California 2025 Building Energy Code

In September 2024, California regulators approved the latest edition of its building energy codes. The 2025 Building Energy Efficiency Standards encourage installing heat pumps in new homes and certain nonresidential buildings; replacing old HVAC units with high-efficiency systems in existing commercial buildings; and establishing electric-ready requirements for commercial kitchens and some multifamily buildings. The California Building Standard Commission will review the regulations later in 2024 for final approval.

Commission staff said the new code will save almost $5 billion in energy costs and cut 4 million metric tons of carbon emissions over three years. Much of that would be due to at least 500,000 new heat pumps to heat and cool homes, they estimated. By setting more stringent efficiency standards for new home construction, commission leaders said the new building code serves to encourage installation of heat pumps without an outright mandate to neglect gas appliances. While the new rules fell short of an initially proposed requirement to replace all broken A/C with heat pumps, the rules do allow local governments to incorporate their own heat pump replacement requirements.

The code revisions come as jurisdictions in California — and around the country — grapple with the Ninth Circuit’s rejection of Berkeley, California’s gas ban. As jurisdictions consider alternate means of encouraging building electrification that will not fall prey to federal preemption arguments, California’s new building energy code provides one further nudge in that direction.