Multi-objective optimization of morphology for high-rise residential cluster with the regards to energy use and microclimate

Abstract

Urban morphology significantly influences building energy consumption, solar energy potential, and outdoor thermal microclimate. This study seeks to optimize the urban morphology of high-rise residential clusters, using a framework that emphasizes energy use, outdoor thermal microclimate and incremental investment cost at a preliminary stage of design. The proposed framework is based on performance oriented parametric simulation and implements multi-objective optimization using the Grasshopper platform to assess residential cluster morphology. The study analyzed the five morphological parameters (floor area ratio (FAR), building density (BD), average floor (AF), average orientation (AO), and average aspect ratio (AAR)) to achieve the minimize of the Net Energy Intensity (NEI), Universal Thermal Climate Index (UTCI), and Incremental Investment Cost (IIC) of residential clusters. This approach aims to enhance energy efficiency and improve summer microclimate while reducing investment costs. Additionally, analyzed the correlation between morphological parameters and three key performance metrics: Energy Use Intensity (EUI) (encompassing heating, cooling, and lighting requirements), Photovoltaic Energy Generation (PVEG), and UTCI. The findings reveal that the optimal morphology of residential clusters varies significantly depending on the desired objective. When prioritizing PVEG, a morphology characterized by low height, high density, and a small aspect ratio is recommended. It is noteworthy that in this morphology, the cluster also demonstrates optimal UTCI during the summer. Conversely, if EUI is the primary objective, a configuration with higher height and aspect ratio, along with lower density, is suggested. On the other hand, balancing the requirements of these three objectives may require a moderately-spaced layout with low height, large aspect ratio, and compact front-to-back building spacing. Under these morphologies, particular attention should be given to the layout in the north–south directions. Furthermore, southward orientation is advisable. Additionally, based on analysis of Pareto solutions, a FAR of approximately 2.6 to 2.7 is recommended.