Green roof design: State of the art on technology and materials

In order to consider green roofs as an environmentally friendly technology, the selectionof efficient and sustainable components is extremely important. Previous review papers havemainly focused on the performance and advantages of green roofs. The objective of this paper is toexamine the primary layers: The waterproof and anti-root membranes; the protection, filter, anddrainage layers; the substrate; and the vegetation. First, the history, modern applications, benefitsand classification are analyzed in order to present a well-defined state of the art of this technology.Then, the roles, requirements, characteristics, and materials are assessed for each green roof layers.This technology was compared to a conventional roof technology, Mediterranean climateconditions and their influence on green roof design were assessed, also comparing them withTropical area and focusing on irrigation systems, examples about the commercial materials andproducts available in the market were provided and innovative materials coming from recycledsources were analyzed. Future research should evaluate new materials for green roof technologies,in order to enhance their performance and increase their sustainability. The information providedin this review paper will be useful to develop Mediterranean green roof guidelines for selectingsuitable components and materials during the design and installation phases.