The Green Roofed Grass Cave House in Yokohama comprises 97 square meters of space on its v-shaped lot. Since the architect could not build “out”, they built “up”, using a varied split-level design that created rising forms with several exterior patches of green grass. The interior spaces of the Grass Cave are black on all sides, with black-stained wood for walls, ceilings and floors. The architect balanced the dark interior textures by bringing in plenty of exterior light through slatted windows that virtually line the entire interior. Makiko Tsukada’s Grass Cave House was completed last year, a success in both green roof architecture and limited-space construction. It has the feel of a treehouse to us, a playful and imaginative home design that rose to the challenge of its lot. [architect: Makiko Tsukada Architects] [photographer: Shinkenchiku-sha]