Washington State Building Code Council files proposed energy code amendments, targets 20 November adoption

The Washington State Building Code Council (SBCC), a state-level body, filed CR-102 proposed rules for the 2024 Washington State Energy Code - both the Commercial and Residential editions - on 1 July 2026. The public comment period closed on 7 August 2026 following hearings held on 5 August and 7 August. Final adoption is targeted for 20 November 2026. No effective date has been set; the CR-102 is a proposed rule, not a final one.

What the proposed amendments cover

The CR-102 filing proposes amendments to the 2024 editions of the Washington State Energy Code - Commercial (WAC 51-11C) and Residential (WAC 51-11R). According to the Northwest Gas Association's public comments submitted 4 August 2026, the proposed rules would significantly accelerate electrification of building heating and water heating while discouraging technologies that use both electricity and natural gas. The residential cost-benefit analysis filed with the CR-102 recommends adoption of amendments including tightened air-sealing requirements and updated heat-recovery ventilation efficiency thresholds - specifically, a proposed increase in HRV/ERV efficacy from 1.2 to 1.7 cfm/W under proposed amendment RE-049.

The SBCC's own notice acknowledges that the energy codes must satisfy multiple, sometimes competing, statutory requirements: increasing energy efficiency, meeting cost requirements, following a public process, and complying with the requirements of Initiative 2066.

The I-2066 complication

Initiative 2066, approved by Washington voters in November 2024, would have prohibited the SBCC from discouraging or penalizing the use of natural gas in any building and required utilities and local governments to provide natural gas to eligible customers. A King County Superior Court judge struck it down in March 2025 as unconstitutional, ruling it violated the state constitution's single-subject rule. The Building Industry Association of Washington appealed directly to the Washington Supreme Court, which heard oral arguments on 22 January 2026. As of July 2026, the court had not issued a decision and gave no timeline for one.

The SBCC has stated publicly that there is confusion over how the energy codes should be enforced given the passage of I-2066 and that the council has debated the matter at length. The legal status of I-2066 remains unresolved, and the determination of how its provisions interact with the proposed CR-102 amendments belongs to the authority having jurisdiction - in this case, the SBCC and, ultimately, the courts.

Parallel code adoption track

The SBCC is running a separate rulemaking on the same schedule. It filed CR-102 for the 2024 International Building Code, International Residential Code, International Mechanical Code, International Fire Code, and Uniform Plumbing Code on 5 May 2026. Public comment on those codes closed 12 June 2026. Final adoption for the IBC, IRC, IMC, IFC, and UPC is targeted for 16 October 2026.

Trades affected by the energy code rulemaking include:

• Mechanical and HVAC contractors installing space-heating and water-heating equipment in new commercial and residential buildings
• Builders and general contractors responsible for building envelope compliance
• Plumbing contractors where water-heating system selection is affected

What to watch

The Washington Supreme Court's ruling on I-2066 could materially alter the legal landscape before the SBCC reaches final adoption on 20 November 2026. If the court reinstates the initiative, the SBCC would face statutory constraints on any energy code provision that could be read as discouraging natural gas. Practitioners should monitor the court's docket and the SBCC's November meeting agenda for any revision to the proposed CR-102 text before the CR-103 final rule is filed.