## 3 Results
### Results at the Building Level
#### 3.2.2 Energy Analysis  
In order to identify the most appropriate wall retrofitting solution, depending on the location, the analysis needs to be extended to the energy demand. This analysis was carried out by first estimating the heating need (Qh) and the cooling need (Qc) separately for the different solutions, and then assessing the global energy demand. The energy demands for Monfero (a) and Turin (b) are summarized for the different retrofitting configurations in Figure 10. Analyzing the results of Turin, it can be observed that the walls without any retrofitting interventions have shown a very high heating demand of 157.45 kWh/m\({}^{2}\). The configuration that adopts the counter wall in general has a lower heating demand than the configuration based on thermal plasters. The best solution of all the counter walls is the one with VIP C2 (69 kWh/m\({}^{2}\)). The thermal plasters result in a higher demand, ranging from 87 to 120 kWh/m\({}^{2}\). The most performant is the thermal plaster with aerogel (P5), with 87.65 kWh/m\({}^{2}\), while the least is the thermal plaster with PCMs (P6), which reaches 122.33 kWh/m\({}^{2}\). When the energy demand obtained for Monfero is analyzed, the results are lower than in Turin, due to the warmer winter climate. However, the trend of the different solutions is the same. The wall without insulation achieves 96.25 kWh/m\({}^{2}\), the counter wall with VIP (C2) achieves 27.13 kWh/m\({}^{2}\) and the best solution of all the thermal plasters is the one with aerogel (P5), with a heating demand of 43.82 kWh/m\({}^{2}\). When considering the results for Monfero obtained in the summer season, the wall without any intervention certainly works better than the other solutions due to the high thermal inertia. Interesting results are obtained for the thermal plasters, which show the cooling energy demand at nearly zero. Solution P6 (thermal plaster mixed with PCMs) shows the lowest cooling demand (\(\sim\)1 kWh/m\({}^{2}\)), but solution P3 (thermal plaster mixed with cork) also shows a very low cooling demand (\(\sim\)1.4 kWh/m\({}^{2}\)). The configurations based on the counter wall always show a higher cooling demand than the thermal plasters. Nevertheless, the difference in the cooling demand (Qc) between plasters and counter walls is negligible in the Turin climate.  
Figure 9: Cumulative hours per year for certain thermal comfort categories (PMV): 0.8 met, metabolic activity in Monfero (**a**) and Turin (**b**); 1 met in Monfero (**c**) and Turin (**d**); 1.2 met in Monfero (**e**) and Turin (**f**).  
As a result of space and integration problems, the installation of a cooling system in a historical building represents a relevant issue that has to be evaluated carefully. In some cases, designers might avoid HVAC installations as they can compromise the aesthetics and morphology of a building. The results for Monfero show that counter walls have a slightly lower global energy demand (Qh + Qc) than thermal plasters, but it is also clear that the energy demand for cooling is nearly zero when thermal plaster is used. This result opens the way to the possibility of avoiding the need to resort to the installation of cooling systems. The situation is quite different for Turin, since a cooling system is necessary, and it therefore appears preferable to intervene with counter walls and the solution based on mineral wool + VIP in particular, as it allows greater savings to be obtained in the winter season.