Biodiversity assessment of green roofs for green building design

Abstract

Green roofs can provide several environmental benefits in urban cities and can also create habitat for living organisms thus help to enhance biodiversity. At present, many green building assessment methods have considered green roofs as a desirable sustainable design feature, however, the approach to assess the biodiversity aspect in these methods is not clear and effective. This research aims to investigate how green roofs can enhance biodiversity in an urban environment and to develop an effective system to assess the green roofs. Firstly, the basic concepts and significance of biodiversity conservation were studied. Secondly, the important factors and considerations for using biodiversity as a criterion for assessing green roofs were evaluated. Thirdly, a systematic method to assess the biodiversity effects was established. Finally, the design strategies to maximise urban biodiversity of green roofs were discussed. It is found that building development in the urban areas will destroy the habitats and result in biodiversity loss; the built environment created by green roofs is one of the mitigation methods for biodiversity conservation. Some urban cities in Europe and North America are developing research studies and government policies on biodiversity and green roofs. After reviewing the existing green roof guidelines and green building assessment methods, useful information was obtained to develop a systematic method for assessing the biodiversity effects. The method comprises of six major factors: (a) species diversity and richness, (b) substrate type and depth, (c) plant species selection, (d) connectivity to natural environment, (e) green roof ratio and (f) ecologically responsible development.