A comprehensive study of green roof performance from environmental perspective

Green roofs have been established for over 100 years and they have been become one of the key elements in urban area in the past few decades. Many scientific researches focus on its cooling performance, efficiency and survival rates of plants. This article provides an overview mainly from two aspects, the vegetation on the green roofs and its benefits toward the surrounding environments. Vegetation is the key element in installing green roofs. It also provides some factors in choosing suitable plants on rooftops, factors including species that are drought tolerant, solar radiation tolerant, and cooling ability of plants. In addition, green roofs play a critical role in improving the urban environment by enriching the biodiversity, delaying the storm peak to the drainage system, diminishing the runoff quantity, purifying the air pollutants as well as the runoff quality.