Oregon and Washington code updates


Oregon and Washington are both seeing changes in building code. Oregon Residential Specialty Code changes went into effect on October 1, 2023. Washington code changes will take effect on March 15, 2024. Additional details are outlined below.

2021 Residential Washington State Energy Code (WSEC-R)

On Friday September 15, the Washington State Building Code Council voted to revise the effective date of the 2021 WSEC-R to March 15, 2024. In addition to this revision, the council voted to move the energy code changes to public comment. For more information about the WSEC-R, visit the Washington State Building Code Council’s website.

2023 Oregon Residential Specialty Code (ORSC)

The 2023 ORSC went into effect and was published on October 1, 2023. Below are a few of the major changes compared to the 2021 ORSC.

Distribution ducts

The 2023 ORSC requires distribution ducts for the HVAC system to be inside the building’s thermal envelope. There is an exception for builders to deeply bury distribution ducts in insulation instead. However, builders who claim this exception are required to implement two measures from the Additional Measures Table instead of just one, as required by the 2021 ORSC.

Air handler location

The 2021 ORSC allowed for air handlers to be installed in a crawlspace or attic. The 2023 ORSC now requires air handlers to be located inside the building’s thermal envelope in all situations.

Ductwork allowance

In the past, there was an allowance for up to 5% of ductwork to be located outside the building’s thermal envelope. In the 2023 ORSC, this has been simplified by changing the maximum outside allowance to 10 feet.

Beginning on April 1, 2024, all new permits must meet the 2023 ORSC. Energy Trust EPS New Construction will not require homes to be modeled against the 2023 ORSC until the new offer is launched in January 2025. Builders have until the end of December 2024 to submit their homes for EPS incentives using the 2021 ORSC.

To prepare for the 2023 ORSC and qualify for EPS New Construction incentives, builders should contact an EPS verifier to identify above-code measures best suited to their homes. Builders can also attend Energy Trust’s Builder Webinar to get additional insight into the 2023 ORSC.

For more details about the 2023 ORSC, visit the Oregon Building Code Division’s website. If you have a question about how to interpret code requirements, be sure to check with your local jurisdiction.