In a move that could have a significant impact on the state’s ability to make drastic cuts to its carbon emissions, state officials on Tuesday released a much-anticipated proposal for new building codes that would require new homes and offices to be far more energy efficient.

The controversial proposal, which also calls for sweeping changes to existing building codes, would require developers to use more energy efficient construction materials; install solar panels wherever possible; and among a range of other measures, wire new homes, offices, and other buildings with the necessary cables to enable them to use heat pumps and appliances that don’t use fossil fuels.

But some said the proposal doesn’t go far enough to end the use of oil and natural gas in future construction projects, as developers, in some cases, would still be allowed to install the necessary pipes and other infrastructure so their buildings could continue to use fossil fuels.

“The proposed updates to the state’s building codes seek to strike an important balance between energy efficiency in residential and commercial building construction, and continued housing production across the commonwealth, as the state works to reduce greenhouse gas emissions,” said Troy Wall, a spokesman for the state’s Executive Office of Energy and Environmental Affairs.

State lawmakers and environmental advocates welcomed the proposal, which was required by the state’s landmark climate law that took effect last year and mandates that the state cut its emissions by 50 percent below 1990 levels by the end of the decade and effectively eliminate them by 2050. But they hoped regulators would make changes to the proposal before the law requires it to be enacted by the end of the year.

“There’s real progress here, and yet I’m disappointed,” said state Senator Michael Barrett, a Lexington Democrat and one of the climate bill’s lead negotiators. “What is missing is significant. This proposal gives permission to put new natural gas infrastructure into the ground, when we know those assets will have to be abandoned to meet our climate goals.”

He added: “The Baker administration has kicked the proverbial can down the road, and I don’t know how long we can wait. This is a new lease on life for natural gas assets.”

Representatives for developers, who worry that any new building requirements could hike the costs of construction, said they would evaluate the state’s proposal carefully.

“There is no doubt that the proposed update will have an impact on development across the state,” said Tamara Small, chief executive of NAIOP Massachusetts, a lobbyist for developers and building owners. “We look forward to working with the administration and other stakeholders to ensure any negative impacts on economic development and housing are mitigated to ensure a practical achievement of the state’s climate goals.”

With about one-quarter of the state’s emissions coming from its buildings, Patrick Woodcock, commissioner of the state Department of Energy Resources, estimated that the new building codes would reduce emissions by at least 500,000 tons of carbon dioxide a year in 2030 and save up to $21 billion in construction and operating costs for new buildings.

In an online presentation, Woodcock said new technology and lower fuel costs would save property owners money over the long term. He said it was important for the state to focus first on new construction. He estimated that 27 percent of the buildings that will exist in 2050 haven’t been built yet.

“We need to move forward with integrating the most cost-effective climate solutions into new construction today,” he said.

He added there would be “spillover effects” from the focus on new construction, as it would allow for the training of contractors to perform similar work on existing properties when they are eventually remodeled. It’s unclear if and when the state might require existing buildings to reduce their emissions.

The state’s proposal would update the so-called “stretch” energy code that dates back to the passage of the 2008 Green Communities Act, which provided a range of incentives for communities to require energy efficient development. The vast majority of the state’s towns and cities have adopted the stretch code, so named because it has requirements that extend beyond the state’s base building code.

The proposal would also create a new, more ambitious “specialized” stretch code that aims to have all new buildings either emit no greenhouse gases or have the ability to offset their emissions by producing renewable energy. It would also promote the construction of so-called passive housing, which requires little energy to heat or cool.

Participation in the new stretch code would be voluntary, but state officials said those that take part would be eligible for some $600 million in energy efficiency incentives over the next decade.

The proposed codes provide a legal path for communities to accelerate their efforts to reduce emissions, as some have seen their past efforts stymied. In 2020, for example, Attorney General Maura Healey rejected a bylaw passed by Brookline residents that banned the installation of oil and gas pipes in new and substantially renovated buildings, which would have been the first such prohibition in Massachusetts.

“The proposed changes to the stretch code could be a game-changer for the trajectory of these emissions, and how both residential and commercial new construction happens going forward,” said Cammy Peterson, director of clean energy at the Metropolitan Area Planning Council.

But she worried the proposal was overly reliant on the market.

“Without more stringent performance standards or requirements, builders and owners may still be reluctant to switch away from fossil fuels,” Peterson said.

Kyle Murray, a senior policy advocate at the Acadia Center, an environmental advocacy group in Boston, said he was happy the state’s proposal focuses on reducing emissions in low-rise residential buildings as much as larger commercial buildings.

But he called the decision to allow new buildings to continue to use fossil fuels “puzzling.”

“This represents that opportunity to have a gold standard code in place in the commonwealth,” he said. “I would hate for us to miss that opportunity.”

Read the full article in The Boston Globe here.