Optic-energy performance of innovative and traditional materials for roof covering in commercial buildings in central Italy

Innovative and traditional solutions for roof coating and urban paving are under development in order to study their effect both as passive cooling strategies for buildings and as effective tools for urban heat island mitigation. This paper deals with the optic-energy in-lab and numerical analysis of three materials used for roof covering and urban paving in Italy. Bitumen covering, cool painting and natural gravel covering are taken into account. Solar reflectance measurements shows that gravel optimize this property by more than 20% with respect to the bitumen covering of classic streets paving. The three materials are also evaluated in terms of roof covering in commercial buildings with flat roofs. Dynamic simulation results demonstrated that innovative cool membranes are able to optimize building year-round energy efficiency by 19.3%. Nevertheless, natural gravel covering produce important energy saving (15.6%) with respect to bitumen roof membrane configuration.