In Saga Prefecture, Japan, Amane Architecture has realised OND Sauna, a public bathhouse that places timber construction at the centre of its architectural concept. Designed as part of ONDPARK, a wider development for exercise, dining and cultural programmes, the project demonstrates how natural materials and spatial organisation can be combined in a contemporary wellness setting.

Spatial Design and Community

The project addresses the particularities of Japanese sauna culture, where public bathing is less focused on direct social interaction than in other regions. OND Sauna responds by arranging vertical timber walls in irregular sequences that allow controlled sightlines and varied degrees of intimacy. This approach creates what the architects describe as a sociopetal structure: a layout that enables shared experience while maintaining personal space.

Use of Cross-Laminated Timber

A key feature of the design is the use of cross-laminated timber (CLT). The building employs 150 mm CLT floorboards in a modular system that eliminates beams, reducing the number of non-perpendicular joints and simplifying construction. This method improves efficiency on site and illustrates how CLT can contribute to both structural rationality and reduced material waste. The use of domestic wood also ties the project to local resources and emphasises timber as a renewable building material.

Connection with the Forest

OND Sauna is situated within a natural park, and the building’s organisation is designed to frame and extend views into the surrounding forest. Openings in the walls allow filtered perspectives, while the circulation route spirals upwards to an outdoor bathing area on the roof. The vertical rhythm of the exterior walls refers to the growth of the trees and reinforces the relationship between architecture and landscape.

Architectural Approach

Amane Architecture, led by Taro Shimokawa, frequently works with natural materials such as timber. The practice aims to create spaces that are functional in everyday use while maintaining a distinct connection to context and material expression. OND Sauna reflects this approach by combining a rational timber structure with sensitivity to social behaviour and natural surroundings.

Source: Amane Architecture via V2com
Photos: Akinobu Kawabe (helico) / Kazuyoshi Miyamoto (fusion graphic)