This paper describes the relationship between the thermal environment of the encapsulated outer space provided for the detached houses and the environmental behavior of the occupants in summer in Hokkaido. In both the south-facing and north-facing outer space, the concave type suppresses the effect of solar radiation more than the convex type, keeping the room air temperature in the outer space lower. Therefore, the concave occupants frequently opened and closed the openings to adjust the thermal environment, while the convex occupants rarely operated the openings due to overheating of the exterior space.
