The Wood | Koshigoe Architects

The Wood is a rebuilt project from an existing 4-story reinforced concrete office building to a 6-story mix-used collective housing with office spaces on the basement, first, and the second floor. The project site is located near the coast, where a concrete building existed on-site, supported by 32 meters deep foundation piles down the soft soil. However, the concrete structure had been planned for its demolition to be rebuilt for this project, and the decision to introduce timber as the structural material brought light to reusing its existing foundation to minimize the carbon footprint.

With the building being demolished, the foundation is left for pile integrity testing to ensure the proper functioning of each pile from any defects, necking, or bulging to be reused. As a result, all the foundation piles met the strength requirements to be reused in this project.

At first, above the foundation rests the office area constructed with steel frames to achieve column-free space; meanwhile, the rest of the building above for the collective housing area is built with cross-laminated timber (CLT) frames to relieve its structural load.

With the combined use of different structural systems and materials, the newly built architecture can increase its floor area from 496 m2 to 705 m2 (1.4 times wider) and significantly reduce its self-weight by 42 tons, in comparison to the former concrete building.

The Wood hopes to provide the idea of repurposing structure and usage of timbers through the scope of sustainability, that the concept is also applicable for other building projects. It hopes to act as a precedent to reduce environmental impact, cost, and design compromises we face daily as architects as we focus more on the future of architectural sustainability.