On the impact of urban climate and heat islands on building energy performance: A critical review

Abstract

Urban Heat Islands (UHIs) substantially alter local climates, yet their impacts on building energy performance remain inconsistently quantified and poorly integrated into simulation workflows, energy codes, and planning practice. This review critically synthesizes U.S.-based studies that model the impacts of the UHI effect on building heating and cooling loads, revealing substantial variability in the reported energy impacts. Depending on climate conditions and building type, studies report cooling load increases ranging from 4% to 65% and heating load reductions from 3% to over 100%. These wide ranges stem largely from methodological inconsistencies, including divergent UHI quantification techniques, mismatched spatial scales between climate and energy models, and inconsistent integration strategies. The review highlights key gaps, including the widespread use of oversimplified rural baseline weather files, the exclusion of non-thermal microclimatic variables such as wind and humidity, over-reliance on the U.S. Department of Energy (DOE) prototype buildings, and limited representation of colder and warm-dry climate zones. Moreover, results are often difficult to compare due to inconsistent reporting metrics and a lack of reproducibility. Addressing these gaps requires standardized UHI-adjusted weather data, expanded research across all climate zones, and greater consideration of non-code-compliant buildings and socioeconomic disparities. The research advocates the need to address these issues by integrating UHI effects into Building Energy Modeling (BEM) workflows, energy codes (e.g., ASHRAE, IECC), and urban climate policies to enhance predictive accuracy and inform climate-resilient design and planning strategies.