Designed in Shigaraki-cho, Koka, Shiga Prefecture, which is well known for its ceramics production, this building is the office of a construction company that was established in this area. Cross laminated timber (CLT) panels—sourced from Okayama Prefecture—was used both structurally and as a finishing material. One hundred per cent Biwako timber—a certified Shiga Prefecture product—was used as the raw material in the production of the CLT panels.
This project was launched with the aim of fostering large-scale circulation—the cultivation of the waters of Lake Biwa throughCLT’s effective use of forestry resources, the invigoration of the overall forestry industry, and also bringing prosperity to the mountains of Shiga Prefecture.
Based on the three concepts of showing the cross section of CLT, giving a finish with CLT and using CLT in curves, the architect explored ways to utilise CLT’s distinctive nature. By using an arch-shaped continuous frame made possible with CLT panels, the building has been given a vault-like, gentle and warm working space.
In addition, with the building’s continuous arch, the architect aimed to make it suggestive of the original landscape with the climbing kiln in Shigaraki—which is famous as a town of ceramics—so that the local residents can find the building appealing.
The owner requested to leave the CLT panels exposed as much as possible for this project. Firstly, for the inner wall, one side of the CLT panels were left exposed and a plank of Japanese cedar was added on the back side to create a double-layered wall to hide the installation wiring. This double-layered wall not only hides the wiring, but also serves a design purpose in hiding the metal joint element between CLT panels. The CLT panels were left exposed on the portion of the wall below the eaves of the outer wall, but hinoki cypress planks were affixed onto the exterior of the CLT panels in areas that come in direct contact with rain in order to increase weather resistance. The CLT panels were also left exposed on the floor of the terrace and entrance areas. However, as intense aging over time is anticipated for these areas, relatively smaller 2-square-metre panels were used to make replacements easier in the future.
Project Name: Santo CLT Office
Location: Shiga Prefecture, Japan
Completion Date: March 2017
Site Area: 705.8 square metres
Gross Floor Area: 138.8 square metres
Number of Rooms: 2
Building Height: 4.1 metres
Client/Owner: Santo Co Ltd
Architecture Firm: Junichi Kato & Associates
Principal Architect: Junichi Kato
Main Contractor: Sakata Co Ltd
Mechanical & Electrical Engineers: Uenichi Co Ltd; Kumagai Co Ltd
Civil & Structural Engineer: Timber Engineering Construction Co Ltd
Images: Kei Sugino