Urban morphology and energy self-sufficiency: A comparative study of residential blocks in eight global cities

As global climate change intensifies and energy resources dwindle, residential energy consumption becomes a critical challenge. While progress has been made in understanding urban morphology and climate factors in zero-energy residential block design, comprehensive cross-contextual analysis across diverse cultural, geographical, and climatic regions remains limited. This study examines residential blocks in eight cities—The Hague, Singapore, Tallinn, Berlin, Montreal, Vienna, Vantaa, and Zurich—spanning temperate oceanic, tropical rainforest, and humid continental climates. Using modeling translation tools such as Urban Modeling Interface and Rhino, alongside methods like multiple regression analysis, recursive feature elimination (RFE), and random forest algorithms, the study analyzes 12 morphological indicators from 240 districts in these eight cities. Morphological indicators serve as independent variables, while energy self-sufficiency rates are the dependent variable, with geographical and climate factors also considered. The results reveal that building height and volume are pivotal in determining energy self-sufficiency, particularly in northern cities like Tallinn and Vantaa, where optimized urban morphology can substantially enhance energy efficiency. In contrast, despite favorable photovoltaic conditions in Central European cities such as Berlin, Vienna, and Zurich, lower energy self-sufficiency rates are observed, mainly due to the constraints imposed by current urban morphology. For Singapore, optimizing the building shape coefficients and occupancy rates is essential for improving energy self-sufficiency. This study introduces a novel evaluation framework to assess and optimize the global potential of residential districts for achieving near-zero energy consumption, emphasizing the complex interplay between urban morphology and climate.