California builds to the highest efficiency standard nationwide
The 2025 California Energy Code, also known as Title 24 went into effect on Jan. 1, 2026, implementing new efficiency standards for buildings and major renovations. Title 24 will make new Californian homes some of the most efficient in the country. Builders can also voluntarily incorporate higher building efficiency standards through a part of the code known as CALGreen, which was also updated with the 2025 Energy Code.
Title 24 will save residents an estimated $4.8 billion in energy costs over the span of 30 years, reduce greenhouse gas emissions by the equivalent of over half a million homes and improve indoor air quality. The code is meant to increase energy efficiency of single-family homes, multifamily housing, both nonresidential and commercial buildings, as well as additions or alterations to existing buildings.
“We are gratified that builders in California will be designing to the 2025 California Energy Code,” said California Energy Commission Building Standards Branch Manager Gypsy Achong. “Compliance with this update is the most affordable way to build a resilient and comfortable building for the future. This update does not mandate specific technologies or fuel types. We continued our long-standing tradition of figuring out what energy budget is pragmatically possible and then asking designers to meet that budget. We are delighted that this approach continues to affordably advance our state’s transition to 100% clean energy in buildings.”
