The aim of this paper is to show the state of the construction of three-story detached houses in Tokyo Metropolitan Area, and provide the data for studying the desirable way of controlling the construction of three-story detached houses at densely built-up areas with small housing lots. First, it summarizes the passage of the mitigation about constructing three-story wooden houses. Second, it analyzes the macro trend of the construction of three-story detached houses in the cities, wards, towns and villages of Tokyo, Saitama, Chiba and Kanagawa Prefectures. And then, it is cleared that the percentage of three-story detached houses is higher where the rate of small housing lots under 100m2 is higher and the area with use zoning for low rise residential buildings is smaller, but at the same time, three-story detached houses are also increasing recently where the area with use zoning for low rise residential buildings is not small, because of the mitigation about constructing three-story wooden houses.
