## 4 Conclusions  
The capability of green roofs in reducing the electric energy needs for the climatization of buildings and their environmental benefits has been extensively demonstrated in the literature. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & & **Standard Roof** & **Green Roof** \\  & & **(kWh)** & **(\% Savings)** \\ \hline Jan & **Heating** & **655.1** & **17.9 ± 1.7\%** \\  & Cooling & 0 & \\  & **Heating** & **610.6** & **12.5 ± 1.8\%** \\ Feb & Cooling & 0 & \\  & **Heating** & **409.9** & **2.2 ± 3.5\%** \\ Mar & Cooling & 0 & \\  & **Heating** & 15.9 & **43.6 ± 34.3\%** \\ Apr & Cooling & 0 & \\  & **Heating** & 4.4 & **2.1 ± 24.2\%** \\ May & Cooling & 0 & \\  & **Heating** & 0 & \\ Jun & **Coiling** & **239.6** & **50.1 ± 9.8\%** \\  & Heating & 0 & \\ Jul & **Coiling** & 534.2 & **28.7 ± 7.4\%** \\ Aug & Heating & 0 & \\  & **Coiling** & 630.0 & **24.7 ± 4.9\%** \\ Sep & Heating & 0 & \\  & **Coiling** & **323.1** & **20.4 ± 4.7\%** \\ Oct & Heating & 2.0 & 62.9 ± 6.7\% \\ Oct & Cooling & 45.9 & 33.0 ± 10.7\% \\  & Heating & 69.5 & 59.3 ± 7.0\% \\ Nov & Cooling & 0 & \\  & **Heating** & **429.8** & **26.4 ± 2.5\%** \\ Dec & Cooling & 0 & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Monitoring results of the green roofs six plots. The idea behind the presented work derived from considerations regarding the possible influence of green roofs on the indoor thermal comfort levels; that is, instead, an aspect often overlooked when estimating the performance of such building components. Therefore, the analysis methodology approach utilized (partly modelling and partly experimental) was implemented in light of such considerations. Accurate knowledge of the internal temperatures of the ceiling is indeed an important prerequisite for establishing both achievable indoor comfort conditions and the energy demand for the air conditioning of the building itself. A lowering of the indoor temperatures in summer, and a rise during winter, lead, in fact to an improvement in the comfort levels for the occupants, and consequently, a saving on the use of the HVAC system, which, in turn, translates into a reduction of polluting emissions. For this purpose, the comparison between Scenario #1 (where the monitored ceiling temperatures were used as boundary conditions) and Scenario #3 (standard roof case), and that between Scenario #2 (where the green roof configuration provided by EnergyPlus was utilized) and Scenario #3, allowed to prove how the presence of the experimental green roof on the monitored building improved the indoor comfort levels during summer by moderating the ceiling temperatures (Figures 9-11 and 13), despite some worsening during winter periods seeming to occur. Moreover, the temperature differences noticed had also a positive impact on the building energy consumption and the CO\({}_{2}\) emissions. On the other hand, by comparing Scenario #1 with Scenario #2, it was possible to highlight the possible limits of the code's ability in adequately simulating the green roof behaviour. These limits are mainly represented by the lack of flexibility that EnergyPlus allows in the setting-process of some of the green roof physical parameters and in the way in which the code takes into account the solar radiation components. Another aspect which should be better investigated, regards the PMV results (Figure 12). In fact, even though, also, in this case, a general positive effect due to the presence of the green roof can be seen, some criticalities emerged during some transition periods, for which the standard roof seems to perform slightly better than the green roof. In conclusion, the proposed analysis made it possible to highlight how it is possible to assess the impact that green roofs have specifically on the indoor comfort levels, other than on the energy consumption. Furthermore, the availability of field data put into evidence the importance of adequate simulation tools to facilitate the green roof design and assessment processes.