Designed over a period of six months and then built in the same amount of time, working in collaboration with engineer Masahiro Ikeda, this house is the expression of a client’s childhood dream of climbing onto the roof of his house. The clients, who lived in a traditional, single-family home had gotten used to taking their week end meals on the tile roof. They had set up the necessary equipment for dining on this tight space of approximately 6 m², which they accessed with difficulty via a small window. Tezuka architects, taking into account the clients’ desire, radicalized the concept to the point of obtaining a house that can be virtually reduced to its roof. Extending over a single level, all the rooms are protected by a broad overarching cover, with a single, 10-degree slope, parallel to the ground – unlike the surrounding houses with two or four slopes. Here, the roof is transformed into a terrace that can be utilized throughout the year: installation of chairs, a table, an outdoor kitchen, a shower and a stove, all adapted to the inclined roof, transform the roof into a full-fledged living area, in summer and winter. To access this new space totally open to the landscape, each member of the family has a ladder and a passageway adapted to each one, which also function as light wells. On this new floor covered with anti-skid wooden slats, one can lie down and contemplate the view of Mount Kobo, play or eat. This roof, which has increased the inhabitable surface by 100 m², is equipped with a freestanding concrete wall that preserves the family’s privacy and protects the dining area from the wind.