Sustainability and the Built Environment: The Role of Durability

A sustainable city combines stable long-term economic growth with a resilient ecological system. It is also a region of social sustainability with low levels of spatial segregation of different socio-economic groups. Spatial inclusion primarily involves provision of equalized city-wide access to territorial public goods. High durability of physical networks and buildings facilitates economic, environmental and social sustainability. This study shows that durability varies considerably between Asian, European and North American cities, with mean life expectancies of buildings that range from below 20 years in Chinese cities to over 100 years in European cities such as Paris. Urban planning principles that focus on the slow and steady expansion of accessibility and density within a durable built environment are consistent with general economic equilibria, while avoiding the pitfalls of political planning of the markets for private goods.