Public and Private Economic Feasibility of Green Areas as a Passive Energy Measure: A Case Study in the Mediterranean City of Trapani in Southern Italy

Green infrastructure in urban environments provides a wide range of ecological, social, aesthetic, and health co-benefits. Urban plant covers in particular contribute to improved outdoor environmental conditions that, in turn, influence the energy behavior of buildings and their indoor thermo-hygrometric comfort performance. Within this context, this study illustrates a methodology aimed at verifying the economic feasibility of alternative types of green areas for public and private stakeholders, which are analyzed as passive energy measures. Therefore, our methodology integrates approaches from different disciplines and consists of a microclimatic analysis of different vegetation scenarios and of the outdoor comfort level, an evaluation of the energy needs of a sample of houses, and an economic feasibility estimation considering different scenarios and public and private investors. The methodology is illustrated through its application to a suburban district of the Sicilian city of Trapani in the South of Italy, considered representative of Mediterranean climate conditions. Results showed significant differences between the scenario outcomes depending on the type of vegetation used in the green areas and put in evidence how economic feasibility for some stakeholders may be achieved in the management phase if adequate incentives equal to the planting cost are assumed.