Abstract
In this paper, we estimated the expected reduction in energy consumption per household as a result of improvements in insulation performance, as per the assumption that the number of new houses should not exceed the range of decrease in the vacancy. We considered the change in insulation performance by type of building according to the relevance rate for the standard of thermal insulation performance by year of construction, and the number of houses required as per the estimates of the number of future households calculated by the municipality. After 2030, given that the number of households will sharply decrease in several municipalities, it is found that the number of newly built houses will be less than about 10% of the present number of households. Thus, it is suggested that the nationwide energy consumption per household of newly built houses as of 2030 will be only 1% less than that in 2010.
To achieve low carbonization in the residential sector, in addition to combining measures such as the improvement of equipment efficiency and the introduction of renewable energy, it is necessary to combine measures such as renovation of existing houses and reduction of houses with low thermal insulation performance.
