Under Boulder’s Energy Conservation Code, commercial buildings must achieve energy performance significantly exceeding national code baselines. Permit applications for commercial buildings larger than 20,000 square feet must utilize predictive computer modeling to demonstrate energy performance that is at least 30% better than ASHRAE/IENSA Standard 90.1. Permit applications for commercial buildings of 20,000 square feet or less may demonstrate energy code compliance by predictive modeling, but are also allowed to utilize approved prescriptive standards that achieve energy performance of at least 30% better than the 2012 edition of the IECC.