The Northwest Energy Efficiency Alliance (NEEA) contracted Mike D. Kennedy, Inc. to conduct the 2015 Washington State Energy Code Savings (WSEC 2015) analysis. The WSEC 2015 replaced the previous 2012 Washington Commercial Energy Code (WSEC 2012). It was developed by the Washington State Building Code Council and adopted statewide for commercial construction permitted as of July 1, 2016. The commercial provisions section of WSEC 2015 impacted all types of commercial buildings and multifamily buildings over three stories tall. In addition, it contained major changes in requirements for lighting power allowances, reductions in fan power energy consumption, required some building types to have dedicated outdoor air system (DOAS)-based HVAC and increased additional efficiency option requirements. This study was designed to quantify the energy savings resulting from adoption of the commercial provisions of the WSEC 2015 in new buildings and additions.
Findings from the study show that adoption of the WSEC 2015 represented a substantial advance in new building energy efficiency. In fact, the analysis shows that WSEC 2015 achieves energy savings of 11.7% for site energy and 10.8% for source energy, respectively, compared to the WSEC 2012. The analysis also shows that WSEC 2015 generates substantial electric energy savings (10%) and fossil fuel savings (16.5%). Lastly, the analysis shows that the bulk of energy savings generated by the code provision changes are through the DOAS system requirements, interior lighting power, and the section C406 extra efficiency options.