(The Center Square) – The 9th Circuit Court of Appeals has denied a request to rehear a case in which the court overturned a city of Berkeley, Calif. ordinance restricting the use of natural gas in new construction. For opponents of new code regulations imposed by the Washington State Building Code Council, it’s a sign that their efforts to overturn it could prevail.

It’s the latest in a series of political chess moves between two opposing groups regarding the future use of natural gas in new residential and commercial buildings.  

A year ago, the SBCC approved new code updates that mandated the use of heat pumps in new constructions, effectively a ban on natural gas. Heat pumps are highly energy efficient but cost more to install, a factor many building advocates say would contribute to increased home costs if required. The Building Industry Association of Washington and several other plaintiffs – shortly after the SBCC vote – filed a federal lawsuit, claiming it exceeded the council’s statutory authority.

Several months later, the 9th Circuit Court ruled against Berkeley on the basis that the Energy Policy and Conservation Act preempts state and local entities from regulating energy use of natural gas appliances.

In response, the SBCC voted to delay implementation of its new code to make updates in response to the ruling, while BIAW dropped its lawsuit. A separate group also filed a lawsuit in the U.S. District Court for the Eastern District of Washington, but it was voluntarily dismissed in August.

Although it has yet to decide whether to file a lawsuit, BIAW argued in a press release statement that SBCC’s latest code updates approved late last year and set to take effect on March 15 still do not comply with the EPCA.

“The SBCC said they delayed code implementation to develop updated codes that wouldn’t violate EPCA,” BIAW General Counsel Ashli Tagoai said in a press release statement. “Then they adopted code modifications that continue to violate federal law by making it so cost-prohibitive to use natural gas they’re essentially banning its use.”