California: reserved breaker spaces in new homes

What the code requires

California adds 408.2(B) to the code. In buildings with one or two dwellings, the panelboard serving each dwelling unit must provide breaker spaces for a heat pump water heater, heat pump space heater, electric cooktop and electric clothes dryer, as specified in Energy Code §150.0(n), (t), (u) and (v). The breakers themselves do not have to be installed.

In practice, the furnace, cooktop and dryer each get one reserved double-pole space in the main service panel. The water heater gets either a single-pole space next to the 120-volt water heater breaker, when the future space is within 3 ft of the water heater, or a double-pole space, when it is more than 3 ft away. Spaces are marked For Future 240V use; the single-pole option is marked Future 240V Use.

Under these electric-ready rules, a new home with a gas furnace, gas cooktop, gas dryer and gas water heater therefore needs three reserved double-pole spaces, plus either a single-pole or a fourth double-pole space for the water heater.

The rest of 408.2 deals with reconditioned equipment: reconditioned panelboards are not permitted, while reconditioned switchboards and switchgear are.

On the job

• Each reserved space must be permanently marked in the panel. An unmarked space does not comply.
• Panel size matters. The Energy Code's battery-ready rule, §150.0(s), also calls for a busbar rated at least 225 A where the service is over 125 A, unless a battery is installed.

Exceptions that matter

• Only required where the matching gas or propane appliance is installed, in new construction, for permit applications filed on or after Jan 1, 2026.

In California

For multifamily buildings, CEC 408.2(C) requires similar spaces but cites Energy Code §160.9(a), (b) and (c), which no longer line up with the 2025 Energy Code's §160.9(b) through (d), so confirm with your building department.

Related sections

• NEC 422.3: California: electric-ready water heater, cooktop, dryer
• NEC 440.3: California: heat-pump-ready circuit at gas furnaces
• NEC 408.4: Panel circuit directory and labeling
• NEC 706.10: California battery-ready rules for new homes

Where this comes from

• California Energy Commission: 2025 Building Energy Efficiency Standards
• California Energy Commission: 2025 Single-Family Residential Compliance Manual, ch. 10
• California Energy Commission: 2022 Single-Family Residential Compliance Manual, ch. 10
• California Energy Commission: 2025 Building Energy Efficiency Standards page
• Read the official NEC free at NFPA