Evaluating buildings and urban external layout green retrofitting to improve micro-climate conditions at district level

In the context of sustainable cities and communities, to meet the European aim of a carbon-free economy by 2050 and to tackle current climate change, the retrofitting of Italian residential building stock as well as the green regeneration of urban districts is essential. The research aims at assessing the influence of some cooling strategies applied in a defined hypothetic but realistic urban grid located in 3 different Italian cities (Milan, Florence and Palermo) evaluating multistorey, tower and courtyard building types respectively. Using ENVI-met software several micro-climate parameters are evaluated. The most significant outcomes are related to the substitution of the current dark asphalt (reference case) with cool pavements as cool improvement strategy. This measure results in a reduction of external air temperature (~ 1.2°C). Additionally, the application of green facade technology on buildings noticeably impacts both the wall surface temperature (Milan,Florence and Palermo: reduction of around 10°C–12°C) and the wall energy balance with respect to traditional external wall configurations. For the city of Palermo the cool redevelopment measures results in a slight improvement in terms of microclimate parameters compared to other cities.