## 3 Results and Discussion
As presented in Table 4, for the base case scenario identified in the study, the total cost is calculated as 42.60 USD/m\({}^{2}\), and the total CO\({}_{2}\) emission is 20.14 kg/m\({}^{2}\) for Zone I. In the optimum cost scenario, the total cost has decreased to 34.27 USD/m\({}^{2}\), while the total CO\({}_{2}\) emission is determined to be 15.50 kg/m\({}^{2}\). In the optimum CO\({}_{2}\) scenario, although the cost has increased (52.45 USD/m\({}^{2}\)), a huge improvement is observed in the CO\({}_{2}\) amount (9.18 kg/m\({}^{2}\)). In the cost-oriented optimum scenario determined using the knee point approach, the total cost has decreased to 38.84 USD/m\({}^{2}\), and the total CO\({}_{2}\) emission to 13.68 kg/m\({}^{2}\). In the CO\({}_{2}\)-oriented optimum scenario, the total cost has been determined to be 43.56 USD/m\({}^{2}\), and the total CO\({}_{2}\) emission is 10.17 kg/m\({}^{2}\). Table 5 and Figure 8 present the optimum conditions for various objectives for Zone II. When the option with the lowest cost is selected as optimal, an EPS insulation material with a thickness of 4.99 cm should be chosen for insulation, along with brick for the wall \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Method**} & \multirow{2}{*}{**Scenario**} & \multicolumn{2}{c}{**Cr**} & \multirow{2}{*}{
\begin{tabular}{c} **M\({}_{\text{CO2}}\)** \\ **(USD/m\({}^{2}\))** \\ \end{tabular} } & \multirow{2}{*}{\% \(\mathbf{C_{T}}\)} & \multirow{2}{*}{\% \(\mathbf{M_{CO2}}\)} \\ \hline \multirow{4}{*}{CCGDE3} & Base Case Scenario & 42.60 & 20.14 & - & - \\  & Optimum Cost & 34.27 & 15.56 & 20\% & 23\% \\  & Optimum CO\({}_{2}\) & 52.44 & 9.18 & \(-\)23\% & 54\% \\  & Optimum Cost & 34.27 & 15.55 & 20\% & 23\% \\  & Optimum CO\({}_{2}\) & 52.41 & 9.18 & \(-\)23\% & 54\% \\  & Optimum Cost & 34.27 & 15.55 & 20\% & 23\% \\  & Optimum CO\({}_{2}\) & 52.45 & 9.18 & \(-\)23\% & 54\% \\  & Optimum Cost & 34.27 & 15.50 & 20\% & 23\% \\  & Optimum CO\({}_{2}\) & 52.45 & 9.18 & \(-\)23\% & 54\% \\  & Cost-Oriented Knee Point & 38.84 & 13.68 & 9\% & 32\% \\  & CO\({}_{2}\)-Oriented Knee Point & 43.56 & 10.17 & \(-\)2\% & 50\% \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Total costs, carbon emissions, and their percentage changes compared to the base case scenario for Zone I.  
Figure 7: CO\({}_{2}\) and total cost values at optimum points obtained for different objective functions (Zone I). and natural gas for heating. Conversely, when the option with the lowest emission is selected as optimal, an EPS insulation material with a thickness of 20.55 cm should be used, paired with light concrete for the wall and natural gas for heating. In the cost-oriented scenario determined by the knee point method, the optimal configuration includes an EPS insulation material with a thickness of 13.68 cm, brick for the wall, and natural gas as the heating source. In the CO\({}_{2}\)-oriented scenario identified using the same method, the optimal configuration consists of an EPS insulation material with a thickness of 8.29 cm, light concrete for the wall, and natural gas as the heating source. As shown in Table 6, for the base case scenario identified in the study, the total cost for Zone II is calculated as 48.45 USD/m\({}^{2}\), with a total CO\({}_{2}\) emission of 22.40 kg/m\({}^{2}\). In the optimum cost scenario, the total cost decreases to 34.84 USD/m\({}^{2}\), while the total CO\({}_{2}\) emission is reduced to 15.79 kg/m\({}^{2}\). In the optimum CO\({}_{2}\) scenario, although the cost has slightly increased to 53.47 USD/m\({}^{2}\), the primary improvement is in the CO\({}_{2}\) emissions, which drop to 9.31 kg/m\({}^{2}\). In the cost-oriented optimum scenario identified using the knee point method, the total cost is reduced to 39.51 USD/m\({}^{2}\), and the total CO\({}_{2}\) emission to 13.83 kg/m\({}^{2}\). In the CO\({}_{2}\)-oriented optimum scenario, the total cost is determined to be 44.16 USD/m\({}^{2}\), with a total CO\({}_{2}\) emission of 10.36 kg/m\({}^{2}\).