimachi Office demonstrates how Tokyo’s aging wooden homes can continue to serve meaningful roles in the urban landscape—especially in places where high-rise and human-scale structures stand side by side.
