## 3 Discussion on Results
### Results on Global Costs of Measures and Primary Energy Consumption
The fact that the global cost of specific sets of measures is higher than that in the initial state entails that the starting investment is not amortised in 30 years. These sets of measures could be implemented together with an enhancement of building's facilities, namely, by taking measures to be implemented in thermal installations. In this way, global costs would be minimised through a reduction in energy consumption due to improvement in system performance. The annual savings generated after implementing sets of measures concerning energy renovation in each building can be expressed from the viewpoint of emission reduction (Table 6), and the subsequent economic saving after minimizing annual energy consumption per year (Table 7). Table 8 shows the reduction percentage in energy consumption and recovery period of initial amortisation for sets of improvement measures with lower 30-year global cost and a greater consumption reduction, according to building type. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Type of School Building** & **L0** & **Elements Improved** & **L1** & **L2** & **L3** \\ \hline \multirow{3}{*}{Type A} & & R & \(\xi\)840 & \(\xi\)842 & \(\xi\)836 \\  & FR & \(\xi\)818 & \(\xi\)815 & \(\xi\)802 \\  & & WR & \(\xi\)901 & \(\xi\)904 & \(\xi\)894 \\  & & WFR & \(\xi\)875 & \(\xi\)868 & \(\xi\)848 \\ \hline \multirow{3}{*}{Type B} & & \(\xi\)871 & \(\xi\)858 & \(\xi\)849 \\  & & FR & \(\xi\)879 & \(\xi\)866 & \(\xi\)859 \\  & & WF & \(\xi\)1047 & \(\xi\)1012 & \(\xi\)990 \\  & & WFR & \(\xi\)1047 & \(\xi\)1012 & \(\xi\)986 \\ \hline \multirow{3}{*}{Type C} & & F & \(\xi\)559 & \(\xi\)533 & \(\xi\)547 \\  & & FR & \(\xi\)578 & \(\xi\)570 & \(\xi\)568 \\ \cline{1-1}  & & WF & \(\xi\)646 & \(\xi\)622 & \(\xi\)611 \\ \cline{1-1}  & & WFR & \(\xi\)661 & \(\xi\)639 & \(\xi\)631 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: 30-year global cost of initial state L0 per m\({}^{2}\), according to type of school building, and global cost of sets of measures per m\({}^{2}\), including those with better energy performance. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Type of School Building** & **Elements Improved** & **L1** & **L2** & **L3** \\ \hline \multirow{4}{*}{Type A} & R & 10,766.4 & 10,766.4 & 11,080.8 \\  & FR & 12,338.2 & 12,573.9 & 13,281.2 \\  & WR & 13,517.0 & 13,595.6 & 14,145.7 \\  & WFR & 15,245.9 & 15,796.0 & 16,739.0 \\ \hline \multirow{4}{*}{Type B} & F & 4413.5 & 4781.3 & 5149.1 \\  & FR & 4623.7 & 4938.9 & 5306.7 \\  & WFR & 6410.1 & 7513.5 & 8249.1 \\  & WFR & 6830.5 & 7933.8 & 8827.1 \\ \hline \multirow{4}{*}{Type C} & F & 17,740.1 & 19,135.4 & 20,132.0 \\  & FR & 19,534.0 & 20,730.0 & 21,726.6 \\ \cline{1-1}  & WF & 28,503.8 & 32,291.0 & 34,483.6 \\ \cline{1-1}  & WFR & 31,095.0 & 34,682.9 & 36,875.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Emission reduction compared to the initial state per year, according to type of school building and sets of measures. Expressed in \(\text{{KgCO}}_{2}\) per year and according to building. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Type of School Building** & **Elements Improved** & **L1** & **L2** & **L3** \\ \hline \multirow{4}{*}{Type A} & R & 68686.81 & 68686.81 & 67078.37 \\  & FR & 67858.39 & 67991.44 & 68458.78 \\  & WR & 68630.09 & 68693.29 & 69022.59 \\  & WFR & 69732.76 & 610,057.07 & 610,684.08 \\ \hline \multirow{4}{*}{Type B} & F & 62799.90 & 63032.30 & 63284.72 \\  & FR & 62936.67 & 63153.51 & 63399.25 \\  & WF & 64080.88 & 64784.74 & 65266.22 \\  & WFR & 64343.30 & 65053.84 & 65624.27 \\ \hline \multirow{4}{*}{Type C} & F & 68297.11 & 68954.29 & 69410.83 \\  & FR & 69133.15 & 69741.87 & 610,192.79 \\ \cline{1-1}  & WF & 613,510.74 & 615,446.24 & 616,439.34 \\ \cline{1-1}  & WFR & 614,599.98 & 616,362.83 & 617,343.28 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Average annual saving according to type of school building due to reduction in energy consumption, according to sets of measures.