Evolving Codes in the Northwest Impact Installers

Sep 28, 2020

Energy codes are evolving in the Northwest, and ductless heat pumps will offer building contractors a path for meeting new requirements in at least one state. Washington state approved its latest code, which will give home builders an advantage in code compliance when they use heat pumps for heating and cooling in their homes. Oregon is currently in the process of deciding its new building requirements, but it is likely that ductless heat pumps will continue to offer builders a solution to meet the state’s next residential code. Idaho and Montana are both considering new codes that borrow from the 2018 International Energy Conservation Code (IECC) but implications for ductless heat pumps in new construction are uncertain.


Washington state has adopted their 2018 Washington State Energy Code (WSEC), effective February 1, 2021. Changes will likely lead to an increase in ductless heat pump adoption for new construction, which could lead to labor constraints in the retrofit installation market. Stakeholders may be aware that the WSEC is a version of the IECC with major amendments. Amendments in sections 406.2 and 406.3 direct builders to achieve points by adopting measures beyond the IECC base code. Section 406.2 applies a carbon adjustment to the point totals, requiring homes heated with electric resistance to acquire more points. However, when heat pumps are used for heating and cooling the home, the new code reduces the total points required for the home to comply. HVAC designers and distributors both indicate the manufacturing supply chain is well prepared for an increase in ductless heat pump purchases. For trade allies who work in both existing and new homes, there could be strain on available labor to meet new demand.

Did you know? If production builders in your trade ally network indicate they are not sure how to best guide sub-contractors toward Washington code compliance, you can reach out to the BetterBuiltNW team for production builder code support. Contact the team at, and they will be happy to engage you and your participating installers to make this transition as easy as possible.


Oregon decision makers are determining what to include in the upcoming Oregon Residential Specialty Code (ORSC). The Oregon Building Codes Division (BCD) and Oregon Department of Energy (ODOE) anticipate that a final ORSC proposal will be ready for review by mid-October of 2020. If both groups hold to this timeline, the new code will likely go live in April 2021. Historically, Oregon has required builders to choose additional efficiency measures beyond the prescriptive code from its list of envelope and equipment minimum requirements. If Oregon holds on to this requirement for builders, then ductless heat pumps will continue to provide builders with a solution for meeting code.


Over the past year, Idaho made plans to adopt the 2018 International Energy Conservation Code (IECC), effective January 1, 2021. Idaho’s adoption of the 2018 IECC includes minor amendments to the base code that appear unlikely to have a large impact on ductless heat pump installers and the supply chain. These changes are intended to help smooth adoption. For example, Idaho’s new code will require 20 percent of the homes built to have a unique compliance check for building tightness, lower than the IECC version requiring 100 percent of homes built to show compliance.


Montana is also considering 2018 IECC adoption in 2021, but discussions and planning are still underway. A more reliable driver of ductless heat pump adoption could be manufacturers’ efforts to provide the market with ductless heat pumps designed to meet demands from the state’s climate.

With three of the four states still deliberating on new requirements for residential building performance, changes in ductless heat pump demand could be ahead. Ductless heat pumps will nonetheless continue to offer home builders a high efficiency solution for residential heating and cooling. If new construction is occurring at relatively high rates in your service territory, consider checking in with your trade allies in 2021 to determine the size and capacity of your ductless installer network to help you manage the incentive pipeline for your conservation programs.