Economic Evaluation of Small Public Office Buildings with Class 1 of Zero Energy Building (ZEB) in Korea by Reflecting Life Cycle Assessment (LCA)

This study summarizes the technology level and economic feasibility of two small 500 m² public office buildings that achieved a first-class Zero Energy Buildings (ZEB) certification for the first time in Korea. In addition, a Life Cycle Assessment (LCA) reflecting the ZEB performance in the operation stage was analyzed, and the LCA factors considering the characteristics of small buildings were reviewed. Moreover, an economic analysis was performed through a Net Present Value (NPV) by reflecting the ZEB and LCA, and the results showed little economic feasibility. However, adding the environmental costs calculated through the LCA to the existing energy-saving costs could offset an additional 11.6–11.7%. Therefore, including the environmental impact and cost through these LCA evaluation techniques could be a positive step toward increasing the effectiveness of ZEB applications. This study is significant in that it conducted a comprehensive analysis through ZEB and LCA in terms of carbon reduction for small buildings that achieved a first-class ZEB certification, but it is limited to only two cases.