Analyzing the Environmental Impacts and Empirical Limitations of Green Remodeling with Life Cycle Assessment

The Government of Korea uses green remodeling (GR) as a central policy for achieving carbon neutrality in the building sector. However, despite GR's energy-saving benefits, it raises embodied carbon (EC) due to the incorporation of new materials, and there is a lack of impact analysis and assessment research. Thus, this study established the GR-LCA methodology to evaluate the environmental impacts (EIs) of GR, including EC. The methodology disaggregated and assessed the effects of EC and energy on GR in terms of GR's proportion of EC, six EI categories, and the carbon reduction impacts. The analysis revealed that GR's EC accounted for 10.6%, reducing to 9.89% when EPD materials were used. In terms of the reduction impact across six EIs, GWP was reduced to 0.84 and EP to 0.96. However, ODP, ADP, AP, and POCP, all elevated by high EIs from material inputs, increased to 626.7, 1.04, 1.16, and 250.09, respectively. Ultimately, the carbon reduction in GR was 24.9% when considering only energy usage, and 16.1% when including EC. When EPD materials were applied, the efficiency of reduction improved by an additional 0.6%, indicating a minimal application effect. Based on these findings, the differences in GR's EC compared to new constructions, reduction limitations, and potential improvements were discussed.