Tato Architects / Yo Shimada

House in Kamisawa

Location / Hyogo, Japan
Type / House, Renovation
Family Structure / couple

Design

Design
Tato Architects
Team / Yo Shimada and Keita Kurokoshi

Structure
Takashi Manda Structural Design
Team / Takashi Manda

Construction

Kyowa Techno

Scale

One-storey House
Main Structure – Timber
Site Area 223.33㎡
Building Area 86.57㎡ (38% of max 60% of coverage ratio permission)
Total Floor Area 86.57㎡ (38% of max 200% of floor area ratio permission)
First floor 86.57 ㎡

This project is a refurbishment of a traditional Japanese wooden house. The house was stripped of unnecessary parts and the wooden frames were exposed. By inserting curved walls into the open space, spatial functions were created. An approach similar to the process of designing “Hut with the Arc Wall”, a public toilet in Shodoshima. With the project in Shodoshima the space was defined by a 9mm steel curved wall, which was built under a wooden roof structure, with references to traditional soy sauce factories in the area. The inspiration from cedar barrels of soy sauce was formalized in the curved wall, which showed an aesthetic in its self- supporting structure. The only regrettable thing in the project was the newly built wooden frame. Ideally, it should have been an old house frame from around the area rebuild and reused at the new site. However, a tight schedule did not allow us to spend time to look for a suitable existing building. Since then, we have thought about the distinctive potential of the self-supporting curved wall for dividing spaces in renovation projects.
This project presented an opportunity to test it, commissioned by a couple who owned a well-preserved one-storey wooden house. The existing house contained many rooms in pure Japanese design, which did not seem to be suitable for the young couple starting a new life there.
Unnecessary parts were removed and the exposed structure reinforced where necessary. The curved walls were positioned on the new mortar floor, with floor heating.
The curved wall surrounds guest room, bathroom, and bedroom. While the rest of the space is devoted to kitchen, storage, dining and living spaces. A part of the space above the curved wall is used as a loft.
Due to a limited budget the original idea was to create the walls with 20mm curved plywood. However, once the construction started, it became clear that the curve created by those panels didn’t achieve the desired accuracy and space. It forced us to change the construction method to metal frames of 25mm squared rods sandwiched with curved plywood panels. The exceeding cost were solved by the builder’s effort.
Door and window fittings in the existing house were reused. The interior space of the bathroom was finished with fibre-reinforced polycarbonate, on which a double-layered polycarbonate ceiling was positioned.
The exterior wall was cladded with burnt cedar boards, and some windows were replaced by wooden fittings.
The simple gestures created a new space, while the history of the house remained.