Sustainable buildings for healthier cities: assessing the co-benefits of green buildings in Japan

The results indicate that green and sustainably renovated buildings could yield significant benefits in terms of energy and CO2 reduction, cost savings, and improved health situation for building users. The case study buildings with the best two performances are found to achieve 33% and 26% reduction in energy use intensity, and 38% and 32% reduction in CO2 emissions intensity in comparison to benchmark values. Reduction in energy consumption in the top two buildings corresponds to an energy cost saving of $ 1-1.5 Million per year per building. Furthermore, the top two buildings are found to provide improved healthy environment due to improved indoor and ambient air quality, better thermal comfort and more natural lighting indoors. Making more explicit the multiple benefits of sustainable buildings needs further consideration in this regard. We recommend that the public sector could take key actions to accelerate the number of green buildings including fiscal support, technical assistance and policy reforms.