New 2021 Washington State Energy Code

The 2021 Residential Washington State Energy Code (WSEC-R), which is set to be mandatory beginning July 1, 2023, includes several updates that significantly increase stringency for new homes in Washington. Here are a few of the major changes compared to the previous 2018 WESC-R:

Water heating

Under the 2021 WSEC-R, newly constructed homes must have a heat pump system installed as the home’s primary water heating source.

 Space heating

The 2021 WSEC-R explicitly states that, “space heating shall be provided by a heat pump system.” Limited exceptions to this requirement are available but are unlikely to apply except in rare instances.

Wall insulation

Builders have a few options to choose from when considering wall insulation in compliance with the new code. Continuous insulation must be installed on the exterior, prescriptively, but it is possible to achieve this requirement using alternative pathways to meet wall insulation compliance, such as advanced wall systems and high-performance windows.

Electric vehicle-ready circuit

The 2021 WSEC-R requires installation of a 40-amp electric-vehicle ready circuit.

Given the stringency of the new 2021 WSEC-R, Energy Trust of Oregon is currently evaluating its impact on all incentive offerings for SW Washington homes permitted under the new code.

As a reminder, Energy Trust currently offers incentives for builders who build new homes with NW Natural gas as the primary heat source. This offering will continue for participating homes that are permitted under the 2018 WSEC-R.  Builders can also apply for incentives if they install qualifying gas fireplaces and/or smart thermostats paired with a gas furnace. Visit the SW Washington new homes page for more information.

For details about the 2021 WSEC, visit the Washington State Building Code Council’s website. Always check with your local jurisdiction if you have a question about how to interpret code requirements.

If you have questions about the EPS New construction incentive offering in SW Washington, contact Greg Lasher, EPS field account manager.