From Prescriptive to Outcome-Based — The Evolution of Building Energy Codes and Standards in China
China consumes approximately 20% of its primary energy in its building sector. It is estimated that energy use in Chinese buildings will continue to increase in the future due to the fast urbanization process. Codes and standards are widely believed to be one of the most effective ways to improve efficiency and reduce energy use and CO2 emissions in the building sector. China started to develop its own prescriptive building energy codes and standards in the late 1980s. Using the 1980s buildings characteristics as the baseline, the national prescriptive building codes in China have achieved 50% and 65% improvement in energy efficiency compared with the 1980s baseline. However, buildings that meet prescriptive code requirements may not yield actual operation energy performance. Many buildings demonstrate good energy performance during design but then do not perform well during operation. In order to fill in the performance gap between prescriptive standards and actual performance, China has developed an outcome-based building energy standard aimed at regulating actual building energy use in buildings.
This paper reviews international best practices on outcome-based building codes and standards. Based on previous studies of prescriptive building energy standards in China, this paper presents the gaps between China’s prescriptive standard performance and the proposed outcome-based standard requirements. To fill the gaps, the paper discusses certain operation measures that influence building energy use in the operation stage, and possible solutions to help buildings comply with prescriptive code performance to meet the proposed outcome-based standard requirements as well. Finally, this paper discusses current barriers and feasible policies to solve the issues of compliance and enforcement of the proposed outcome-based codes and standards.