The client requested us to design a house made of reinforced concrete on a site in a lively neighborhood near a station and a busy commercial district. However, the ground condition around this area is very poor and soft. If building a 3-story reinforced concrete building, we would need to install pile foundations driven deep into the support layer, which would be unrealistic due to the large construction cost. In order to decrease the weight of the building, we adopted the composite structural system comprised of reinforced exterior concrete walls and conventional timber infill including interior walls and floors.
The reinforced concrete outer shell (exterior walls) bears all horizontal loads including seismic and wind loads, allowing for free planning of infill components without bearing walls.
We installed “cranks” on vertical outer walls to prevent deformation of the reinforced concrete outer shell caused by a lack of slabs or beams in the middle level and to make it structurally stable.
These “cranks” are structural members, but they are also utilized as ribs supporting wooden beams, light shelves, counters, benches, eaves and for other purposes.
The outer shell embraces and integrates the residential space and the exterior space including terraces and courts. The “cranks” continue throughout the interior and exterior, creating a sense of ample spatial continuity. At the same time, the crank-shaped walls create a new expression of reinforced concrete architecture, and accentuate the space and the building with patterns of deep shadows..