A green roof is a building rooftop partially or entirely covered with vegetation and additional layers of supplementary materials. Green roofs typically comprise vegetation, fabric filters, drainage elements, root barriers, insulation, and waterproofing layers. Green roofs are classified into intensive and extensive categories. Extensive roofs, in contrast to intensive roofs, feature a shallow base, necessitating no additional structural reinforcement, demand minimal maintenance, and are less costly. Green roofs yield environmental, social, and economic benefits such as reducing stormwater runoff, providing thermal insulation, delivering psychological advantages, enhancing air quality, prolonging roof lifespan, augmenting urban food productivity, and preserving urban biodiversity

Source:

WanTing Wang, Hongxing Yang, ChangYing Xiang, Green roofs and facades with an integrated photovoltaic system for zero energy eco-friendly building – A review, Sustainable Energy Technologies and Assessments, Volume 60, 2023, 103426, ISSN 2213-1388. https://doi.org/10.1016/j.seta.2023.103426