Green Roof: A Holistic Approach for Ecologically Sustainable Cities

Abstract

Sustainable technologies and green design practices all over the world have a vital role on architectural practices by reducing building impacts on human health and the environment and contribute positively to the ecosystem. Factors call for improved environmental design are population growth, which increases the built up area in cities and reduce the green open spaces, high percentage of air and water pollution due to industrialization, global warming, loss of habitat and biodiversity, and increasing urban heat island (UHI). Consequently, a new approach is needed to alleviate these problems; one of these approaches is green roofs which recognized as an effective sustainable design tool that soften the harsh urban environment. Green roofs or the so called 'fifth facade' have had diverse environmental benefits such as improving the surrounding environment, insulation properties, purifying the air pollutants through the foliage which absorb dust particles, carbon dioxide, and other pollutants, building energy saving, it also presents the correlation between a green rooftop and improving micro-climate for both individual buildings and neighborhood. In addition, green rooftops provide a visual interesting layer with plenty texture and color instead of uncovered roof. Generally, the results verified that green-roof enhance building microclimate, conserve energy, increase occupants' comfort and health, and compensates for the green-space deficit in cities.