Effects of Changes in the Economic Lifespan of Residential Buildings on CO2 Emissions: Evidence from Japan

Residential buildings in Japan have shorter lifespans than those of buildings in other countries. Although it is customary for residential buildings to lose value in the real-estate market when they cross their statutory lifetimes, this rapid reconstruction cycle poses an environmental burden. However, an increase in the proportion of new housing units built according to strict energy-saving standards could have a positive environmental impact. Research on the economic lifetime of buildings remains insufficient, and the trade-offs between the impact of demand in the national housing stock on CO ₂ emissions and the impact of reconstruction on CO ₂ emissions throughout an economic lifetime remain under-researched. Therefore, this study investigates the impact of the economic lifetime of detached wooden residential buildings in Japan on CO ₂ emissions during the manufacturing and use phases. Specifically, it estimates the economic lifetime of detached wooden residential buildings based on real estate transaction data, and assesses the effects of changes in CO ₂ emissions during the manufacturing and use phases by altering the average lifetime. The results show that a shorter economic lifetime of residential buildings significantly contributes to an increase in CO ₂ emissions, whereas extending the lifespan gradually contributes to a decrease, thereby making a strong case for reassessing the statutory useful life of residential buildings in Japan. This study provided evidence that maintaining the economic lifetime of buildings and transitioning to ambitious extensions are crucial aspects of environmental policies.