From Density to Efficiency: Exploring Urban Building Use Efficiency in 35 Large Chinese Cities

Efficient urban land use is essential for sustainable urban growth. However, the efficiency of buildings in carrying urban functions remains poorly understood. A comprehensive approach for measuring urban building use efficiency (UBUE) and marginal effect was developed by quantifying the relationship between building volume and urban function. The intensity of urban function was calculated from nighttime light intensity, population density, and facility density. The UBUE at national and urban scales was assessed for 35 Chinese cities. Three significant findings emerge. First, UBUE shows significant spatial variation at national and urban scales, with a maximum disparity of 4.3 times among the 35 cities and a gradual decline along the urban–rural gradient within urban areas. Second, in cities in the western and northeastern areas, a smaller amount of urban function was generated per unit of newly constructed building volume, indicating that newly increased buildings are less efficient. Third, the scaling exponents of most cities were less than one, suggesting a marginal diminishing effect in the relationship between urban function and building volume. The marginal diminishing effect was more pronounced in economically developed cities. The comprehensive investigation of the relationship between urban function and building volume provides a scientific basis for land development allocation policies and urban growth regulation.