The California Energy Commission, in its business meeting on September 9, acted on three related building-code measures that collectively establish new requirements for residential construction across the state. These actions included a formal determination that California’s 2025 Energy Code meets federal standards, the approval of new compliance software, and updates to a critical reference manual. Together, these steps define how builders, designers, and local permitting officials will demonstrate adherence to the upcoming energy efficiency standards.
Specifically, the commission formally determined that the state's 2025 Energy Code for residential buildings meets or exceeds the 2024 International Energy Conservation Code. According to the residential certification materials from the commission, the 2025 Energy Code was adopted in August 2024 and officially took effect on January 1, 2026. Under federal law, California is required to certify its residential provisions by December 30, 2026. The backup packet provided to the commission confirmed that the 2025 Energy Code does indeed meet or exceed the 2024 IECC. An accompanying California Environmental Quality Act (CEQA) memo stated that this certification is not considered a project or, alternatively, qualifies for CEQA’s common-sense exemption, addressing potential environmental review requirements.
In a related action, the commission considered the approval of CBECC 2025.3.0, which serves as the state’s public-domain compliance software for the 2025 Energy Code. Staff materials indicated that this update to the software is designed to align with the newly revised Alternative Calculation Method (ACM) manuals. This updated software is slated to take effect for all permit applications submitted on or after December 18, 2026. The packet also noted that the commission would adopt a CEQA finding, concluding that the software update itself is not a project or is exempt from environmental review.
Finally, staff recommended certifying the updated Alternative Calculation Method Reference Manual for the 2025 Building Energy Efficiency Standards. The materials clarified that this manual update is intended to provide essential support for both public-domain and third-party compliance software tools that are tied to the 2025 Energy Code. As with the other items, staff also recommended adopting a CEQA exemption finding for the manual update.
These three interconnected items—the certified energy code, the approved compliance software, and the updated reference manual—create the comprehensive framework that builders, designers, and permitting officials will use to ensure and demonstrate compliance with California’s 2025 Energy Code. This coordinated approach aims to provide clear guidance and tools for the implementation of the state’s latest energy efficiency requirements.
