1
Department of Architecture, FIA.C. Islamic Azad University, Tehran, Iran
2
Department of Architecture, Za.C., Islamic Azad University, Zanjan, Iran
10.22099/iuds.2026.56656.1239
Abstract
Rapid urbanization and vertical development in metropolitan areas have turned the urban heat island (UHI) phenomenon into a fundamental challenge affecting environmental quality and citizens' thermal comfort. Dark-colored roofs, through absorption and storage of solar energy, significantly exacerbate this phenomenon. Therefore, their modification is a key strategy in urban planning and design. This study quantitatively evaluates the cool roof strategy (high albedo and high thermal emissivity) in mitigating UHI and improving thermal homogeneity in high-rise neighborhoods of District 22, Tehran. Using ENVI-met microclimate simulation, the impact of replacing roof materials across all buildings was analyzed on key thermal comfort indices during the summer solstice. Findings indicate that cool roofs, by reducing mean radiant temperature by 5.5–10.5°C at pedestrian level and surface temperatures by 5–10°C, not only decrease UHI intensity but also improve temperature distribution homogeneity at the neighborhood scale by reducing the air temperature coefficient of variation by up to 44%. Compared to low-rise and high-rise typologies, the mid-rise typology (6–10 stories) was identified as the optimal urban fabric, offering the highest thermal stability throughout all daytime hours. The main contribution is introducing cool roofs as a passive, scalable, and cost-effective strategy for reducing microclimatic heterogeneity and enhancing environmental quality in high-rise urban fabrics. Furthermore, "thermal homogeneity" is proposed as a novel metric for evaluating UHI mitigation strategies. Its quantitative measurement provides an analytical-design tool for urban planners and designers to achieve more balanced and equitable microclimates through optimal typology selection and reflective roof materials. The findings can inform climate-sensitive urban design guidelines in high-rise contexts. However, generalizing results to other regions and seasons requires further research.
Nosrati, M. , Alavi, P. and Khatibi, A. (2026). Evaluating Cool Roofs in Climate-Sensitive Urban Design: Assessing Thermal Homogeneity in High-Rise Neighborhoods of Tehran. Iranian Urban Design Studies, (), -. doi: 10.22099/iuds.2026.56656.1239
MLA
Nosrati, M. , , Alavi, P. , and Khatibi, A. . "Evaluating Cool Roofs in Climate-Sensitive Urban Design: Assessing Thermal Homogeneity in High-Rise Neighborhoods of Tehran", Iranian Urban Design Studies, , , 2026, -. doi: 10.22099/iuds.2026.56656.1239
HARVARD
Nosrati, M., Alavi, P., Khatibi, A. (2026). 'Evaluating Cool Roofs in Climate-Sensitive Urban Design: Assessing Thermal Homogeneity in High-Rise Neighborhoods of Tehran', Iranian Urban Design Studies, (), pp. -. doi: 10.22099/iuds.2026.56656.1239
CHICAGO
M. Nosrati , P. Alavi and A. Khatibi, "Evaluating Cool Roofs in Climate-Sensitive Urban Design: Assessing Thermal Homogeneity in High-Rise Neighborhoods of Tehran," Iranian Urban Design Studies, (2026): -, doi: 10.22099/iuds.2026.56656.1239
VANCOUVER
Nosrati, M., Alavi, P., Khatibi, A. Evaluating Cool Roofs in Climate-Sensitive Urban Design: Assessing Thermal Homogeneity in High-Rise Neighborhoods of Tehran. Iranian Urban Design Studies, 2026; (): -. doi: 10.22099/iuds.2026.56656.1239
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