Washington state building code changes designed to get more electric heat pumps installed in newly built houses, apartments and commercial buildings are still on track to take effect mid-month after a judge on March 8 declined an industry-backed request to put the rules on hold.

Construction trade groups and others are challenging the code rewrite in Thurston County Superior Court, arguing that the State Building Code Council overstepped its authority in adopting it. Those who brought the case and other critics describe the new rules as effectively banning natural gas in new construction and say the revisions will lead to higher costs that will get passed to residents.

Environmental groups and other supporters of the code update say that by incentivizing electric heat pumps over natural gas the rules are an important step to combatting climate change. Fossil fuel emissions tied to buildings, they note, are one of the largest sources of carbon pollution after transportation.

Friday’s ruling was only on a request to pause the rules while litigation continues. An underlying court challenge is still alive.

Thurston County Superior Court Judge Carol Murphy emphasized that the court was weighing in on procedural aspects over how the new rules were adopted, not on policy questions related to the rewrite.

The code update is scheduled to take effect March 15.

Part of it has to do with required energy efficiency credits for construction. The credit system in the new rules favors electric heat pumps. Supporters say this amounts to a perk for builders to use a more environmentally friendly technology while leaving some flexibility. Opponents argue that the credits are so tilted against natural gas that it’s pretty much precluded as a heating option.

The lawsuit makes a case that the Building Code Council exceeded its powers in adopting the rules. It did so, the suit says, after proposals backed by Gov. Jay Inslee to take similar steps failed in the Legislature. The council includes 15 members appointed by the governor. The challengers in the case also contend the council violated rule-making procedures as it completed its code update.

This is not the first legal drama to unfold over heat pump and natural gas provisions in the code.

Groups and businesses behind the current case sued last year over a previous version of the rules that would’ve put even tighter restrictions on natural gas and propane.

The council last May hit pause on those rules taking effect after the U.S. 9th Circuit Court of Appeals ruled in April that similar regulations in the city of Berkeley, California were not allowed under federal law. In the months that followed, Washington’s Building Code Council settled on the current rewrite.

Last July, in a separate lawsuit, a U.S. district court judge in eastern Washington denied a gas industry attempt to block implementation of the building code update.

Environmental groups, such as the Sierra Club, say litigation over the rules is part of an industry-backed strategy to gum up efforts by states like Washington to move away from fossil fuels.

This story is republished from the Washington State Standard, a nonprofit, nonpartisan news outlet that provides original reporting, analysis and commentary on Washington state government and politics.