The total population of Japan has been decreasing since 2010. Such demographic changes influence the demand for wooden housing, which is an important timber consumption sector in Japan. The decrease in total population and increasing tendency for young people to move from rural to metropolitan areas has resulted in a decrease in wooden housing construction in rural areas. As the average number of people per household has decreased (to 2.33 persons, according to the 2015 Population Census of Japan), the total number of wooden houses constructed and their average floor areas have decreased accordingly. The proportion of the population ≥ 65 years of age reached 26.6% in 2015 (Population Census), which was among the highest in national proportions worldwide, and is predicted to further increase with time. As Japanese households continue to decrease in size and their occupants increase in age, the percentage of one- to two-person households is increasing. Some occupants select non-wooden condominiums or other compact dwellings as they increase in age; as a result, decreases are expected in the percentage of homes constructed with wood and in the total floor area of wooden housing for aging people. In summary, the trend in total timber demand for wooden housing will decrease in Japan in the future. Forestry policies relating to domestic timber production in Japan are therefore at a turning point as changes in population demographics affect domestic timber consumption.