This three-storey house is set on a narrow site 3 m wide and 20 m long. Since the occupants go out for many domestic activities, it was possible to create a layout without traditional spatial divisions. The brief required a bright interior and a high degree of privacy. The structure consists of two parallel reinforced concrete walls with round concrete struts between them and a membrane roof spanned over the top. The identical but reversed curves of the walls result in a multiply curved roof form, which in turn determined the position of the cylindrical struts. The fibre-glass membrane affords good natural lighting internally by day. At night, it radiates a diffuse light from within, with the movements of the occupants vaguely visible through the skin.