Impact of zero energy buildings on medium-to-long term building energy consumption in China

The future development pathway of upgrading building energy codes in China remains unclear. No studies have addressed the impacts of Zero Energy Building (ZEB) on medium-to-long term building energy consumption. By reviewing the development and enforcement of building energy codes in China in the last 30 years (1986-2016), together with the analysis of energy consumption of ultra-low energy building and nearly-zero energy building (nearly-ZEB) demonstration projects (2012-2017), this study proposes a three-definition hierarchy of ultra-low energy buildings, nearly-ZEB and ZEB as the successive building energy codes upgrading goals towards 2050. Six scenarios, BAU to leapfrog scenarios, are developed to study the building energy consumption from 2025 to 2050. The results show that the peak of the building energy consumption decreases and the occurrence time advances. In general, only if the ultra-low energy building, nearly-ZEB and ZEB account for more than 50% of total floor area does the building energy consumption begin to decrease. In moderate development scenario, which is most likely to occur, the peak will appear in 2035 with the amount of 567 million tce. Compared to BAU scenario, in leapfrog scenario, the accumulated saving of fossil fuels can be reduced by up to 9380 million tce till 2050, which contributes most to mitigation of climate change.