**2. Materials and Methods**

The specific issues connected with the analyses of historic buildings in the framework of sustainable and green retrofit must be considered. For creating a procedure to lead environmental retrofitting, the examination and deconstruction of different approaches available in standards and legislations are necessary. Here is considered the general scheme of the process of energy diagnosis defined in the UNI CEI EN 16247-1:2012 standard [26] and the green energy audit referring to the UNI EN 16883:2017 standard [36]. It is also considered the LEED O+M rating system that focuses on management and operative aspects.
