2022 CalGreen: New Electrical Panel Pre-Wiring Requirements

The City of Menlo Park has adopted a local amendment to the 2022 California Green Building Standards Code (CalGreen) which will become effective as of March 13, 2025. The amendment adds Section 4.106.5.2 Prewiring requirements here and applies to all:

  • Additions, alterations and repair construction projects which do not meet the definition of “New Construction” as established in the City of Menlo Park Municipal Code Section 12.08.040, to residential buildings(both single-family and multi-family buildings) and/or accessory dwelling unit conversions; and
  • The project includes the replacement or upgrade to the main electric panel. 

Single-family residential buildings and accesory dwelling unit conversions:

The requirements of Section 4.106.5.2 are as follows:

  1. The new main electrical panel must have electrical capacity for and reservation of breaker space in the panel to accommodate the existing single family electrical load and the future electrification of:
    i.  An electric stove and oven if the current stove and/or oven are gas;

    ii.  An electric clothes dryer if the current clothes dryer is gas;
    iii. One Level 2 Electric Vehicle (EV) charger;
    iv. Photovoltaic system (PV) size based on §150.1(c)14 of the 2022 California Energy Code; and

  2. All reserved breaker spaces shall be permanently marked as “For Future EV charging, PV and heat pump water heater use.”

  3. Electrical capacity for and reservation of breaker space in the panel to accommodate a dedicated 240-volt branch circuit for a heat pump water heater. Electrical conductors for the branch circuit shall be installed within three (3) feet from the existing water heater location and shall be rated at 30 amps minimum. Both ends of the unused conductor shall be labeled with the word “spare” and be identified as 240-volt ready.

    Exceptions to requirement number 3:

     Single family and multifamily homes can designate a space at least 2.5 feet by 2.5 feet wide and 7 feet tall with access to hot and cold water suitable for the future installation of a heat pump water heater (HPWH) at location at discretion of building official.

Multi-family residential buildings

The requirements of Section 4.106.5.2 are as follows:

  1. Electrical capacity for and reservation of breaker space in the panel to accommodate a dedicated 240-volt branch circuit for a heat pump water heater. Electrical conductors for the branch circuit shall be installed within three (3) feet from the existing water heater location and shall be rated at 30 amps minimum. Both ends of the unused conductor shall be labeled with the word “spare” and be identified as 240-volt ready.

    Exceptions to the requirement:

    Multifamily buildings as defined in §15.10.030 of the California Building Standards Code where the water heaters are located in each dwelling unit.

The exception is intended to address the possibility that an applicant may want a heat pump water heater to be installed in the future in a different location than the existing gas-fired hot water heater which is why the code language allows for the applicant to identify another suitable location for the water heater when prewiring. 

The proposed ordinance does not impose requirements to use specific appliances, nor does it prohibit the use of gas as an energy source or gas appliances. Additionally, the ordinance does not require the installation of any heat pump based space or water heating equipment, electric vehicle charges or electric stove. The proposed ordinance merely requires expanding a building’s electrical capacity for future electric appliances. 

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