Development of building benchmarking index for improving gross-floor-area-based energy use intensity

Abstract

Energy benchmarking is essential for evaluating building performance and developing energy reduction strategies, typically using floor-area-based energy use intensity (EUI). However, this method has limitations. Studies show that metrics such as site energy, source energy, and CO2 emissions can produce varying benchmark results for the same building, raising concerns about reliability. As carbon reduction in buildings becomes increasingly important, there is a need for comprehensive indicators that assess both energy and carbon efficiency. This study introduces the Building Performance Index (BPI), that integrates energy and carbon emission efficiencies. Using a database of all buildings in Seoul, South Korea, we compared five BPI variants: conventional floor-area-based BPI, floor-area-based BPI adjusted for floor area ratio, volume BPI based on floor area, volume BPI adjusted for floor area ratio, and volume BPI based on building footprint. These were evaluated based on six criteria, including model simplicity, sensitivity analysis, data reliability, and indicator stability. While the relative importance of these criteria was not prioritized, this study proposes a shift from traditional two-dimensional metrics to more comprehensive three-dimensional volume-based metrics, offering practical guidance for decision-makers in selecting more reliable benchmarking methods.