2025 California Building Codes

All construction projects submitted on or after January 1, 2026, must be designed per the 2025 California Building Standards Code.

The 2025 California Building Codes including the current Energy Codes are effective as of January 1, 2026. The local ordinance for the Nevada County Land Use and Development Code for local amendments to the code is effective January 1, 2026.

Please refer to handouts and presentations for specific changes to sections of the code.  If you have any questions, please contact the Nevada County Building Department at buildingdept@nevadacountyca.gov or (530) 265-1222 extension 1.

Highlights of Changes in the 2025 Building Standards Code

All of Nevada County is now in seismic design category D.

Snow load data is now provided by the ASCE Hazard Tool. Expect values to increase by approximately 50% for risk category I structures and buildings designed using the CRC an a 100% increase for risk category II structures designed using the CBC.

Backup Power Disconnect Location:
1. The auxiliary energy system disconnect switch shall be installed on the exterior of the main building.
2. Where multiple auxiliary energy system disconnect switches are provided for a single structure, the disconnect switches shall be separated by no more than 3 feet (914 mm).
3. Each auxiliary energy system disconnect switch shall have an approved, permanently mounted, all weather sign indicating the power source it controls. 

Handouts and Links

2025 Residential Code Updates

2025 BOS Presentation

2025 General Notes Sheet

For more information about code updates see the SVABO Resource Library.