## 4 Results and Discussion
### Life Cycle Assessment
In particular, the LCA evaluation is highly sensitive to the assumptions regarding photovoltaic productivity, which in turn depends on the environmental conditions. In this research, the actual conditions of the surroundings of the case study were considered, which is located in a warm temperate climate area (Cfa), according to the Koppen classification, corresponding to climate zone E as defined by Italian regulations [62]. However, changes in the climatic zone could significantly affect the photovoltaic productivity. Within the Italian context, for instance, productivity could decrease by approximately 30% in alpine regions and increase by about 25% in Sicily, compared to the values estimated for the case study [60]. In addition, variations in the climatic zone would also have a significant impact on the building loads, which could either increase or decrease depending on the external climatic conditions. Moreover, factors such as the roof slope, its orientation with respect to north, and the presence of shading would considerably influence the system's productivity. In this study, two roof pitches inclined at 35\({}^{\circ}\) and oriented towards east and west, respectively, were \begin{table}
\begin{tabular}{l c c c c c c c c} \hline \multicolumn{2}{l}{External Wall} & & & & & & & & \\ \hline \multicolumn{2}{l}{External Wall} & & & & & & & & \\ \hline \multirow{6}{*}{Cra.} & ID & Layer & Th. & Th. Cn. & Th. Rs. & Mass & SH.Cp. & Vp. Rs. \\  & & 1 & Steel plate & [mm] & [W/m K] & [m\({}^{2}\) K/W] & [kg/m\({}^{3}\)] & [kJ/kgK] & [-] \\  & & 2 & EPS foam board & 120.00 & 0.0310 & 3.871 & 15 & 1.45 & 60 \\  & 3 & Steel plate & 0.50 & 52.0000 & 0.000 & 7800 & 0.45 & 9,999,999 \\  & & U-value & & Tot. Th. & S.Mass & Vice & f & \(\Delta\tau\) & \\  & & & [W/m\({}^{2}\) K] & [mm] & [kg/m\({}^{2}\) K] & [-] & [h] & [10\({}^{-12}\) kg/sm\({}^{2}\)Pa] \\  & & & 0.246 & 121 & 10.0 & 0.245 & 0.996 & \(-\)0.6 & 0.020 \\ \hline \multicolumn{2}{l}{Roof} & & & & & & & & \\ \hline \hline \multirow{6}{*}{Cra.} & ID & Layer & Th. & Th. Cn. & Th. Rs. & Mass & SH.Cp. & Vp. Rs. \\  & & ID & Layer & [mm] & [W/m K] & [m\({}^{2}\) K/W] & [kg/m\({}^{3}\)] & [kJ/kgK] & [-] \\  & & 1 & PVC cladding & 20.00 & 0.1700 & 0.118 & 190 & 0.90 & 50,000 \\  & & 2 & Vertilated cavity & 20.00 & 0.1250 & 0.160 & - & - & - \\  & 3 & Steel plate & 0.50 & 52.0000 & 0.000 & 7800 & 0.45 & 9,999,999 \\  & 4 & EPS foam board & 120.00 & 0.0310 & 3.871 & 15 & 1.45 & 60 \\  & 5 & Steel plate & 0.50 & 52.0000 & 0.000 & 7800 & 0.45 & 9,999,999 \\  & & U-value & Tot. Th. & S.Mass & Vice & f & \(\Delta\tau\) & W \\  & & [W/m\({}^{2}\) K] & [mm] & [kg/m\({}^{2}\)] & [W/m\({}^{2}\) K] & [-] & [h] & [10\({}^{-12}\) kg/sm\({}^{2}\)Pa] \\  & & 0.232 & 161 & 37.0 & 0.226 & 0.973 & \(-\)1.6 & 0.018 \\ \hline \multicolumn{2}{l}{Ground Floor Slab} & & & & & & & \\ \hline \hline \multirow{6}{*}{Cra.} & ID & Layer & Th. & Th. Cn. & Th. Rs. & Mass & SH.Cp. & Vp. Rs. \\  & 1 & Perforated raised floor & [mm] & [W/m K] & [m\({}^{2}\) K/W] & [kg/m\({}^{2}\)] & [kJ/kgK] & [-] \\  & 2 & Vertilated cavity & 20 & 52.0000 & - & 7800 & 0.45 & - \\  & 3 & Concrete scored & 300.000 & - & - & - & - & - \\  & 4 & Waterproofing membrane & 60 & 0.1700 & - & 1000 & 1.00 & - \\  & 5 & Reinforced concrete slab & 200.00 & 2.5000 & - & 2400 & 1.00 & - \\  & 6 & Coarse gravel & 300.00 & 0.7000 & - & 1500 & 1.00 & - \\  & 1 & U-value & Tot. Th. & S.Mass & Vice & f & \(\Delta\tau\) & W \\  & & [W/m\({}^{2}\) K] & [mm] & [kg/m\({}^{2}\)] & [W/m\({}^{2}\) K] & [-] & [h] & [10\({}^{-12}\) kg/sm\({}^{2}\)Pa] \\  & & 0.886 & 887 & 1020.0 & 0.025 & 0.028 & \(-\)17.9 & 0.040 \\ \hline \end{tabular}
\end{table} 
Table 5: Stratigraphy of main elements of the building envelope, where Th. : thickness; Th. Cn. : thermal conductivity; Th. Rs. : thermal resistance; Ms.: mass; SH.Cp. : specific heat capacity; Vp. Rs. : vapor resistance; U-value: thermal transmittance; Tot. Th.