In 2024, Washington citizens voted to prohibit the legislature from banning natural gas, by adopting Initiative 2066. The efficacy of that vote was immediately challenged on appeal by a variety of clean energy and environmental organizations, King County, and the City of Seattle, who collectively argue the Initiative was unconstitutional on procedural grounds.  Essentially, plaintiffs contend the Initiative includes multiple impermissible subjects; did not fairly apprise voters of the subjects of I-2066; and is incomplete and improperly amends existing laws without setting forth those amendments in full. The Superior Court granted summary judgment in favor of plaintiffs and against defendants, and that decision will be argued before the Washington Supreme Court on January 22, 2026.

Whether plaintiffs succeed in that litigation, though, may not be the end of the story.  The United States filed a lawsuit on January 5, 2026, asking to have the natural gas building codes of the cities of Petaluma and Morgan Hill declared preempted by the federal Energy and Policy Conservation Act (the “EPCA”). The city codes at issue prohibit the use of natural gas in new construction, except in certain specified circumstances.  See United States complaint. The United States argues the EPCA preempts “state and local regulations that are stricter than (and therefore would effectively supersede) a federal standard, but more broadly any regulation ‘concerning the energy efficiency, energy use, or water use of’ products subject to a federal standard. Id. § 6297(c).” This means regulation or requirement in a “State or local building code for new construction concerning the energy efficiency or energy use of” a product regulated by the EPCA is preempted unless they satisfy seven conditions outlined within the EPCA. One of those conditions requires that the State or local “code does not require that the covered product have an energy efficiency exceeding the applicable energy conservation standard established” under the EPCA.

The Washington State Building Code Council (SBCC) adopted a variety of building code regulations in 2023 designed to reduce, if not prohibit, the use of natural gas in new construction projects. After the 9^th Circuit Court of Appeals ruled that federal law preempted the City of Berkeley’s ban on installing natural gas piping in new construction, in California Restaurant Association v. City of Berkeley, the SBCC delayed implementation of Washington’s natural gas-related building codes for 120 days in May 2023. The purpose of this delay, they said, was to review the codes, specifically, to reduce the risk of their being preempted by the EPCA.

Undoubtedly, those challenging the veracity and enforceability of Washington’s natural gas-related building codes are paying attention and will be anxious to see how United States v. City of Morgan Hill and City of Petaluma turns out. It may portend yet another challenge to the State’s efforts to regulate, reduce, or ban the use of natural gas through its energy regulations.

This article summarizes aspects of the law and opinions that are solely those of the authors. This article does not constitute legal advice. For legal advice regarding your situation, you should contact an attorney.