California's top energy bosses soon will decide when to snuff out natural gas flames in new homes.

The seismic move toward omitting some gas appliances comes as the California Energy Commission retools state building codes for energy-efficient homes. It's an expansion of the state's first-in-the-nation mandates requiring solar panels on all new homes starting last year.

The agency now plans to tighten rules on natural gas for home heating and hot water, a code update that would take effect in 2023.

Environmental groups want a complete ban on natural gas in new homes, but the state commission has signaled that isn't likely right now. Officials instead in the coming months are likely to use incentives to urge developers to pick electric options for heating, like heat pumps. More muscular requirements could come later.

"We are really ratcheting up the efficiency across the board," agency Commissioner Andrew McAllister said in an interview. "We anticipate that we'll be providing incentives for the market to scale up its adoption of heat pumps."

"You need to give the marketplace reasons to adopt it before you step in and maybe mandate it," McAllister added. "That's the pathway that we're likely on."

The long-term outlook for natural gas isn't good in California, which wants to eliminate most carbon emissions by 2045. Gov. Gavin Newsom (D) injected urgency into state climate efforts this summer after wildfires scorched more than 4 million acres, a new record.

The California Building Industry Association, a trade group whose members develop 85% of new buildings in the state, is girding for ever-tougher rules over the next five years.

"The writing's on the wall," said Bob Raymer, technical director with the industry group. "They're going to want electric space and water heating come 2026."

The use of natural gas in buildings creates about 10% of California's greenhouse gas emissions, according to the California Air Resources Board.

That agency in November urged "stronger kitchen ventilation standards and electrification of appliances, including stoves, ovens, furnaces, and space and water heaters, in the 2022 code cycle for all new buildings."

Those moves would set new benchmarks nationally and are intended "to protect public health, improve indoor and outdoor air quality, reduce GHG emissions, and set California on track to achieve carbon neutrality," said CARB.

They come as more than 40 cities and counties in California have tightened rules on natural gas use in new homes. A few have banned it entirely, including San Francisco. Environmental groups are pushing to eliminate gas from new residential construction immediately, a move that they say would prevent new homes from releasing emissions for decades to come.

"We don't have another three years to wait on this," said Matt Vespa, an attorney at Earthjustice. "There's a lot of momentum here."

Even San Francisco-based utility Pacific Gas and Electric Co., which has 5 million customers, said that it supports "local government policies that promote all-electric new construction."

"PG&E welcomes the opportunity to avoid investments in new gas assets that might later prove underutilized as local governments and the state work together to realize long-term decarbonization objectives," the utility said in a statement.

2 agencies sued

Other power companies are defending gas.

Southern California Gas Co., the nation's biggest natural gas utility by sales revenue, sued the California Energy Commission, or CEC, in July over what the utility sees as a bid to marginalize gas.

The lawsuit targeted CEC's 2019 Integrated Energy Policy Report, a planning document. It argued that the agency failed to take a full look at natural gas in its report and omitted submitted comments. The result was to minimize the role of natural gas, the suit said, noting that other agencies rely on the state commission's assessment.

"California law requires the CEC to implement a balanced approach to California's complex energy needs that includes the use of natural gas," it said.

Meanwhile, the California Natural Gas Vehicle Coalition, funded in part by SoCalGas, sued CARB over its Advanced Clean Trucks regulation.

That rule required medium- and heavy-duty vehicle manufacturers to sell an increasing percentage of zero-emission trucks starting in the 2024 model year. The suit claimed that the rule would create "significant, short-term environmental impacts" by spurring construction of infrastructure to support new hydrogen fueling and electric vehicle charging stations.

SoCalGas, a subsidiary of Sempra Energy, did not respond to requests for comment on the building code update.

The California Building Industry Association hopes to shape the timing of natural gas restrictions. Raymer argues that state officials need to allot more time for developers and heat pump manufacturers and installers to shift toward electrification of buildings.

Heat pumps currently make up about 2% of residential heating units, he said. When the solar mandate took effect, solar was being installed on about 25% of homes, Raymer said.

California "has made it very clear it's decarbonizing, and that means both the new and existing housing stock is going to go through some major changes, the same thing for the commercial stock," Raymer said. "We get that."

But he said requirements to use heat pumps instead of gas appliances could increase costs for developers. CEC could offer builders an optional all-electric package that includes "slightly less stringent" energy efficiency requirements on attic and wall insulation.

That could "save the builder a small amount of money that can be used in making the switch away from gas to electric," Raymer said.

Architects and doctors

Architect Scott Shell said heat pumps are a known technology that are used all over the country. Installers are familiar with the equipment, he said, because it's roughly the same technology as air conditioners.

He's a member of the American Institute of Architects in California, whose board voted unanimously in 2018 to support a national and international energy standard that aims for carbon neutrality in new buildings.

The building industry's contention that heat pumps can't be widely used is "the weakest part of their argument," Shell said.

Electrification is also less expensive, he said. The University of California recently opted for all-electric buildings in its new student housing projects because those bids were the least expensive, he said.

"Anytime anybody has to do something a little bit different, there's a learning curve," Shell said of all-electric homes. "I don't think that learning curve is going to be any different three years from now. I don't think putting it off is going to help with that."

Many health professionals also support electrification.

Lisa Patel, a pediatrician at a San Francisco hospital, said children living in homes with natural gas cookstoves have a 24% higher risk of being diagnosed with asthma over their lifetimes and a 42% higher risk of experiencing asthma symptoms.

"I'm constantly struck by the fact that I've been living with gas stoves in my home for years," she said. "As a doctor, I should have known better. ... [S]o now that I know, I want to make as many other people know and that we really work toward getting these out of our homes."

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at