Benchmarking energy use can help building owners and managers to assess building energy performance and to identify energy efficiency opportunities. With the advance information technologies, many countries have provided databases, tools, and evaluation frameworks to compare buildings to standards or peer-group and to assess energy performance based on real energy data collection. Energy consumption data make it easy to understand the energy use characteristics of each building, and can promote occupants' awareness of building energy efficiency when providing an energy performance index developed from these data. As a way of improving energy efficiency in the building sector, the Korean government has developed a nation-wide integrated energy consumption database with more than 6 million building records. The purpose of this paper is to introduce the framework of the national building energy consumption database and to analyze energy use characteristics of ofice buildings across the country. The prediction model derived from this study could be used to review the effects of energy efficiency policies and set a benchmarking for energy performance.