Resource and the environmental burdens of excessive construction in China's urban housing sector

Abstract

In China's complex urbanization process, excessive construction has led to large-scale housing vacancies, hindering the development of low-carbon and sustainable cities. This study proposes a three-layer accounting framework based on dynamic Material Flow Analysis (MFA). The framework innovatively identifies and quantifies the impacts of excessive construction on urban building metabolism and systematically evaluates five vacant housing disposal strategies across multiple dimensions, focusing on material consumption, land use, and carbon emissions. The results indicate that the excessive vacant housing stock in Chinese cities reached approximately 3986 km² in 2024. If excessive vacant stock can be effectively revitalized, between 2025–2060, the total material consumption could be reduced by up to 3873 Mt and carbon emissions by 1241 Mt. However, historical excessive construction has significantly diminished the metabolic efficiency of urban housing, and even under the optimal strategy (revitalization), it remains challenging to fully offset the excessive resource inputs already incurred. Throughout the entire urban housing development period (2000–2060), conservative estimates suggest that at least 2200 Mt of ineffective material input and 1395 Mt of additional carbon emissions will be generated. Given that the existing housing stock is theoretically sufficient to meet demand through 2030, it is imperative for China to curb further expansion of the housing stock while actively advancing the revitalization of existing vacant units. Furthermore, with housing demand expected to peak around 2050, a large volume of vacant stock beyond that point may render revitalization strategies ineffective, necessitating more aggressive interventions such as proactive demolition.