Microclimate effects and outdoor thermal comfort of green roof types in hot and dry climates: Modelling in the historic city of Yazd, Iran

Intensive green roofs significantly enhance thermal comfort and modify microclimate parameters in Yazd, Iran's hot and arid climate, outperforming extensive green roofs and non-vegetated roofs. Simulation using the ENVI-met model revealed that intensive green roofs reduced air temperature, mean radiant temperature, and longwave radiation while increasing wind speed and relative humidity, creating more comfortable conditions (PMV = 0.18) during early morning hours (7:00–9:00 am). However, despite these improvements, all scenarios remained classified as 'very hot' or 'hot,' indicating limited effectiveness under Yazd's extreme climatic conditions, characterized by high temperatures, intense radiation, and severe water scarcity. The study suggests that while green roofs can ameliorate microclimate and thermal comfort, their practical application in such harsh environments is not advisable.

Karimian, Z., & Mahdizadeh, S. (2025). Microclimate effects and outdoor thermal comfort of green roof types in hot and dry climates: Modelling in the historic city of Yazd, Iran. PLOS One, 20(6), e0325494. https://doi.org/10.1371/journal.pone.0325494