Formula & constants
CALGreen 2022 requires multifamily projects of 20+ units to provide 10% EV Capable, 25% EV Ready and 5% EVSE spaces; the 2025 code pushes toward EV-ready receptacles at essentially every space. Nonresidential scoping runs about 20% EV Capable with separate office/retail tables. Each EV Capable space reserves a 208/240V, 40A circuit — which is why a large project can add hundreds of amps of service demand. All default values are editable — when your supplier's data sheet or local code says otherwise, use that number.
Where this fits in your project
This tool is one step in a bigger job. Once you have these numbers, electrical load calculator (Electrical Load Calculator), then conduit fill calculator (Conduit Fill Calculator). For the full sequence see the project workflows, compare approaches on the comparison pages, and check local factors in the state guides.
Frequently asked questions
How many EV charging spaces does CALGreen require?
It depends on occupancy and code year. Under CALGreen 2022, multifamily projects with 20 or more units need 10% EV Capable, 25% EV Ready and 5% EVSE. The 2025 code raises multifamily requirements dramatically, moving toward a Level 2 receptacle at every assigned space.
What is the difference between EV Capable, EV Ready and EVSE?
EV Capable means conduit and reserved panel capacity only — no wire. EV Ready adds the branch circuit and wiring terminating at a receptacle or junction box. EVSE means a working charger is installed and energised on day one.
How much electrical capacity do EV spaces add?
Each Level 2 space reserves 40A at 208/240V, roughly 8.3 kVA. A 100-unit building with full EV-ready parking can add 400–600 amps, often pushing a 2,000A service to 3,000A and changing the transformer and switchgear.
What conduit size is required?
Minimum 1-inch nominal inside diameter under CALGreen, though 2-inch PVC is the practical standard for trenched runs so multiple circuits share a raceway.
Do local codes exceed CALGreen?
Frequently. San Francisco's green building code amends the state tables upward, and several cities have adopted reach codes. Always confirm against local amendments before design.
Last verified: — See our methodology.
Planning estimates only — confirm quantities with suppliers and local code before ordering.