What changed in the 2025 California Electrical Code for ADUs?

The 2025 California Electrical Code took effect on January 1, 2026, and it is based on the 2023 National Electrical Code (NEC), replacing the 2022 edition that was based on the 2020 NEC. For an ADU, the changes you will actually see on your plans are broader GFCI protection, surge protection and emergency disconnect rules for dwellings fed by feeders, a new way to count energy management systems in load calculations, and California amendments that tie your panel to the Energy Code's electric-ready and battery-ready rules.

Which edition applies to your project

The new edition applies to permit applications submitted on or after January 1, 2026. Cities and counties adopt the state code and can file local amendments, so your building department's adopted version is the one your plans must meet. If you applied before that date, ask which edition your plans are being reviewed under.

2023 NEC changes that show up on ADU plans

• GFCI for more appliances. Section 210.8(D) now covers branch circuits for electric ranges, wall-mounted ovens, counter-mounted cooking units, clothes dryers and microwave ovens, alongside items such as dishwashers, whether hardwired or plugged in, for appliances rated 150 volts or less to ground and 60 amps or less. Expect GFCI breakers on the range and dryer circuits.
• Kitchen islands. A receptacle on an island or peninsula is no longer mandatory, but if you leave it out, the code requires provisions at the island for adding one later.
• Surge protection on feeders. Section 215.18 requires a Type 1 or Type 2 surge-protective device where a feeder supplies a dwelling unit, installed in or next to the panel that feeder serves. That reaches the typical ADU subpanel.
• Emergency disconnects. Section 230.85 requires an outdoor emergency disconnect for one- and two-family dwellings with their own service, and new Section 225.41 applies the same idea to dwellings supplied by a feeder, which covers many detached ADUs.
• Energy management systems. Section 220.70 lets the load calculation use the setpoint of an energy management system that limits current, which can help when your main service is tight.
• EV charger load. Section 220.57 counts charging equipment at 7,200 watts or its nameplate rating, whichever is larger.
• AFCI. Section 210.12 covers 120-volt, 10-, 15- and 20-amp circuits serving kitchens, bedrooms, living areas, closets, hallways, laundry areas and similar rooms.

California amendments worth knowing

• Electric-ready circuits. Sections 408.2(B), 422.3 and 440.3 point to Energy Code Section 150.0(n), (t), (u) and (v), which call for breaker spaces and circuits for future heat pump and electric appliances where gas appliances are installed.
• Battery-ready. Section 706.10 points to Energy Code Section 150.0(s) for energy storage readiness and minimum panel busbar ratings.
• EV charging. Section 625.1.1 sends you to CALGreen for new-construction EV rules, and CALGreen Section 4.106.4 Exception 2 exempts ADUs and JADUs that do not add parking facilities.
• Tamper-resistant receptacles. Section 406.12 covers dwelling units, including attached and detached garages and accessory buildings.

What this means for your electrical plan

Your plan set should cite the 2025 California Electrical Code, show GFCI and AFCI protection on the panel schedule, locate the surge-protective device and any required emergency disconnect, and reflect electric-ready or battery-ready items where they are triggered. See our ADU electrical guide and GFCI requirements, compare the energy-side updates in what changed in the 2025 Title 24 energy code, and see how our electrical plans are organized.

Sources: dgs.ca.gov, larimer.gov, mikeholt.com, energy.ca.gov.