Environmental Benefits

At the environmental level, Berardi et al. [71] explained that the benefits of green roofs are multiple, such as: Energy consumption reduction, UHI and air pollution mitigation, water management, sound insulation, and noise reduction, as well as ecological preservation.

In the literature, several studies investigated energy savings and environmental benefits after the use of green roofs, high-reflectance roofs [48,65,73–77], and solar technologies [55–57]. For example, increasing urban albedo can reduce summertime temperatures, resulting in better air quality and savings from reduced air-conditioning costs [78]. Akabari et al. [78] found that converting 100 m<sup>2</sup> of dark roof to white o ffsets the emission of ∼10 tons of CO2, equivalent. Moreover, 100 m<sup>2</sup> of green roof has a one-time global warming o ffset potential of 3–4 tons of CO2, equivalent [79].

From the results of this work, it emerged that, through the retrofit of the roof, using, for example, green roof, environmental benefits can be obtained, thanks to the reduction of space heating and cooling consumption and, consequently, the reduction of GHG emissions with an improvement of urban thermal conditions. In future work, more detailed analyses will be made for some buildings' blocks located in the same district using the ENVI-met software [80]. This tool, based on a holistic model, is able to simulate local climate conditions in an urban environment and to assess the e ffects of green technologies on energy savings and thermal comfort conditions.
