This narrow house for a couple and their little child is located in a
densely built-up area of Osaka , Japan. The building site is only 3.4×13.0m. To make full use of it, the house is framed in exposed structural steel , coverd with thin fire – resistant adiabatic panels ,and contains six floors with split levels. Lv.1 (basement level) is a bedroom , Lv.2(ground level) is a garage , Lv.3 is for the little girl , Lv.4 is a living space , Lv.5 is a bathroom ,and Lv.6 is a roof terrace. The expanded metal stair connects each floors and spreads the sun light inside. In this house , they are living like birds swinging from branch to branch .