“We had originally thought Boulder would be the first” to ban gas hookups in new buildings, Christine Brinker of the Southwest Energy Efficiency Project (SWEEP) said. “But circumstances change.” Credit: Oregon State University

New research, published in December, found rates of childhood asthma were higher in homes with gas stoves. The peer-reviewed study was another piece of evidence indicating the dangers of gas and its effects on the climate and human health. Responding to the science, local governments across the country have accelerated their efforts to wean off gas. Already, nearly 70 cities in California alone have adopted gas bans or electrification ordinances since 2019. 

But Colorado has largely been absent from this conversation. 

Last year, Crested Butte, a small mountain town of roughly 1,700, became the first and only locality in the state to ban gas in new buildings. 

Now Boulder, a hub of climate research and solutions — the gas stove research came out of Rocky Mountain Institute, founded in Colorado, now with an office in Boulder — is joining the electrification conversation.

Boulder Mayor Aaron Brockett said the latest gas stove research only increases the council’s interest in exploring a gas ban in new buildings. “We already had it on the agenda for 2023 to consider requiring all-electric construction in new buildings when we update our building codes this year,” he said in an email. Right now, Boulder’s building codes sport an Energy Conservation Code and a Building Performance Ordinance, both of which aim to reduce building emissions, though not to the extent that an all-electric ordinance would.

Brockett added that until this point, the council’s interest in a gas ban was mostly for greenhouse gas reductions, to mitigate climate change. Boulder has a goal of shifting to 100 percent renewables by 2035.

“These new health reports add a significant additional reason to consider the change,” Brockett said. 

Gas stoves, like gas-powered furnaces and water heaters, emit methane — a short-lived but powerful greenhouse gas. They also abet a system of facilities and pipelines that leak the global warming pollutant into the atmosphere before it’s burned for cooking, heat or power. 

In Boulder, commercial buildings make up 45% of greenhouse gas emissions, with residential buildings adding another 16%. That’s in part due to gas. Xcel Energy, Boulder’s supplier of power, derives 29% of its energy from gas.

In Boulder County, the consideration of bans on gas in homes has been kicking around for some time. Ashley Stolzmann, the former mayor of Louisville and new Boulder County commissioner, used her time in Louisville’s city government trying to make her town the second locality in Colorado to ban gas hookups in new construction. 

“The climate impact is a health impact,” Stolzmann said. Louisville did not end up voting to electrify during Stolzmann’s tenure, adopting a voluntary code instead. They have since adopted all-electric space and water heating requirements for most commercial and multifamily buildings, similar to Denver. 

Stolzmann said later this year the county commissioners will be “taking up building codes generally” and would be looking to shift away from methane to hit the county’s goals.

Lafayette is having similar conversations. At a council meeting last December, councilmembers directed city staff to draft a building ordinance that would ban gas hookups in new builds with a few exceptions, like commercial kitchen uses. “Sixty-eight percent of greenhouse gas emissions in our city are from buildings,” said Tim Barnes, a councilmember. “We have to step up. This [ordinance] is the opportunity we’ve been waiting for.”

Lafayette Mayor JD Mangat told Boulder Reporting Lab he expects the council will unanimously approve the ordinance in the first quarter of this year. 

Biggest issue in Boulder is ‘tackling all of the existing homes with gas stoves’

Carolyn Elam, the energy system senior manager for the city of Boulder, has questioned the effectiveness of such a ban in Boulder, as “new construction represents a very small fraction of the buildings in Boulder.”

But responding to the news about the health impacts of gas stoves, Elam said the city is “following the evolving research very closely” and is working with researchers at CU, where investigation into indoor air quality has been happening for at least five years. Elam added that gas use in general will be a topic of consideration when the city updates its energy codes for 2023, echoing Mayor Brockett.

“The biggest issue, though, is tackling all of the existing homes with gas stoves,” Elam said. How to help people transition their appliances is the rub. Ithaca, New York has enacted gas bans on both new and old buildings, requiring retrofits. This has led to questions for how to fund those retrofits for its residents. The option for now in Boulder, for switching to electric stoves, is rebates, Elam said. Homeowners wanting to switch from a gas to electric stove can currently get a $200 rebate from the city and a $100 rebate from the county.

Changing minds about gas stoves is something that Elam said will be a focal point for the city over the next few years.

“People have been trained, through shows like Master Chef, that gas stoves are the best cooking surface and a sign of affluence,” she said. “When many people hear electric, they associate it with the technology of old.”

Elam said induction cooking is what the city wants to encourage people towards: stoves that use magnetic fields to heat pots without the cook-top getting hot, reducing the chance of burns while heating more efficiently than gas stoves.

Avoiding a patchwork of building codes across the Front Range

The Southwest Energy Efficiency Project, or SWEEP, has lately been mediating conversations between local governments along the Front Range on energy code updates. The driver of their work is “to get as close to net-zero emissions as possible” with the acknowledgment that “electrification is one of the best ways to get there,” according to Christine Brinker, senior buildings policy manger for SWEEP.  

SWEEP realized that having the same “or very very similar” building codes across much of the Front Range would make getting closer to net zero easier, as contractors wouldn’t have to navigate a patchwork of codes, and cities could learn from each other in code enforcement. 

Erie and Superior have adopted versions of SWEEP’s “cohort” code — one that encourages electrification but doesn’t require it. Lafayette, as mentioned above, is pursuing something more aggressive. Some other counties involved in the cohort are Boulder, Louisville and Northglen.

Boulder County is going to be close to last if it ends up passing it.

“We had originally thought Boulder County would be the first,” Brinker said. “But circumstances change.”

Brinker presented at the Lafayette City Council meeting where councilmembers decided to be more aggressive in emissions reductions. Brinker was able to speak to Xcel’s position in all this, the monopoly energy provider for Boulder. 

“They’re in a much better position than other utilities because they provide both natural gas and electricity,” Brinker said. Some 20 states have passed legislation banning local governments from enacting prohibitions on gas hookups. Gas utilities have heavily lobbied for the legislation. Brinker didn’t think Xcel would lobby against local bans, but probably wouldn’t support them either.

“[Xcel] seems to know that [electrification] is a direction a number of their communities are heading,” she said. 

“But it does seem like they’ve gotten a lot of flack, justified or not, for huge increases in natural gas bills from their customers,” she continued. “So I think that is probably causing the utility and homeowners to take a fresh look at what alternatives they would have to those high natural gas bills. One alternative would be electrification. Another would be more energy efficiency. Then those two can go hand in hand.”

Xcel did not respond to a request for comment.

Correction: The original version of this article said Louisville passed the SWEEP voluntary “cohort” code. In fact, Louisville adopted its own code amendments before the cohort received money from the state to begin coordination. Meaning, its code is unique from the rest. The city still joined the cohort to coordinate on future codes.  

Tim Drugan is the climate and environment reporter for Boulder Reporting Lab, covering wildfires, water and other related topics. He is also the lead writer of BRL Today, our morning newsletter. Email: tim@boulderreportinglab.org.

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  1. Re: Gas stoves
    Please clarify the difference between natural gas and propane. Mountain homes largely use propane for gas stoves and heating and fireplaces (if not a wood fireplace). In searching the difference on the internet it looks like propane is clean energy when it comes to emissions versus natural gas.

  2. If we go all-electric and the rest of the world doesn’t, how does that cure our environmental issues? What if the electric grid goes down and we do not have any source of heat inside the house, since banning of wood burning fireplaces and stoves are being sought after to ban? What about the high cost of electricity as your only source to operate your home? Much more expensive to the household than gas.

  3. Almost all natural gas furnaces, water heaters, and gas ovens still need electricity to run, so they don’t work in a power outage either. Even some gas stoves won’t work in a power outage even if you manually light them, because of the interlock safety feature. Most households will be without heat in a power outage regardless of their heating system type. That’s why the newer building codes require lots of insulation and low air-leakage rates, so households can “ride out” a power outage that lasts a few days and still be in livable temperatures. I’m not aware of any jurisdictions seriously looking to ban wood fireplaces or self-contained wood stoves so I think those are still an option. (Pollution limits for wood stoves have been in place for many years, but they don’t ban the systems.)

    As to energy bills, you might be thinking of the older electric resistance technology, not newer heat pump technology. Electric resistance costs more to run than systems burning natural gas, but heat pumps cost less. Most people recently have seen their gas bills double, making the economic case for all-electric even stronger. Our bills with our heat pump are lower than our neighbors, even during the sub-zero cold snap last month.

  4. If this is seriously considered, it would be nice to see the city produce a cost comparison of heating a home via heat pump as compared to the efficient gas furnaces required now (95% in Boulder?) in a well insulated new home over an average of recent natural gas prices rather than the exogenous price shock we’ve seen this season.

    Coupling that with the fact that, as shown in this piece, coal accounts for 1/3 of our electricity generation, it seems like electric heat and hot water from Xcel would be dirtier than natural gas as long as *any* coal is used.

    It seems like more focused change on commercial buildings that have no industrial use case for natural gas would make more sense given their emissions are nearly treble those of residential emissions.

  5. Given that something like 2/3 of Colorado’s electricity comes from non-renewable sources, fossil fuels, how is a ban on gas stoves—and presumably furnaces and water heaters at some point—a step towards 100% renewable? Emission reduction? Sure, but it’s still emitting greenhouse gases. Just the emissions are somewhere outside of Boulder.

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