A sustainable urban form: The challenges of compactness from the viewpoint of energy consumption and carbon emission

The construction sector has grown to have the second-highest energy consumption in China, smaller only than the industrial sector. The objective of this paper is to explore whether compactness is sustainable city form from aspects of urban household energy use carbon emission (UHEUCE). To eliminate social influence as much as possible, we designated a standard family whose social conditions represent the entire city average. Normalized compactness index, connectivity of green space (GS) and water bodies (WB), and accessibility to GS and WB by households were selected as quantitative indicators related to urban sprawl. These indicators were quantified using remote sensing and geophysical information system methods. Urban sprawl aspects of compactness were positively correlated with UHEUCE. The other urban sprawl form indicated by GS and WB connectivity had the same positive correlations with UHEUCE. The greater the GS and WB accessibility, the less UHEUCE. This indicates that designing cities to be compact with less accessibility to GS and WB may increase household energy consumption. Substantial use of GS and WB, even if they are fragmented, will reduce carbon emission from residential energy use. This study provides useful implication toward achieving scientific landscape plans for low carbon city construction.