Dynamic impacts of vegetation growth and urban development on microclimate and building energy consumption

Urban heatwaves have emerged as a critical global challenge, exacerbating extreme weather conditions and contributing to higher building energy consumption. These challenges become particularly acute during the initial phases of urban expansion. While numerous studies have independently investigated vegetation's effects on outdoor microclimates and building energy efficiency, the dynamic interactions between vegetation growth, urban development, and heatwave mitigation remain underexplored. This research examines these evolving interrelationships through integrated analysis of outdoor microclimate parameters and indoor energy performance in the context of climate change, using the new campus of Southeast University in China as a case study. Four scenarios are developed based on different stages of tree growth and urban construction: climate change only, as plan, stop construction, add trees in plan. Both simulations and experiments are conducted to assess the impact of the dynamic changes in these scenarios. The long-term impacts of these factors on microclimate and building energy consumption are assessed by ENVI-met and EnergyPlus tools. The results indicate that after 60 years, vegetation growth can reduce the average site temperature by approximately 3 °C, expand areas of enhanced thermal comfort, and reduce total building cooling energy consumption by 15.5 %. Comparative analysis of the scenarios reveals that preserving existing trees or implementing early-stage plantation can significantly mitigate heatwave and reduce cooling energy demand. This research provides valuable insights for future urban renewal and sustainable city development, offering practical guidance for urban planners to optimize urban environments and improve energy efficiency.