Microclimate Response to Updated Urban Building Regulations: An Urban Evaluation Approach

Urban microclimates play a pivotal role in shaping the livability, resilience, and sustainability of rapidly urbanizing cities, particularly those exposed to coastal pressures and high population densities. In Alexandria, Egypt, where intense urbanization coincides with high humidity, the interaction between building form and local climate is increasingly critical. Historically, planning frameworks prioritized land optimization and expansion while overlooking microclimatic implications, yet climate challenges are now urging a transition toward climate-responsive approaches. This study investigates the influence of modifications in building codes specifically building height, plot coverage, and setback regulations on urban microclimatic conditions. Employing ENVI-met v5.7.2, a high-resolution simulation tool, the research analyzed four urban typologies: High-Density Type (El-Mergany Palace, Corniche), Strip Type (El-Naby Daniel Street), Courtyard Type (opposite Casino El-Shatby), and Dot Type (Masaaken El-Zobbat). Key parameters examined included air temperature, relative humidity, wind flow, and thermal comfort indicators such as PMV and Tmrt. Results reveal substantial variation among typologies, with the Courtyard Type demonstrating superior ventilation and lower peak temperatures, while High-Density forms intensified heat retention and restricted airflow. These findings underscore the role of regulatory form in shaping thermal comfort and highlight the potential of microclimate-sensitive planning to advance sustainable, climate-adaptive development in coastal MENA cities.