Engineered Systems, Feb. 2017.
http://www.esmagazine.com/articles/98173

"More than 30% energy savings can be achieved using the 2016 version of Standard 90.1, according ASHRAE. The savings was found during a recent analysis conducted by Pacific Northwest National Laboratories (PNNL) in support of the U.S. Department of Energy (DOE) Building Energy Codes Program."