*4.3. Comprehensive Analysis*

An analysis of the CO2 emission characteristics for each stage of the apartment construction process by work type is shown in Table 5. The total CO2 emission characteristics by each stage in the construction process are shown in Figures 5–8.


**Table 5.** CO2 emission by work type analysis in the apartment housing construction.

An assessment of each stage of the construction process showed that reinforced concrete work was the work type with the highest proportion of CO2 emissions, and after analyzing the total CO2 emissions characteristics of the entire construction process, most of the CO2 emissions of reinforced concrete work stemmed from the transportation stage. An assessment of the amount of CO2 emissions in the construction process by each stage showed that the total emissions from reinforced concrete work was 8.83 kg-CO2/m2, which was around 73% of the entire amount of CO2 emissions. Of this, 89% was from the transportation stage, and the total proportion of CO2 emissions during the construction stage was about 36%. Also, the construction waste transportation proportion was around 57% in reinforced concrete work at the disposal stage, and although the amount of CO2 emissions from all work types was small, an analysis showed that CO2 emissions were abundant during the process

of incinerating wallpaper and other materials used in wood work and other interior finishing work. The amount of CO2 emissions released from plaster boards and insulation materials in the landfill process was abundant in the order reinforced concrete work, wood work, masonry work, and tile work. By analyzing CO2 characteristics from the apartment housing construction process, we believe that activities to reduce CO2 emissions must begin by managing the load distance between the construction site and concrete manufacturer when collecting concrete for reinforced concrete work, and by managing the fuel efficiency of concrete transportation vehicles. It is expected that the assessment process of CO2 emission during the construction phase based on the apartment housing evaluation done in this research would be applicable in other studies in South Korea as well as other countries. However, the regional applicability range could be comparatively limited as the established data base of the research is based on the actual data of multi-unit dwellings that are built in South Korea.

**Figure 5.** Work type CO2 emission in transportation stage.

**Figure 6.** Work type CO2 emission in construction stage.

**Figure 7.** Work type CO2 emission in disposal stage.

**Figure 8.** Work type CO2 emission in construction process.
