To: Board of Supervisors
From: John Kopchik, Director, Conservation and Development
Report Title: Refer review of the 2025 California Building Standards Code to the Sustainability Committee
☒Recommendation of the County Administrator ☐ Recommendation of Board Committee
RECOMMENDATIONS:
REFER review of the 2025 California Building Standards Code to the Sustainability Committee for consideration and direction, as recommended by the Director of Conservation and Development.
FISCAL IMPACT:
None
BACKGROUND:
In recent decades, the State of California has adopted a new statewide building code every three years. The California Building Standards Commission has now adopted and released the 2025 California Building Standards Code (CBSC), replacing the 2022 CBSC. The CBSC includes the California Building, Residential, Electrical, Plumbing, Mechanical, Wildland-Urban Interface, Green Building Standards, Fire, Energy, Historical Building, and Existing Building Codes. These statewide codes will be effective January 1, 2026. The Department of Conservation and Development is responsible for enforcing the CBSC within the unincorporated area of Contra Costa County.
Local jurisdictions such as the County have the authority to adopt amendments to the Statewide code under conditions specified in State law. As in past code cycles, such amendments must be more restrictive than Statewide code requirements and must be accompanied by findings that the changes and modifications to the statewide code are reasonably necessary because of local climatic, geological, topographical, or environmental conditions.
Recent changes to State law have placed new additional constraints on the authority of local jurisdictions to amend the CBSC as it relates to the construction of new residential housing units. As part of a package of reforms to encourage housing construction in California, Governor Newsom recently signed into law changes to the Health and Safety Code that confine the authority of local jurisdictions to adopt building code amendments related to the construction of new housing to those amendments already in effect as of September 30, 2025, with a few narrow exceptions. This means the County is very restricted in its authority to adopt any new amendments related to new housing construction in the 2025 CBSC. Local jurisdictions retain broader discretion to adopt code amendments related to non-residential construction, subject to making the required findings.
Contra Costa County has a history of adopting a limited number of amendments to the CBSC in past code cycles. In recent years, the Board of Supervisors has adopted code amendments increasing the standards for energy efficiency and the installation of electric vehicle chargers in new residential and commercial construction. Therefore, staff recommend that the Board refer review of the 2025 CBSC to the Sustainability Committee.
CONSEQUENCE OF NEGATIVE ACTION:
If the recommended action is not approved, the Sustainability Committee will not be able to receive information concerning the 2025 CBSC and provide direction to staff concerning adoption of the new building code.