# A Sustainability Analysis Based on the LCA-Energy-Carbon Emission Approach in the Building System
## 4 Results and Discussion
### LCA-Emergy Analysis
#### 4.1.2 Energy Indexes Analysis  
In Table 2, six primary indexes have been shown for the sustainable state. Compared with renewable input and energy feedback input, the nonrenewable resource input occupies a dominant position. Based on the Ri, N\({}_{\text{s}}\) and E\({}_{\text{f}}\), EYR and ELR have been calculated as 69.1 and 81.4. Then, the Energy sustainability indicator (ESI) is computed and the value is 0.849. According to the sustainable standard (the eligibility standard is 1), the ESI is close to 1, which illustrates that the whole building system needs continuous improvement in order to improve its sustainability.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Item** & **Data** & **Unit** & **UEVs** & **UEVs Unit** & **UEVs Ref.** & **Emergy (sej)** \\ \hline Updated Scenario 1 & & & & & \\ \hline PVC & 1.14\(\times\) 10\({}^{4}\) & Kg & 2.22 \(\times\) 10\({}^{11}\) & Sej/kg & [71] & 2.53 \(\times\) 10\({}^{15}\) \\ \hline Cement & 4.72 \(\times\) 10\({}^{5}\) & Kg & 2.94 \(\times\) 10\({}^{12}\) & Sej/kg & [46] & 1.39 \(\times\) 10\({}^{18}\) \\ \hline Water & 9.52 \(\times\) 10\({}^{6}\) & Kg & 2.67 \(\times\) 10\({}^{9}\) & Sej/kg & [46] & 2.54 \(\times\) 10\({}^{16}\) \\ \hline Diesel fuel & 6.76 \(\times\) 10\({}^{6}\) & Kg & 1.36 \(\times\) 10\({}^{5}\) & Sej/kg & [46] & 9.19 \(\times\) 10\({}^{11}\) \\ \hline Updated Scenario 2 & & & & & \\ \hline Bricks & 5.67 \(\times\) 10\({}^{4}\) & Kg & 2.03 \(\times\) 10\({}^{11}\) & Sej/kg & [46] & 1.15 \(\times\) 10\({}^{16}\) \\ \hline Concrete & 3.71 \(\times\) 10\({}^{5}\) & kg & 1.19 \(\times\) 10\({}^{12}\) & Sej/kg & [46] & 4.41 \(\times\) 10\({}^{17}\) \\ \hline Diesel fuel & 4.48 \(\times\) 10\({}^{6}\) & Kg & 1.36 \(\times\) 10\({}^{5}\) & Sej/kg & [46] & 6.09 \(\times\) 10\({}^{11}\) \\ \hline Updated Scenario 3 & & & & & \\ \hline Glass & 6.15 \(\times\) 10\({}^{4}\) & Kg & 1.69 \(\times\) 10\({}^{12}\) & Sej/kg & [71] & 1.04 \(\times\) 10\({}^{17}\) \\ \hline Aluminum & 2.36 \(\times\) 10\({}^{1}\) & Kg & 9.65 \(\times\) 10\({}^{11}\) & Sej/kg & [46] & 2.28 \(\times\) 10\({}^{13}\) \\ \hline Copper & 1.73 \(\times\) 10\({}^{1}\) & Kg & 1.52 \(\times\) 10\({}^{12}\) & Sej/kg & [46] & 2.63 \(\times\) 10\({}^{13}\) \\ \hline Diesel fuel & 9.24 \(\times\) 10\({}^{6}\) & J & 1.36 \(\times\) 10\({}^{5}\) & Sej/J & [46] & 1.26 \(\times\) 10\({}^{12}\) \\ \hline \end{tabular}
\end{table}
Table 1: Energy of building renewal stage.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**No.** & **Indictors** & **Values** & **Unit** \\ \hline
1 & Renewable input (R\({}_{\text{i}}\)) & \(9.38\times 10^{18}\) & Sej \\ \hline
2 & Nonrenewable resource (N\({}_{\text{s}}\)) & 7.64 \(\times\) 10\({}^{20}\) & Sej \\ \hline
3 & Energy feedback input (E\({}_{\text{f}}\)) & 1.14 \(\times\) 10\({}^{19}\) & Sej \\ \hline
4 & Energy yield ratio (EYR) & 69.1 & - \\ \hline
5 & Environmental loading ratio (ELR) & 81.4 & - \\ \hline
6 & Energy sustainability indicator (ESI) & 0.849 & - \\ \hline \end{tabular}
\end{table}
Table 2: Energy indexes list.  
In Figure 9, the change ranges of sustainability indicators have been visualized. Therein, the ESI indexes proportion of the renewal stage displays evident improvements from the original scenario (from 0.56/0.58/0.57 to 0.44).