Regional climate is an important element in architectural design. In particular, from the viewpoint of environmental problems and energy conservation, the passive design that uses natural energy effectively by architectural methods is getting its importance. Thus, the importance of the architectural method is explained. Junzo Yoshimura (1908-1997) designed numerous houses in the postwar Japan, consistently pursued the comfort of the housing. It is assumed that Yo- shimura’s architecture and thought to the environment are projected in works and discourses. This paper aims to clarify the intentionality towards environmental design in Yoshimura’s housing work as seen from the spatial composition of the living room.