Scale or size? An analysis of the factors that affect building density: evidence from high-density central urban zones in Asia

Building density is an important factor affecting both urban morphology and urban habitat. Recently, “compact cities” with high density have become the main trend in urban sustainable development. Yet, how to promote effectively high-density city construction through spatial measures remains a challenge. This paper investigates the central urban zones of high-density cities in Asia. The construction scale and block size of 29 central zones in 17 international cities were quantitatively studied to compare their respective relationships with building density; other related factors were also considered (geographical features and urban nature). No direct correlation between construction scale and building density was found. However, a block’s size was strongly correlated with its building density. In general, smaller block size was associated with a higher building density. Based on the results, we conclude that simply compressing scale will not effectively improve building density. Instead, the development of a small-size block may promote high-density spatial construction, thereby, facilitating the realization of compact cities and sustainable urban development.