Green Infrastructure and Private Property: The Crucial Relationship for the Sustainable Future of Cities

Over the past decades, intense urbanization processes have generated built environments with a low energy efficiency and a severe lack of green spaces. These represent the main providers of ecosystem services in cities, especially for the regulation of local microclimate. Despite their importance, the implementation of a green infrastructure from public administrations often faces the lack of economic resources to acquire and manage the land to be used as new green spaces. This article investigates the suitability of open spaces located in private residential areas to be components of a green infrastructure through a trees planting strategy. A high-res GIS Land Cover analysis models the potential of private residential areas to host new greenery by comparing the actual availability of open spaces near residential buildings and the mutual position between buildings and new trees. The method is tested in a portion of the Metropolitan Area of Catania (Italy). Results for private residential areas, which represents a relevant percentage of the built environment, show that the implementation of the Green Infrastructure depends on the configurations of buildings and open spaces, and is limited by the actual room of open space around residential buildings. The work allows identifying different scenarios and alternatives for a Green Infrastructure to better balance public and private costs and generated benefits.