# A Case Study on Integrating an Eco-Design Tool into the Construction Decision-Making Process
## 3 Results and Discussion
### Case Study: Comparison of Window Frame Solutions
\begin{table}
\begin{tabular}{l c c c} \hline \hline
**Parameters** & \multicolumn{3}{c}{**Case: Window Frame Material**} \\ \hline Code & A11 & A22 & A33 \\ Material/solution & PVC & Aluminium & Wood \\ GWP (kg CO\({}_{2}\) equiv.) & 0.86 & 1.00 & 0.87 \\ ODP (kg CFC 11 equiv.) & 0.35 & 0.84 & 1.00 \\ AP (kg SO\({}_{2}\) equiv.) & 1.00 & 0.72 & 0.76 \\ EP (kg (PO\({}_{4}\))\({}^{3-}\) equiv.) & 0.44 & 1.00 & 0.67 \\ POCP (kg C\({}_{2}\)H\({}_{4}\) equiv.) & 0.63 & 1.00 & 0.65 \\ ADPE (kg Sb equiv.) & 1.00 & 0.57 & 0.58 \\ ADPF (MJ, N.C.V.) & 1.00 & 0.96 & 0.71 \\ \hline \hline \end{tabular}
\begin{tabular}{l c c} \hline \hline
**Parameters** & \multicolumn{3}{c}{**Case: Window Frame Material**} \\ \hline Code & A11 & A22 & A33 \\ Material/solution & PVC & Aluminium & Wood \\ TRR (MJ, N.C.V.) & 5.17 \(\times\) 10\({}^{1}\) & 6.03 \(\times\) 10\({}^{1}\) & 5.27 \(\times\) 10\({}^{1}\) \\ TRNR (MJ, N.C.V.) & 2.35 \(\times\) 10\({}^{-6}\) & 5.57 \(\times\) 10\({}^{-6}\) & 6.62 \(\times\) 10\({}^{-6}\) \\ MS (kg) & 2.65 \(\times\) 10\({}^{-1}\) & 1.91 \(\times\) 10\({}^{-1}\) & 2.03 \(\times\) 10\({}^{-1}\) \\ CSR (MJ, N.C.V.) & 4.70 \(\times\) 10\({}^{-2}\) & 1.07 \(\times\) 10\({}^{-1}\) & 7.11 \(\times\) 10\({}^{-2}\) \\ CSNR (MJ, N.C.V.) & 1.34 \(\times\) 10\({}^{-2}\) & 2.14 \(\times\) 10\({}^{-2}\) & 1.40 \(\times\) 10\({}^{-2}\) \\ Use of net freshwater (m\({}^{3}\)) & 2.24 \(\times\) 10\({}^{-3}\) & 1.28 \(\times\) 10\({}^{-3}\) & 1.31 \(\times\) 10\({}^{-3}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Environmental impacts after normalization of different window frame solutions. Figure 2: Normalized environmental impact of different window frame materials. impacts while, by choosing between PVC and wood window frames, one can obtain lower impacts. Table 5 shows the resource consumption normalized results as explained above in Section 2.1.2, as well as the consumption values of non-renewable and renewable materials, both shown in Figure 3. Aluminium window frames have shown the highest consumption of non-renewable resources (Figure 3a), in line with the environmental impact analysis. The normalized area was found to be 1.03 m\({}^{2}\), whereas significantly smaller areas were found for PVC and wood frames: 0.33 m\({}^{2}\) and 0.27 m\({}^{2}\), respectively. However, the consumption of renewable resources was naturally superior in wood frames (0.49 m\({}^{2}\)), surpassing the resource consumption of both PVC (0.06 m\({}^{2}\)) and aluminum frames (0.15 m\({}^{2}\)). Despite the rather similar global environmental impacts of PVC and wood window frames, wooden frames are deemed preferable due to the primarily renewable nature of the resources consumed. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Parameters** & \multicolumn{3}{c}{**Case: Window Frame Material**} \\ \hline Code & A11 & A22 & A33 \\ Material/solution & PVC & Aluminium & Wood \\ TRR (MJ, N.C.V.) & 0.34 & 0.16 & 1.00 \\ TRNR (MJ, N.C.V.) & 0.86 & 1.00 & 0.63 \\ MS (kg) & 1.00 & 0.86 & 0.07 \\ CSR (MJ, N.C.V.) & 0.00 & 0.00 & 1.00 \\ CSNR (MJ, N.C.V.) & 1.00 & 0.00 & 0.00 \\ Use of net freshwater (m\({}^{3}\)) & 0.82 & 0.76 & 1.00 \\ \hline \hline \end{tabular}  
* TRR—total use of renewable primary energy resources; TRNR—total use of non-renewable primary energy resources; MS—use of secondary material; CSR—use of secondary renewable fuels; CSNR—use of non-renewable secondary fuels; N.C.V.—net calorific value.  
\end{table} 
Table 5: Resource consumption after normalization of different window frame solutions. Figure 3: Normalized resource consumption of different window frame materials’ (**a**) consumption of non-renewable resources and (**b**) consumption of renewable resources. The eco-design tool was also embedded with a complementary board featuring the best-performing solution by parameter to provide users with a quick and easy method of evaluating specific parameters during the decision-making process. Table 6 summarizes the performance of the different window frame solutions assessed by impact category.