## 3 Results and Discussion  
### Energy Saving Measures  
The theme of system adaptation represents one of the most delicate issues connected to architectural restoration. In particular, this type of intervention must take into account \begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{3}{c}{**Thermal Requirement of the Building**} \\ \hline Total primary energy requirement & 764,581.71 & kWh \\ Thermal energy requirement for heating & 177,852.80 & kWh \\ Cooling thermal energy requirement & 68,202.45 & kWh \\ Domestic hot water thermal energy requirement & 732.38 & kWh \\ Electricity requirement for lighting & 38,315,00 & kWh \\ Design thermal load & 151,664.00 & kW \\ CO\({}_{2}\) emissions & 331,216.79 & kg/year \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Thermal requirement of Ex Zoological Institute. Figure 7: BIM model of the building under study. the new needs to be met in order to guarantee standards of well-being and functionality dictated by the vocation attributed to the historic buildings. The intervention program must be adequately calibrated to the needs of the historic building, limiting the interference on the pre-existing structure in compliance with the historical value, and assessing the compatibility of the intervention to be made. It is therefore important to underline how it is possible to significantly reduce energy consumption through interventions that make the building envelope and the use of systems efficient. Evidently, it is important that users are properly oriented toward energy saving practices. The new plant equipment must therefore interact positively with the building, correcting the harmful environmental conditions in order not to damage the building, and guaranteeing comfort inside. Furthermore, the interventions will have to guarantee savings in terms of CO2 emissions as well as money. The calculation of CO2 emissions was carried out with the support of data from the ISPRA database, reporting the predefined emission factors and calculating the electricity 1 kWh produces 0.4332 kg of CO2 [32]. Following the direct and indirect analysis performed on the building, also supported by in-depth historical research, it was possible to identify the areas of intervention on which to act. The interventions concern passive technologies, such as the building envelope and active technologies such as systems. As far as the envelope is concerned, the hypothesis of intervening on the perimeter wall by using thermal coats was excluded to safeguard the historical heritage of the building. However, this approach could be adopted only on the rear elevation of the building with a thermal plaster. As far as the transparent locking systems are concerned, it was decided to keep the historic fixtures, replacing the aluminum ones with wooden fixtures as they were designed before. The replacement of all the glasses with a double glazing loaded with Argon in the cavity to ensure adequate thermal and acoustic insulation is foreseen. Furthermore, it is expected that the wooden or PVC shutters will be maintained or added where they are not present. The use of high-performance windows makes it possible to minimize the heat gain in the warmer months and to avoid heat losses in the colder months. From the analysis of the building, no installations of historical-artistic value to be protected were identified. SPLIT-type heating and cooling systems were detected in the individual rooms of the building, with an external machine in correspondence with the elevations, and a single centralized system in correspondence with the Zoology Museum. It was deemed appropriate to provide for the removal of all SPLIT-type systems and, consequently, of the external machines present on the elevations of the building. We propose the construction of a centralized system with a 150 kW heat pump serving the entire building for winter and summer air conditioning equipped with air ducts inside the false ceiling. Whereby necessity the system remains visible, attention is paid to its design.