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

High concentrations of people and economic activities in urban areas have strengthened the links between cities, health and the environment. Cities are not only responsible for environmental and health problems but also they hold the key for a greener economy and a sustainable future. Urban built environment is a policy field where appropriate policies and actions could yield significant human and ecological benefits. Among different elements of urban built environment, buildings deserve particular attention due to their large contribution to environmental and health problems. The concept of sustainable (green) building is a recent response to address the problems that stem from the building sector. However, the widespread implementation of the concept is hindered by significant challenges. This paper argues that manifestation of multiple benefits that sustainable buildings deliver could help overcome some of these challenges. The paper presents the extent to which green buildings could generate co-benefits, and underlines the opportunities and barriers to push green building agenda forward. 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. (C) 2016 Elsevier Ltd. All rights reserved.