The house is located in one of the most prestigious residential districts of Tokyo. Nevertheless its urban fabric is almost saturated: in fact there’s currently no city-planning code with an adequate degree of sophistication to address the peculiarities of such an exclusive zone. As often occurs in many other towns in Tokyo, the lot is tightly surrounded by the neighbouring buildings, whereas only its northern edge is open onto the public street.
The cubic shape adopted naturally enhances an extensive and rational use of the yet narrow available area. Consistently, the structural elements have been minimized in order to leave broader spaces to the dwelling activities; greater efforts have been put in the design of the shear walls, so that their thickness results the minimum possible.
The steel device here designed consists of two prefab portal frames. Tectonically this spatial frame bears the load of the whole built volume making any column structurally redundant. The outer walls and the roof are clad with steel plates which were sized into conveyable pieces in a workshop; afterwards they were tightly welded to each other to acquire a water-proof membrane-like behaviour. These have been furthermore coated with polyurethane foam: this was sprayed up to a thickness that ensures excellent thermal insulation for both wall and roof.