## 3 Results of the Case Study
### GWP Values from Investigated Steel Products  
The GWP values of the investigated roofing and wall cladding metal products were calculated using the LCAQuick tool and the GWP Equation (1). The quantification focused on four life cycle modules, which were the production stages (A1-A3), the water processing stage (C3), the disposal stage (C4), and the potential carbon offset from recycling, reusing, and recovering processes (D). Table 3 presents the GWP values of the assessed building products by using the LCA approach. According to Table 3, the GWP values from different assessed metal products seem to vary. In terms of product life cycle modules, the production stages (A1-A3) were the most significant GWP emitters compared to the other selected modules. However, the recycling processes of the steel products could reduce the emissions from the production stages by \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Area** & **Site Address** & **Building Type** & **Metal Product Type** & \begin{tabular}{c} **Width of the** \\ **Metal Sheet** \\ **(mm)** \\ \end{tabular} & \begin{tabular}{c} **Linear** \\ **Meter of** \\ **Roof (m)** \\ \end{tabular} & \begin{tabular}{c} **Linear Meter of** \\ **Cladding (m)** \\ \end{tabular} \\ \hline Christchurch & 53 Glenmark Drive & Residential & Tray Roofing Profile & 630 & 524 & 906 \\ \hline Hamilton & \begin{tabular}{c} NZ Honey \\ Office-Warehouse \\ \end{tabular} & Commercial & Long Run 5 Ribs & 765 & 2328 & 1695 \\ \hline Palmerston & \begin{tabular}{c} 14 Popular Grove, \\ Keilding \\ \end{tabular} & Residential & Long Run 5 Ribs & 765 & 310 & 79 \\ \hline Tauranga & \
\begin{tabular}{c} 44 Marshall Rd, \\ Katikati \\ \end{tabular} & Commercial & Long Run 5 Ribs & 765 & 509 & 263 \\ \hline Wellington &
\begin{tabular}{c} 3 Ara Hekere \\ Waikanae \\ \end{tabular} & Residential & Tray Roofing Profile & 630 & 623 & 308 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Area** & **Site Address** & **Product Type** & \begin{tabular}{c} **Base Metal** \\ **Thickness (BMT)** \\ \end{tabular} & \begin{tabular}{c} **Global Warming Potential (GWP) (kgCO\({}_{2}\)eq)/m\({}^{2}\)** \\ \end{tabular} \\ \hline \multirow{6}{*}{Auckland} & 201 Lincoln Drive, & Long Run 7 & 0.40 mm and & 15.60 & 0.03 & 0.02 & \(-\)4.72 \\  & Henderson & Ribs & 0.55 mm & 14.21 & 0.03 & 0.02 & \(-\)4.42 \\ \cline{2-8}  & 59 Arabella Lane, & Tray Roofing & 0.55 mm & 14.21 & 0.03 & 0.02 & \(-\)4.42 \\  & Snells Beach & Profile & & & & & \\ \cline{2-8}  & 77 Rotu Drive, & Long Run 5 & 0.40 mm & 8.65 & 0.02 & 0.01 & \(-\)2.52 \\ \cline{2-8}  & 380 Cowes Road, & Tray Roofing & 0.55 mm & 17.60 & 0.04 & 0.03 & \(-\)5.91 \\  & Waikhee Island & Profile & & & & & \\ \cline{2-8}  & \begin{tabular}{c} Manawa View, \\ Kerikeri \\ \end{tabular} & Long Run 5 & 0.40 mm and & 15.61 & 0.03 & 0.02 & \(-\)4.81 \\ \hline Christchurch & 53 Glenmark Drive & Tray Roofing & 0.55 mm & 17.60 & 0.04 & 0.02 & \(-\)5.48 \\  & \begin{tabular}{c} NZ Honey \\ Office-Warehouse \\ \end{tabular} & Long Run 5 & 0.40 mm and & 17.91 & 0.04 & 0.02 & \(-\)5.39 \\ \hline Palmerston & \begin{tabular}{c} 14 Popular Grove, \\ Keilding \\ \end{tabular} & Long Run 5 & 0.40 mm and & 16.86 & 0.04 & 0.02 & \(-\)4.99 \\ \hline Tauranga & \
\begin{tabular}{c} 44 Marshall Rd, \\ Katikati \\ \end{tabular} & Long Run 5 & 0.40 mm and & 17.53 & 0.04 & 0.02 & \(-\)5.24 \\ \hline Wellington &
\begin{tabular}{c} 3 Ara Hekere \\ Waikanae \\ \end{tabular} & Tray Roofing & 0.55 mm & 20.53 & 0.04 & 0.03 & \(-\)6.35 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: GWP values of investigated specific metal products. up to 34%. For instance, the tray roofing profile with a pan width of 450 mm metal roofing and wall cladding products were attached to 380 Cowes Road, Waiheke Island, Auckland case building.