## 6 Conclusions  
In this study, we analyzed the application of various framing methods to improve the economic feasibility of additional structural framing input, one of the obstacles to multi-trade prefabrication application. We analyzed their design, material, and fabrication costs. Based on the calculation results of the cost invested in each stage, the cost required only for PMR structural framing was at least 7.2% (Type E) and as high as 12.0% (Type D) of the total construction cost. An analysis was conducted to identify an economical method for structural framing, and the major analysis results are as follows:  
1. Design Cost Analysis: the cost incurred by the workforce for the design stage was 25.45-38.67% of the total structural framing cost. Even if the supporting interval was adjusted and the cube shapes repeated, such as in Type A, Type B, and Type C, the effect on the design cost was not significant. In Type E, the lowest cost input was observed despite designing the elements that support the MEP line individually. 2. Material Cost Analysis: 24.46-41.94% of the structural framing cost was spent on PMR framing. The material cost inputs of Type B and Type C, which pursued economic feasibility by increasing the supporting interval, were lower than that of others. Regarding material cost, Type E, in which the upper framing was removed and only the parts that require MEP supporting were designed, was the most economical. 3. Fabrication Cost Analysis: fabrication cost accounted for 25.47-49.92% of the total structural framing cost. Adjusting the supporting interval reduced the fabrication cost but did not generate a significant difference in the ratio of material quantity. This \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Phase** & & **Type A** & **Type B** & **Type C** & **Type D** & **Type E** \\ \hline Fabrication Cost (per cubic meter) & Labor Input (person-day) & 0.35 & 0.32 & 0.71 & 0.74 & 0.22 \\ Labor Cost & 196.2 & 196.2 & 196.2 & 196.2 & 196.2 & 196.2 \\ (USD per day) & 68.67 & 62.784 & 139.302 & 145.188 & 43.164 \\ Total Fabrication Cost & (USD) & (28.45\%) & (31.68\%) & (49.92\%) & (44.30\%) & (25.47\%) \\ Total Structural Framing Cost & 241.41 & 198.20 & 279.04 & 327.74 & 169.44 \\ (USD per cubic meter) & 144.26 & 148.65 & 163.24 & 180.26 & 107.41 \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._indicates that fabrication cost is not directly affected by quantity. Type C was identified to be disadvantageous in terms of fabrication cost. This suggests that simplifying the fabrication pattern may be more efficient than reducing the quantity. The most economical framing scheme was Type E, with decreased overall material quantity. The contributions of this finding to academia and industry are as follows. Existing studies have only compared the economics of PMR application or suggested additional effects that can be obtained from PMR application. In addition, some studies report that using PMR increases costs, whereas others report that it decreases costs. Economic feasibility can be improved through detailed changes in construction methods and the development of details. In PMR, structural framing incurs more than 7.2% of the total construction cost, and this study provided a systematic analysis that could improve the economic feasibility of structural framing. The analysis was conducted in terms of design, material, and fabrication costs. Another economic type of structural framing is possible by reflecting regional characteristics. This study inherited the limitations of case studies. It has a small sample size and aspects that are difficult to generalize. However, detailed PMR design options were presented, unlike the results reported in previous studies, and the effect of applying them was analyzed in detail. Through the analysis of the design stage and the manufacturing process in the factory, the input of labor was measured by time, and the input of materials was calculated.