Critical review and methodological approach to evaluate the differences among international green building rating tools

Building performances play a fundamental role in the worldwide energy scenario. In the last years, many countries have developed certification procedures in order to rate the environmental sustainability of buildings, aiming at reducing energy consumptions and environmental impacts during the construction, management and operational phases of a building. This study firstly provides an overview of the different certification procedures employed in several countries all over the world, considering also which Green Building Rating System (GBRS) is only applied in its own country and which one is developed in other countries by means of proper adaptations. Five widespread and well known green building rating systems (CASBEE, Green Star, BREEAM, LEED and ITACA) are then analyzed in detail and differences and similarities among them are highlighted. To this aim, six new macro-areas (site, water, energy, comfort and safety, materials and outdoor quality) are defined and a normalization procedure is implemented, in order to provide significant information about the sustainability aspects taken into account in the different rating tools and aiming at comparing them. This comparison allows to identify the main features of the five tools and to highlight qualitative and quantitative differences. The analysis shows that the certification tools are not homogeneous from both points of view. The aim of this work is to understand which issues have more influence on the final performance rate of each system and to give to final users a deeper knowledge of the aspects included in these tools.