BIOCLIMATIC ARCHITECTURE AS A STRATEGY FOR MITIGATING THE URBAN HEAT ISLAND EFFECT

Abstract

Cities absorb, store, and re-radiate heat far more efficiently than the natural landscapes they replace. Asphalt, concrete, glass, and dark roofing materials trap solar radiation during the day and release it slowly after sunset, while the removal of vegetation eliminates the evaporative cooling that forests and open soil once provided. The cumulative result of this shift in surface properties is the urban heat island (UHI) — the well-documented tendency of built-up areas to register significantly higher temperatures than their rural surroundings. Satellite-based research by the European Commission's Joint Research Centre, comparing summer surface temperatures of urban areas with populations above 50,000 against their rural surroundings between 2003 and 2020, found that cities are often 10 to 15 degrees Celsius hotter than the countryside around them, with the most intense heat islands warming by roughly one additional degree Celsius since 2003 alone. In the United States, the Environmental Protection Agency reports that daytime urban temperatures typically run 1 to 7 degrees Fahrenheit above outlying areas, with the gap widening to 15–20 degrees Fahrenheit in the most densely built districts on calm, clear afternoons, and nighttime differences of 2–5 degrees Fahrenheit.