Spatial growth and urban densities in China - trends and impacts on economic and energy efficiency

Chinese cities are hovering in their average density close to the threshold of 5000 inhabitant/km2, with highly dense congested cores and a vast suburban expansion where the suburban area has been multiplied by 1.8 every 10 years for the last 2 decades. If the present trends continue, Chinese suburban density will be around 2500 inhabitant/km2 in 2030, with suburbs 36 times bigger in surface than the core, as the Shanghai case exemplifies. It would notably lead to a tripling of energy demand for transportation and contribute to increasing the infrastructure costs per capita. China needs an urgent and ambitious shift toward infill urban development to avoid the current trend of edge and leapfrog growth that feeds de-densification and urban sprawl. National and local policies must promote and foster compact urban development and high levels of articulated density: high residential density, high job density, neighbourhood scale mixed use, and high density of urban amenities to improve accessibility.