prewood

Given the construction constraints of a narrow lot, the structure was modularized to balance construction efficiency and reusability, and the modular composition is expressed on the exterior. Toilets and stairs were consolidated at the front, and part of the second floor was made a split level to maximize seating area; the resulting “2.5th floor” is a semi-private room for dinners and meetings. Built as quasi-fire-resistant construction in a fire prevention district, it uses cedar boards on the exterior, plaster inside, and exposed CLT ceilings designed for char depth.

A two-story timber restaurant building with a total floor area of 74.43 m², on a 52.62 m² lot in Nihonbashi Kayabacho. The facade, which expresses the composition of the wall panels as is, faces the street between the surrounding buildings.

The exterior walls were divided into 41 panels built with conventional timber framing, which were assembled flat before being erected. Metal connectors were reduced in favor of screw connections: about 2,500 screws were placed in 3D CAD so that none would clash, and 50 3D-printed jigs were made so that craftspeople could drive each screw at the specified angle.

All connections are screwed, so the panels can be dismantled and reassembled by removing the screws. Structural design was by Arup, and construction proceeded from the 3D model.

The study began with a combination of zigzag walls and DLT slabs, comparing options with different vertex positions and degrees of subdivision. After a cost review, it was decided to build the exterior wall panels with conventional framing instead of CLT, and the exterior design was finalized in February 2025.