When building a house in a city, due to the smaller sites, don’t you give up size and comfort in exchange for convenience? In the “Tatenoie,” space is used lengthways and sideways by a split-level style, which allows space to extend freely without being restricted by the concept of a three-story house. Nothing is blocked by walls or doors, even the stair hall is integrated as a living space, and there is a large side window even towards the north to let in light, providing physically and psychologically a wide and bright space. The Q factor of 1.86 (calculated based on the show house) has been achieved by external heat insulation and additional heat insulation. Even in the severe insolation of a city, its efficiency means that you can comfortably live with the minimum use of air conditioning, and natural cedar boards are employed on its exterior walls, which refurbishes the concept of urban housing.