The Northwest Energy Efficiency Alliance (NEEA) contracted Ecotope, Inc to estimate the energy savings of the 2018 Washington State Energy Code residential provisions (WSEC-R) compared to the 2015 and 2006 WSEC-R codes, as well as the 2018 International Energy Conservation Code (IECC). The 2018 WSEC-R code was developed by Washington State Building Code Council and has been adopted statewide for construction permitted as of February 1, 2021.
Findings from the study show that adoption of the 2018 WSEC-R energy code represents a substantial advancement in new building energy efficiency. Results show continued improvement in WSEC code performance, demonstrated by decreased energy usage and increased savings relative to comparison codes. For the 2018 WSEC-R this analysis estimates a 22% savings from WSEC 2015 and a 45% savings from WSEC 2006.
