A striking new residential project in suburban Tokyo demonstrates how architecture can create a seamless dialogue between interior spaces and the natural environment. The SA House, located in Koganei and designed by the OFA (OfficeForArchitects) Architectural Design Office, represents a 2025 completion that centers its design philosophy around what the architects describe as a "tunnel of greenery." This innovative two-story timber residence, covering 95 square meters, transforms a standard suburban lot into a thoughtfully choreographed sequence of spaces that prioritize views of an adjacent urban park and integrate nature as a core architectural element.
The project's genesis began with a shared vision between client and architect to place a verdant passage at the heart of daily life. This conceptual starting point influenced the very site selection process, as the design team sought a location where mature vegetation could become an integral architectural element rather than merely a backdrop. The chosen property benefits from lush park trees extending to its northern boundary, allowing the architects to incorporate generous openings that frame the landscape and draw natural views deep into the home's interior. This integration of greenery serves as the principal architectural theme, informing decisions about orientation, fenestration, and spatial flow throughout the design.
On the ground floor, private rooms and service areas are arranged with careful consideration of external sightlines from neighboring properties, maintaining privacy while maximizing natural light. The architects strategically positioned bedrooms, bathrooms, and utility spaces to create a solid base that supports the more open public zones above. In response to the client's specific request, the lighting design features tunable and dimmable fixtures throughout both floors, allowing the ambiance to shift with the time of day and seasons. Fixture positions were meticulously coordinated to harmonize with the exposed timber structure and white-painted interior finishes, creating a cohesive visual language that celebrates the materiality of the construction while providing functional illumination.
The second floor concentrates the primary living functions—living, dining, and kitchen—in a single open-plan arrangement that fully embraces views of the adjacent park. Between the living and dining areas, a raised platform crafted from white oak creates a subtle change in floor level that defines spatial zones without enclosing them. This level change, combined with a gently curving wall, choreographs a deliberate sequence of spaces and reinforces a sense of continuity within the open plan. A dedicated workspace for the homeowner, set at yet another floor level, further enriches the spatial layering and fosters a fluid relationship between the exterior environment, the communal living space, and the private work area.
Material selection plays a crucial role in the home's aesthetic and sensory experience. The exterior is clad in silver-colored galvanized steel that provides durability while reflecting the surrounding environment and requiring minimal maintenance. Inside, white-painted surfaces combine with oak and birch plywood finishes to create a restrained yet warm palette that brings natural tactility into the living environment. The roof form opens toward the park and is echoed internally by a continuous timber-beam ceiling and softly curving walls. Together, these organic elements contribute to a spatial expression where the architecture actively seeks a close and harmonious relationship with its natural context, blurring the boundaries between built and unbuilt space.
The SA House represents a thoughtful response to the challenges of suburban residential design in dense urban environments like Tokyo. By prioritizing the integration of nature and creating varied spatial experiences within a modest footprint, OFA demonstrates how architectural ingenuity can transform limitations into opportunities. The project's success lies in its ability to make a compact home feel expansive through careful framing of views, manipulation of floor levels, and a cohesive material strategy that connects occupants to the changing seasons and daily rhythms of the adjacent parkland. This approach offers a model for how future residential architecture can maintain human connection to nature even within increasingly developed urban settings.
