*3.4. Overall Results*

As described in Table 7, the certification process in the case study could achieve 47 points toward LEED O+M certification, corresponding to a Certified level (40–49 points). This is a good result because the application of the methodology guarantees the certification only by the calculation of 10 credits, but above all, confirms a good level of sustainability focusing on the management of energy use and the improvement of indoor quality. The same procedure could be applied and verified for other LEED rating systems given the identical structure, but also to other certification systems based on criteria, indicators, ratings, and the certification process.

With the adoption of a LEED protocol, a single intervention measure could result in the achievement of different credits. For example, the intervention for the same inefficiencies, analyzed by energy diagnosis, could be evaluated by environmental impact; the improvement involves the selection and calculation of credits that concern n these items and inefficiencies (Table 8). A higher the score evaluated based on available credits, the higher the assessment of the environmental improvement achieved.


**Table 8.** Description of the analyzed inefficiencies. Each intervention is defined using a qualitative assessment according to the energy improvement, sustained costs, economic benefits, and preservation of the historical asset (+ positive value, - negative value).

In the description each credit, the rating system considers a list of related credits that are similar or comparable in terms of items or calculation approach. Table 8 shows how to address the inefficiencies and the calculation of the requirements for a list of credits. For example, in the Ca' Rezzonico analysis, a Base level of certification should be achieved by the application of recommended credits, but the calculation of related credits, as proposed in Table 9, could increase the level.


**Table 9.** Environmental assessment of the interventions examined using energy diagnosis. The recommended measures are selected according to the credits in LEED O+M, specifying the nomenclature of the reference credit and the related credits. The last column reports a qualitative environmental assessment.
