Aki Hamada Architects (AHA) has completed a striking new headquarters building in Fujikawa Town, Yamanashi Prefecture, Japan, that serves as a contemporary architectural representation of the nearby Mount Oboshi. The innovative structure combines traditional Japanese building techniques with cutting-edge computational design methods to create a workspace that harmonizes with its natural surroundings.
The building is strategically positioned on terraced land that offers panoramic views of the Fuji River and Mount Fuji in the distance. The project holds special meaning for the client, whose business focuses on recycling operations. Rather than flattening the natural terrain, the architects drew inspiration from the traditional Kake-zukuri architectural style, which involves timber-based construction that adapts to and follows the natural contours of the landscape.
The most distinctive feature of the building is its revolutionary voxel-based structural system, which was specifically developed for this project. This innovative approach replaces the traditional nuki joinery commonly used in post-and-beam construction with modern metal connections. The system creates a three-dimensional lattice composed of bundled timber beams and columns, drawing inspiration from computational modeling units that allow for flexibility and future expansion possibilities.
The architectural team applied their three-dimensional grid system to accommodate the site's changing elevation levels, extending the Kake-zukuri concept throughout both the foundation and superstructure. The structural system uses groups of four 120-millimeter-square timber pieces that are bundled together to form columns and beams. The number of timber members can be adjusted based on different span requirements and load demands, providing exceptional flexibility in the design.
Advanced precutting techniques enabled precise finishing and connection detailing, which significantly reduced complexity during on-site assembly. This approach draws from the logical principles of reinforced concrete detailing commonly seen in postwar Japanese buildings. The modular design also allows practical features to be integrated directly into the structural framework, including wall panels, equipment, and window frames that are typically treated as separate construction elements.
The building's walls are constructed using panels made from a unique mixture of soil and locally-sourced grass, which slot into the timber lattice like structural infill. This design choice reinforces the building's strong connection to its immediate environment and location. The western facade features fixed windows that are strategically positioned to optimize natural daylight, while deep cantilevered eaves frame spectacular views across the valley toward Mount Fuji.
The ground floor opens onto a terrace and corridor structure beneath the protective lattice canopy. With its lofty ceilings and deep eaves, this covered area functions as a contemporary interpretation of an engawa – a traditional Japanese semi-outdoor buffer zone that mediates between interior and exterior spaces. This porticoed space welcomes visitors in all types of weather conditions and creates a smooth transition between the surrounding landscape and the interior workspace.
Inside the building, the spatial experience is defined by the repeated rhythm of the timber grid system. Structural axes layer across each other throughout the interior, creating varying degrees of enclosure, openness, and visual depth. The first floor is designed to accommodate both staff members and visitors, featuring an open layout with a lobby area and kitchen counter that encourage informal gathering and social interaction.
Vertical circulation between floor levels is anchored by an elegant elliptical spiral staircase. The staircase frame is constructed from steel, and its dimensions were carefully calculated to meet both delivery requirements and the building's floor plan constraints. Suspended within the timber lattice structure, the staircase creates a striking visual impression that the heavy timber frame appears to be floating – a unique hybrid effect that is only possible through the combined structural logic of steel and wood construction. At night, the wooden frame glows softly with interior lighting, while a separate light tower beside the building enhances the overall architectural silhouette.
