Performance Gap Analysis in The Context of Building Energy Efficiency Certificate in South Korea

Abstract

In South Korea, the building energy efficiency certification (BEEC) system has evaluated annual energy use intensity (EUI) using an evaluation tool, ECO2. ECO2 was developed by the Korean government based on ISO 13790 and DIN V 18599. However, a performance gap between the predicted and measured EUI exists due to many reasons including simplifications and modeling assumptions of ECO2, building operational and parameter uncertainty. With this in mind, the authors aim to analyze the performance gap between the predicted and the measured EUI for 302 buildings according to various building energy influencing factors such as building types, degree-days, etc. As a result, it is found that the performance gap is significant and has little correlation with the factors mentioned above. It also presented the limitations of EUI as the performance indicator in building energy assessment by showing the variation in the annual EUI of buildings. This indicates that in order to reach an objective national BEEC system, crucial attention must be paid to quantifying the performance gap in the design stage, accompanied by the development of new performance indicators and evaluation processes based on the uncertain characteristics of actual building energy.