The Northwest Energy Efficiency Alliance (NEEA) contracted NORESCO, LLC. to conduct the 2018 Washington State Energy Code – Commercial (WSEC-C 2018) savings analysis. The WSEC 2018 was developed by the Washington State Building Code Council to replace the previous 2015 WSEC and was adopted statewide for commercial construction permitted as of February 1, 2021.
The commercial provisions section of WSEC 2018 impacted all types of commercial buildings and multifamily buildings over three stories tall. The 2018 edition added several new requirements with the most notable being the total system performance ratio (TSPR) requirement for HVAC systems, reduction of the interior and exterior lighting power allowances, and improved fenestration performance. This study was designed to quantify the energy savings resulting from adoption of the commercial provisions of the WSEC 2018 in new buildings and additions.
The analysis also evaluated the 2018 WSEC energy savings relative to the 2006 WSEC to determine progress toward Washington state’s legislative goal of reducing annual net energy consumption for commercial buildings under the 2030 energy code by 70% relative to the 2006 WSEC. Findings from the study show that the statewide increase in stringency between the 2018 and 2015 WSEC on a site energy basis was 7.7%. The analysis also shows that progress toward Washington’s 2030 legislative goals is being made with the 2018 WSEC saving 28% of site energy relative to the 2006 WSEC.