A comparison between environmental sustainability rating systems LEED and ITACA for residential buildings

The paper presents a comparison between two different rating systems to evaluate buildings sustainability: LEED (USA) and ITACA (Italy), thanks to the application of both methods to two residential buildings located in Italy. The LEED green building rating system encourages an integrated design approach, with a points scheme that allots credits for building design features deemed to improve sustainability, which includes reductions in energy use, improvements in indoor environment quality, protection of the construction site, reduction in water consumption and use of sustainable materials. ITACA procedure, the environmental quality rating system adopted in Italy, consists of the compilation of a group of worksheets, one for each different performance indicator, at the aim of describing the building environmental quality, including the maintenance of indoor comfort during the entire life cycle. The chosen buildings are located in central Italy; they are both energy efficient and designed according to the principles of bioclimatic architecture, even if they are characterized by different features. Five common areas (site, water, energy, materials, indoor environmental quality) were identified in order to compare the two methods and to normalize their score; this original approach can be transferred also to the comparison of other building environmental assessment tools. The comparison allows to prove the main features of both schemes. Even though the two procedures give different importance to the various areas, the analysis show a proportionality between the respective normalized final score for the two examined buildings.