Sustainable Urban Redevelopment Conditions and Condominium Rebuilding: A Case Study of Tokyo, Japan

As cities worldwide face ageing building stock, declining populations, and sustainability imperatives, rebuilding existing multiunit housing, especially condominiums, has been identified as a critical urban challenge. High-density cities must balance liveability and the regeneration of structurally ageing yet well-located residential assets. Tokyo exemplifies this situation, with more than 14 million residents and a vast stock of ageing condominiums built during Japan’s postwar expansion. This study examines condominium rebuilding in Tokyo by analysing 150 redevelopment cases between 1986 and 2024, including those under the Condominium Rebuilding Facilitation Act, focusing on years since original construction, project scale, applied business models, and proximity to railway stations. Findings indicate that rebuilding occurs in structures around 47 years old and near high-accessibility transit nodes, with projects averaging 85 units and featuring diverse development models. Furthermore, regression modelling is used to estimate future demand for rebuilding condominiums in Tokyo by 2050. Results suggest that about 235,000 units—or 20% of the projected ageing stock—could be rebuilt, with demand expected even in suburban areas such as Tama. These insights inform Tokyo policy strategies and provide transferable knowledge for cities worldwide to address the converging challenges of demographic decline, ageing housing stock, and sustainable redevelopment.