Design of extensive green roofs for the major school plants of Piraeus

Abstract

Despite the increase of global awareness regarding environment related issues and the development of relevant international policies; effective activities to conserve open space remain inconsistent in Mediterranean cities. Additionally as urban areas continue to expand and free space at street level becomes more and more limited there is a greater need for innovative green technologies which could contribute to the creation of sustainable urban ecosystems. Green roofs on buildings have already proved valuable for storm water management, energy conservation, microclimate mitigation, pollution remediation and biodiversity restoration, but their spreading in Mediterranean cities is still very limited. The shallow-substrate extensive type of green roofs is of great interest for massive application, which would lead to great scale positive effects in urban ecosystems. In Greece, in the framework of a relevant initiative called "Green roofs on public buildings", pilot extensive green roofs for the four major school plants of the city of Piraeus were designed. These green roofs which have a total area of about 0.6 ha are located in highly populated districts with negligible green spaces. This presentation is focusing on the decision making processes during the design and the selection of the growing medium and the planting material. The methods and the parameters of the relevant landscape, bioclimatic, hydrologic, irrigation and drainage studies are also presented. It is expected that the construction of these green roofs will improve the life quality of the school communities and more generally of the citizens of Piraeus.