The California Energy Commission is looking harder at decarbonizing buildings by reducing carbon “embodied” in construction materials, such as concrete and steel, during the manufacturing process.

The commission has been aware of the environmental harm from embodied carbon for some time, but stakeholders have pressed the CEC to get more involved as part of its role in drafting the state building code, Commissioner Andrew McAllister said at a workshop Thursday.

“This is a global issue, not just California, and there are very smart people thinking about this across the globe,” McAllister said.

Proponents say it is time California joined the ranks of European nations such as Denmark in weeding out carbon from building materials.

So far, the CEC has focused primarily on electrification and energy efficiency to decarbonize buildings but has not “looked at all at the impacts of embodied emissions, which is to say the energy consumed, the environmental damage created, by making the physical building materials, equipment and other pieces of our built environment,” Rebecca Dell, industry program director at the San Francisco nonprofit ClimateWorks Foundation, told workshop participants.

“This is an opportunity for the California Energy Commission to double the impact of its building energy codes,” Dell said.

She likened it to California’s “profligate use of energy” before it began regulating appliance energy efficiency decades ago, a relatively low-cost solution that yielded large energy savings.

The state’s efforts to increase efficiency slowed energy demand, even as its population grew, so that it now has one of the lowest per capita consumption rates of any state, the U.S. Energy Information Administration says.

“Managing for embodied emissions” could reduce waste and cut greenhouse gasses at a relatively low cost, too, Dell contended.

That would mean, for example, eliminating carbon from cement manufacturing. Cement is a primary component of concrete, the world’s most common building material.

There are still eight coal-burning cement kilns in California that produce inordinate amounts of pollution, she said. The plants are primarily in the Mojave Desert and the Central Valley, near lower-income communities.

“These are the only facilities left in California that still burn coal as their primary source of fuel,” Dell said.

The International Energy Agency estimated in 2019 that about 11% of global carbon dioxide emissions come from manufacturing steel, cement and other building materials, as well as on-site building construction.

In California, cement production accounted for 1.8% of GHG emissions in 2017, according to the California Air Resources Board.

California has begun addressing embodied carbon through its Buy Clean California Act, which requires the state Department of General Services to establish and publish the maximum acceptable “global warming potential” for certain construction materials such as structural steel, flat glass and mineral wool board insulation. Senate Bill 778, by state Sen. Josh Becker (D) of San Mateo, would add concrete to the list.

Other states, including Colorado, are pursuing similar courses of action.

The building industry, however, says it may be tougher than environmental advocates suggest to decarbonize cement and concrete because of the difficulty of replacing coal as a fuel source and other manufacturing issues. (See Challenges Loom for Decarbonizing Concrete and Calif. Bills Seek to Decarbonize Concrete.)

Dell said it’s essential to reduce embodied carbon in building materials in California, with its ambitious GHG reduction goals, because clean energy, energy efficiency and building decarbonization through electrification of major appliances is already underway.

Moreover, California has a relatively mild climate that doesn’t require as much energy for heating and cooling as other parts of the world, necessitating GHG reductions in other areas, she said.

“We have a relatively clean electricity grid, so one unit of electricity is associated with fewer greenhouse gas emissions than in most places,” Dell said. “And we already have quite an energy efficient stock of buildings compared to a lot of places.”

“All of those things are driving down our operational energy and greenhouse gas emissions, which means that the embodied emissions are even more important here in California than in other in other places, so you have an opportunity, as I said, to double your impact,” she told CEC commissioners and staff.