How to while utilizing the merit of the existing building, a project that aims to improve the heat insulating effect at a low cost. Renovation before the office environment is cold air from the window enters in winter, the blind to receive the strong sunlight in summer has been a deadline closed space How dropped to a new space an existing continuous window was only negative element, I thought how they are allowed to change to a positive direction. The thinking and lighting adjustment to increase the air-conditioning efficiency in priority during winter, can buffer space that window is continuous between the external and the internal space, and the people who work the place is in the office, and places such as tying the other person the so as to constitute the top of the nested volume to ensure the strength of a person can ride, and so can be used as a storeroom.