# Energy Renovation of Residential Buildings in Hot and
## 3 Results and Discussion  
A total of 576 energy renovation solutions were proposed, given that there are 12 combined climate zones, four systems, four types of insulation, and three optimization criteria. To name each of these solutions, the nomenclature CZ-JCZ-Sx-Insu-OC is used, where CZ refers to the climate zone, JCZ refers to the January climate zone, Sx refers to the system used (S1, S2, S3 or S4), Insu refers to the thermal insulation material (EPS, MW, PUR, or XPS) and OC refers to the optimization criteria (H for heating, C for cooling, or HC for heating and cooling). Applying the methodology developed in Sections 2.5 and 2.6, for each proposed energy renovation solution, the optimum insulation thicknesses were determined, and the energy parameters required to achieve NZEBs and the economic impacts were estimated. Within each combined climate zone, those solutions that comply with the NZEB requirements were selected, and in the absence of any solution, the best solution from the economic point of view was selected for each system used. Table 10 shows the 51 energy renovation solutions that would comply with the NZEB requirements. The renovated buildings that could become NZEBs include the following:  
* Those located in climate zone A3, both mainland and non-mainland, that use system 1 or 2, optimizing the insulation thickness to minimize the total heating and cooling costs; those that use system 3 and MW insulation, optimizing the insulation thickness to minimize the total heating and cooling costs; and those that use system 4 and MW or PUR insulation, optimizing the insulation thickness to minimize the total heating and cooling costs. * Those located in climate zone A4 that use system 1 or 2, optimizing the insulation thickness to minimize the total heating and cooling costs, or those that use MW insulation, optimizing the insulation thickness to minimize the total heating costs; those that use system 3, optimizing the insulation thickness to minimize the total heating and cooling costs; and those that use system 4, optimizing the insulation thickness to minimize the total heating and cooling costs, or those that use MW insulation, optimizing the insulation thickness to minimize the total heating costs. * Those located in climate zones B4, C3, and C4 that use system 1 or 2 and MW insulation, optimizing the insulation thickness to minimize the total heating and cooling costs. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline
**Climate** & \multicolumn{3}{c}{**Labels for Non-Renewable Primary Energy Consumption**} & \multicolumn{3}{c}{**Labels for CO\({}_{2}\) Emissions**} \\ \cline{2-13}
**Zone** & **A** & **B** & **C** & **D** & **E** & **F** & **A** & **B** & **C** & **D** & **E** & **F** \\ \hline A3 & 12.3 & 23.3 & 39.4 & 63.1 & 134.2 & 146.2 & 2.9 & 5.4 & 9.2 & 14.7 & 32.7 & 36.9 \\ A3 * & 13.6 & 25.7 & 43.5 & 69.7 & 146.8 & 160.0 & 3.6 & 6.9 & 11.6 & 18.6 & 40.5 & 45.8 \\ A4 & 13.7 & 25.9 & 43.8 & 70.2 & 144.6 & 157.6 & 3.2 & 6.1 & 10.3 & 16.4 & 35.2 & 38.4 \\ B3 & 15.6 & 29.6 & 50.0 & 80.1 & 173.7 & 189.4 & 3.6 & 6.8 & 11.5 & 18.5 & 41.5 & 46.9 \\ B3 * & 17.2 & 32.5 & 55.0 & 88.2 & 183.2 & 199.7 & 4.5 & 8.6 & 14.5 & 23.2 & 50.4 & 56.9 \\ B4 & 19.2 & 33.1 & 54.0 & 84.8 & 184.3 & 200.9 & 4.4 & 7.7 & 12.5 & 19.7 & 44.1 & 48.1 \\ C1 & 24.2 & 39.2 & 60.7 & 93.4 & 200.0 & 226.0 & 5.4 & 8.8 & 13.7 & 21.0 & 45.9 & 55.0 \\ C2 & 26.8 & 43.4 & 67.3 & 103.5 & 212.9 & 240.5 & 6.1 & 9.9 & 15.3 & 23.5 & 49.0 & 57.3 \\ C3 & 24.5 & 42.3 & 69.1 & 108.5 & 226.7 & 247.1 & 5.6 & 9.7 & 15.8 & 24.7 & 52.4 & 59.2 \\ C4 & 26.2 & 45.2 & 73.7 & 115.8 & 237.0 & 267.8 & 6.0 & 10.4 & 16.9 & 26.5 & 54.9 & 62.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Upper limit values for the non-renewable primary energy consumption, in kWh/m2-year, and CO2 emissions, in kg CO2/m2-year, labels for multi-family buildings in each climate zone [56]. (*) Non-mainland climate zone.