House in Koganei (SA House) / OFA: A Contemporary Timber Home Framed by Greenery

Located in a quiet suburban neighborhood on the outskirts of Tokyo, House in Koganei, also known as SA House, is a two-story timber residence designed by OFA (OfficeForArchitects) Architectural Design Office. Adjacent to an urban park, the project explores an intimate relationship between domestic life and nature, transforming greenery into a central architectural element rather than a distant backdrop.

From the outset, the client and architect shared a clear vision: to create a home organized around a “tunnel of greenery.” This concept guided not only the spatial organization but also the careful selection of the site. The lush trees of the neighboring park extend visually into the house, drawn inward through a generous north-facing opening that frames the landscape and allows greenery to permeate the interior. Nature becomes an active participant in everyday life, shaping views, light, and atmosphere.

The spatial layout responds thoughtfully to privacy and openness. Private rooms and wet areas are placed on the ground floor, carefully arranged to limit sightlines from neighboring properties. In contrast, the second floor houses the living, dining, and kitchen spaces, elevated to fully capture expansive views of the park canopy. This vertical zoning ensures both privacy and a strong visual connection to the surrounding environment.

Interior spaces are subtly articulated through changes in level rather than walls. A raised white oak platform between the living and dining areas introduces a gentle shift in perspective, while a softly curved wall guides movement through the open plan. A dedicated workspace, positioned at yet another floor height, further enriches the spatial layering. These nuanced level changes choreograph daily life, creating continuity while defining distinct zones within the compact footprint.

Lighting plays a crucial role in shaping the home’s atmosphere. Tunable and dimmable lighting fixtures are installed throughout, allowing residents to adapt the ambiance to different times of day and activities. The fixtures are carefully aligned with the exposed timber structure and white interior surfaces, reinforcing architectural clarity. In circulation areas such as hallways and stairs, sensor-activated lighting enhances convenience and hygiene, reflecting contemporary living needs.

Materiality is restrained yet tactile. The exterior is clad in silver-colored galvanized steel, giving the house a quiet, modern presence within its suburban context. Inside, white-painted surfaces are paired with oak and birch plywood, bringing warmth and natural texture into the living spaces. The roof opens toward the park and is echoed internally through a continuous timber-beam ceiling and gently curving walls, reinforcing a sense of openness and organic flow.

Ultimately, House in Koganei is a refined example of contemporary Japanese residential architecture, where compact design, natural materials, and careful spatial sequencing create a calm, light-filled home. By placing greenery at its core, the project achieves a harmonious balance between architecture and landscape, offering a serene retreat deeply connected to its natural surroundings.

All the photographs are works of Yasuhiro Nakayama