The impact of urban vegetation morphology on urban building energy consumption during summer and winter seasons in Nanjing, China

• Typical urban building-vegetation morphological prototypes are extracted. • A co-simulation technique combining urban microclimate and urban energy is proposed. • A quantitative analysis of the correlation between urban energy use and urban vegetation morphology is presented. • Key morphological parameters of vegetation affecting urban energy are determined. Studies have shown that urban vegetation can be an effective strategy for reducing energy consumption in urban buildings by regulating the microclimate and shading solar radiation on building surfaces. However, an understanding of the potential energy savings of vegetation morphological planning at the urban scale is still lacking, particularly regarding the quantitative correlation between urban vegetation morphology and its impact on urban building energy use. The morphology of the metropolitan area in Nanjing, a typical hot summer/cold winter city in eastern China, was statistically analyzed, and 40 urban building-vegetation morphological prototypes were extracted. Using the proposed co-simulation technique for urban microclimate and urban building energy, the summer and winter building energy consumption of the prototypes were simulated. A quantitative analysis was conducted on the relationship between urban vegetation morphology indexes and building energy consumption. The results indicate that strategically planned urban vegetation morphology can significantly reduce urban building energy consumption. In the summer, vegetation close to the geometric center of the site, uniformly distributed and highly mixed with buildings, can significantly reduce the building energy consumption; in the winter, the opposite is true. The presented findings provide designers and planners with strategies for incorporating urban vegetation morphology design into the construction of energy efficient cities.