Journal of the Korean Solar Energy Society ISSN:1598-6411(Print) 2508-3562(Online) 한국태양에너지학회 논문집

As global interest in building energy efficiency grows, South Korea has actively implemented the Building Energy Efficiency Rating Certification (BEEC). In this study, we analyzed all 13,370 BEEC-certified buildings from 2013 to 2025 to identify structural changes and characteristics across sectors, scale, and regions, with the aim of quantifying the determinants of top-rating certification grades. To achieve this aim, we used descriptive statistics, exploratory data analysis, logistic regression for determinant analysis, and a Python-based regression model to compare expected versus actual certification ratings. We found that that BEEC certification accounts for 34.1% and 65.9% of residential and non-residential buildings, respectively. Moreover, the practical spread of the certification system was led by non-residential buildings. Our results relieved improvement in energy efficiency qualitatively improved, with top-ratings (1++ and 1+++) comprising 62.2% of recent certifications (2021–2025). Logistic regression analysis showed that newer and public buildings are significantly more likely to achieve top-ratings grades, whereas residential buildings with larger gross floor areas are less likely to do so. Furthermore, the predictive model analysis confirmed that public offices and properties in Seoul and Gyeonggi-do often received lower-than-expected ratings compared to similar building groups. Overall, this study aimed to provide a comprehensive and quantitative evaluation of the BEEC system based on the data of the entire certified building and to provide practical policy insights in the implementation of the Zero Energy Building (ZEB) certification system.