The declining and aging population, as well as the downsizing of households, poses problems for the simultaneous occurrence of vacant houses and the construction of new housing units. The objective of this study was to examine countermeasures for the future occurrence of vacant houses. The relationship between population, households, vacant houses, and newly constructed housing was reviewed according to prefecture, and the occurrence of vacant houses and distribution of newly constructed housing were mapped out. The results revealed that the increase in the number of elderly single-person households is a source of vacant houses, while middle-aged single households tend to promote the construction of new housing due to the lack of housing stock. In Setagaya ward, Tokyo, one of the reasons for the increase in new housing construction may be that many of the elderly single households have old wooden detached houses facing qualitative problems. In Wakayama central city, it was inferred that old, detached houses built for households with children during an economic growth period do not meet the needs of middle-aged single households, due to factors such as age, size, and floor plan, which has promoted vacancy and new construction, resulting in a stagnation of the housing cycle.