## 4 Analysis of Zero Carbon Performance in Production Stage
### Establishment of EPD Database of Major Materials
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Classification System** & **Utilized Data** & \multicolumn{2}{c}{**Analysis Result**} & **Selection Result** \\ \hline Region & Green Standard for Energy and Environmental Design & - & Capital area, 65\% & \multirow{2}{*}{Capital area} \\  & (G-SEED) certification & - & Metropolitan, 14\% & \\  & (G-SEED) certification & - & Provincial city, 21\% & \\ \hline Building purpose & G-SEED certification & - & Business facilities, 32\% & \multirow{2}{*}{Residential: Apartment houses} \\  & & - & Apartment houses, 28\% & \multirow{2}{*}{Non-residential: Business facilities} \\  & & - & Schools, 16\% & \\  & & - & General buildings, 15\% & \\  & & - & Accommodation facilities, 4\% & \\  & & - & General houses, 4\% & \\  & & - & Sales facilities, 1\% & \\ \hline Structural form & G-SEED life cycle assessment & - & RC structure, 75\% & \multirow{2}{*}{RC structure} \\  & (LCA) certification & - & Steel-reinforced concrete & \\  & & - & structure, 14\% & \\  & & - & RC + steel structure, 18\% & \\ \hline Structural scale & G-SEED LCA certification & - & Average total floor area of & \multirow{2}{*}{Total floor area, 99,119.31 m\({}^{2}\)} \\  & & - & Average total floor area of & \multirow{2}{*}{Total floor area, 19,275.24 m\({}^{2}\)} \\  & & - & 41 business facilities & \\ \hline Building Lifespan & G-SEED LCA guideline & - & 50 years (assuming same energy & \multirow{2}{*}{50 years} \\  & & usage each year) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Four classification systems for the reference building. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Major** & **Detailed** & **Certifications** & **Lowest (1)** & **Average (2)** & **Highest (3)** \\ \hline \multirow{4}{*}{Ready-mixed concrete} & 18 MPa & 12 & \(1.08\times 10^{2}\) & \(1.91\times 10^{2}\) & \(2.72\times 10^{2}\) \\  & 21 MPa & 163 & \(1.12\times 10^{2}\) & \(2.25\times 10^{2}\) & \(3.22\times 10^{2}\) \\  & 24 MPa & 214 & \(1.01\times 10^{2}\) & \(2.39\times 10^{2}\) & \(3.87\times 10^{2}\) \\  & 27 MPa & 164 & \(1.59\times 10^{2}\) & \(2.71\times 10^{2}\) & \(3.88\times 10^{2}\) \\  & 30 MPa & 132 & \(1.70\times 10^{2}\) & \(2.83\times 10^{2}\) & \(4.05\times 10^{2}\) \\  & 35 MPa & 63 & \(1.67\times 10^{2}\) & \(2.99\times 10^{2}\) & \(3.95\times 10^{2}\) \\  & 40 MPa & 22 & \(2.67\times 10^{2}\) & \(3.73\times 10^{2}\) & \(3.73\times 10^{2}\) \\ \hline \multirow{2}{*}{Rebar} & Steel bars for reinforced concrete (RC) & 2 & \(4.54\times 10^{-1}\) & N/A & N/A \\ \hline \multirow{2}{*}{Masonry} & Concrete brick & N/A & N/A & N/A & N/A \\  & ALC block & 4 & \(2.77\times 10^{2}\) & \(3.03\times 10^{2}\) & \(3.37\times 10^{2}\) \\ \hline \multirow{2}{*}{Insulation} & Fiber insulation & 3 & \(4.68\times 10^{0}\) & \(5.43\times 10^{0}\) & \(6.19\times 10^{0}\) \\  & EPS & 3 & \(2.40\times 10^{2}\) & \(3.36\times 10^{0}\) & \(4.64\times 10^{0}\) \\  & XPS & N/A & N/A & N/A & N/A \\ \hline \multirow{2}{*}{Aggregate} & Sand & N/A & N/A & N/A & N/A \\  & Gravel & N/A & N/A & N/A & N/A \\ \hline \multirow{2}{*}{Stone} & Granite & N/A & N/A & N/A & N/A \\ \hline \multirow{2}{*}{Cement} & Cement & 4 & \(8.83\times 10^{2}\) & \(9.24\times 10^{2}\) & \(9.65\times 10^{2}\) \\  & Mortar & 3 & \(1.99\times 10^{-1}\) & \(2.41\times 10^{-1}\) & \(2.83\times 10^{-1}\) \\ \hline \multirow{2}{*}{Gypsum board} & Square edge-type board & 3 & \(5.92\times 10^{-1}\) & \(6.62\times 10^{-1}\) & \(7.03\times 10^{-1}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: CE ranges (kgCO\({}_{2}\)e/m\({}^{2}\)) of EPD-certified products for major construction materials. rebar, the lowest, average, and highest values were applied consistently. Additionally, concrete brick, extruded polystyrene insulation, aggregates, and stones were excluded from the A1-A3 CR analysis due to the absence of EPD-certified products. Table 5 presents the lowest, average, and highest CE values for each product in the EPD DB.