What it costs, what's permitted, and what to ask before you hire.
Last verified: 2026-05-31 · Well-sourced
Panel / electrical
Verify your panel capacity with an electrician
Permit likelihood
Confirm with your building department
Permit snapshot
electrical + building permit
As of 2026-05-31, residential battery energy storage system (ESS) installations in San Francisco are governed jointly by the Department of Building Inspection (DBI) and the San Francisco Fire Department (SFFD) Bureau of Fire Prevention. Per 2022 California Fire Code §105.6.5, a construction permit is required to install an ESS regulated by §1207. Under SFFD Administrative Bulletin 5.12 (Energy Storage Systems in R-3 Occupancies), individual ESS units are limited to 20 kWh, and an aggregate ESS capacity above 20 kWh on a single property typically requires submission of detailed plans to DBI rather than an instant online permit. Eligible installations — existing one- or two-family R-3 homes with no panel upgrade, no ballasted or ground-mounted systems, and compliance with AB 5.12 — may obtain instant electrical permits via SolarAPP+ when paired with a PV system 4 kWdc or smaller, or via DBI's instant online electrical permit pathway for storage 20 kWh or less. Siting rules from AB 5.12 include 3-foot clearance in front of electrical equipment for maintenance, minimum 3-foot separation from the property line for exterior installs (reducible to 12 inches with a 1-hour free-standing fire barrier), and additional fire-rating requirements for attached-garage installs per CFC §1207.11.3 and CRC §R302.6. Existing fire alarm systems may require a separate Fire-Only electrical permit to extend heat detection and notification to the ESS. Verify the current AB 5.12 edition, clearance, and fire-detection requirements with DBI, SFFD, and the installing contractor.