tatsuya kawamoto’s asahigaoka house cantilevers over a steep slope in aichi

with a thoughtful structural solution, the house is sensitively perched atop the slope.

kat barandy March 3, 2023 3 min

asahigaoka house: a rational design

Tatsuya Kawamoto + Associates designs its Asahigaoka House as a unique structure built with a timber frame in Aichi, Japan. Located just four meters off the main road, the home opens toward its sloping rear yard, which leads down toward a grassy pond. The unique design of the house was necessary to meet the requirements of the local urban administrative guidelines, which calls for ‘a structure that can be demolished in the future.’

To meet the requirements of the sloping site, a timber structure was used to avoid the need for a semi-underground RC frame, which is typically used in cases such as this. The timber structure allows for the house to be supported by a cantilever, which does not require it to be built down from the road. The house is an example of Kawamoto’s skill in designing unique solutions which adapt to the needs of the local area.

tatsuya kawamoto asahigaoka
images © Takashi Uemura | @takashiuemura_photography

foundations not limited by slopes

Presenting its Asahigaoka House, the architects at Tatsuya Kawamoto + Associates notes the challenges of the sloping site. As the area was difficult to access it was decided that construction vehicles would not enter the premises. To accommodate this, a foundation slab was built with the necessary amount of concrete for weight at a range of five meters from the front road. Steel truss beams were then raised from the slab, enabling the timber frame construction to cantilever an additional five meters from the slab and beyond the incline.

tatsuya kawamoto asahigaoka

shifting the center of gravity

The Asahigaoka House is an impressive structure, designed by Tatsuya Kawamoto + Associates with a meter cantilever. To support this design, a width of fifteen meters is required and a concrete weight is used to secure the house. Meanwhile, the home’s utilities and systems are located along the road-side to shift the center of gravity away from the slope.

The house was then constructed without being buried in the ground, meaning that the equipment piping could be completed near the road instead of using pump-up equipment. This also allowed the one-story building to gain the impressive view that it has today. This cost-effective building method resulted in the Asahigaoka House being a unique and beautiful structure in Aichi, Japan.

tatsuya kawamoto asahigaoka

‘Designing the center of gravity’ simplifies equipment piping, and this construction method suggests similar land and increases the value of land that is difficult to build,’ note the architects. ‘Even if the building needs to be removed due to urban planning in the future, it can be dismantled from the road side in the reverse procedure, and it is a rational construction that can suppress the footprint and leave the original land almost as it is.‘

tatsuya kawamoto asahigaoka