In an effort to improve the energy efficiency of existing buildings, it is necessary to first evaluate the energy performance of those buildings. Since it is difficult to obtain detailed information on existing buildings, the challenge is how to conduct reliable energy performance assessments with this limited information. As a result, many countries have adopted evaluation systems based on measured energy consumption data for existing buildings. This study aims to analyze the building energy consumption and characteristics using Korea’s national building database and provide an energy performance benchmark for continuous management of the energy performance of existing buildings. We analyzed the relationship between the basic statistical characteristics of the information collected from the national integrated energy database and energy consumption. The total floor area was found to be closely related to energy consumption, and various regression analysis methods were applied and compared to develop a benchmark to explain the trends of energy consumption according to the increase in total floor area. Finally, the developed benchmarks were used to evaluate energy consumption and examine the feasibility of the benchmarks.

With growing awareness of the need to reduce greenhouse gas emissions, much effort has been made to achieve “sustainability” in the building sector. Across the globe, many architects and building owners are striving to realize mandatory or voluntary building certification, in order to affirm the environmental performance of their buildings. Various sustainable design strategies and green building technologies have been adopted to improve buildings’ environmental performance as well as to achieve higher levels of certification. These technologies and strategies could affect building occupants’ satisfaction as well as productivity. This paper presents the results of post occupancy evaluation (POE) surveys to investigate occupants’ awareness of various green building technologies and their satisfaction levels and causes of dissatisfaction for selected technologies. A questionnaire survey was conducted for an office building in Korea that had received the highest grades in rating and certification systems. Some technologies showed higher levels of awareness and satisfaction, but there were also a few technologies with lower levels of satisfaction than we had expected. If these technologies are applied to buildings in the future, after improvisation or modification based on the POE results, it could serve as an effective strategy to increase people’s satisfaction as well as improve environmental performance.

Building energy codes are key policy tools for improving building energy efficiency by defining the minimum requirement for the energy performance of new buildings. In Korea, the building energy code was focused on prescriptive criteria for a long time but is now gradually introducing performance criteria. However, switching to performance criteria is not straightforward because of the resistance of the market to abandoning the well-consolidated prescriptive criteria. The objective of this study is to derive appropriate measures to strengthen the prescriptive criteria and the performance criteria, considering both the energy-saving effect and the economic efficiency for new office buildings and educational buildings to increase the market acceptance of the building energy codes. To this end, the energy-saving effects of reference buildings resulting from the reinforcement of the prescriptive criteria in the past have been first analyzed. Then, based on the collected energy performance parameters and cost data, the economic efficiency relative to the energy saving deriving from the application of passive and active energy conservation measures (ECMs) were analyzed, and future building energy code’s reinforcement measures were derived.