In dense urban environments where space is limited and construction is complex, the Prewood project by VUILD in Tokyo offers a new approach to circular timber architecture. Built on an ultra-narrow site in Nihonbashi Kayabacho, the project shows how modular design and material efficiency can reshape small-scale urban buildings.

Designing For Disassembly And Circularity

VUILD designed Prewood as a demountable timber structure. The team planned for disassembly, relocation and reuse from the start. The building consists of stacked, box-like modules made from cedar and cross-laminated timber (CLT). Each module can be dismantled and reused individually.

This modular approach reduces environmental impact across the building’s lifecycle. It also lowers embodied carbon and prevents future waste. Prefabricated timber elements minimise material waste and improve production accuracy.

Digital Fabrication And Efficient Assembly

The project combines CNC fabrication with digital design tools. Designers mapped around 2,500 screw positions and integrated them into pre-cut timber components. During assembly, workers used custom 3D printed guides to place screws with high precision.

This method speeds up construction. The team completed the main structure in just two days. Scaffolding technicians carried out the assembly, which reduced the need for specialised carpentry. This shows the potential of labour-efficient timber systems.

Material Strategy And Fire-Safe Timber Design

The project sits in a strict fire-regulated zone. The design team adapted timber construction to meet safety standards while keeping emissions low.

The building uses cedar façade panels, exposed CLT ceilings and plaster interiors. The team selected vertical grain, knot-free timber to increase durability. The façade allows natural weathering and includes ventilation gaps. Metal elements protect vulnerable end grains and extend the material’s lifespan without chemical treatments.

Rethinking Urban Timber Architecture

Prewood introduces a new model for compact and adaptable urban buildings. The modular system allows flexible use, while split-level interiors maximise space on a small footprint.

Source: VUILD / Gooood Design Network
Images: VUILD / Tomoyuki Kusunose / Hayato Kurob