Japanese architecture firm Hugo Kohno Architects has recently completed a residential project from reinforced concrete
The client asked the practice to design a house made of reinforced concrete on a site in a lively neighbourhood near a station and a busy commercial district. However, the ground condition around this area was very poor, and if a 3-storey reinforced concrete building was to be built on the site, extensive and costly pile foundations would need to be driven into the ground.
To counter this problem, the architects adopted a composite structural system comprised of reinforced exterior concrete walls and conventional timber infill including interior walls and floors.
The reinforced concrete outer shell bears all horizontal loads including seismic and wind loads, allowing for free planning of infill components without bearing walls. “Cranks” (stepped sections) were installed on vertical outer walls to prevent deformation of the reinforced concrete caused by a lack of slabs or beams in the middle level and to make it structurally stable.
The "cranks" are structural members, but they are also utilised as ribs supporting wooden beams, light shelves, counters, benches, eaves and for other purposes. The outer shell embraces and integrates the residential space, while the exterior space includes terraces and courts.
The "cranks" continue throughout the interior and exterior, creating a sense of 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.