Solar Permit Filing in California: SolarAPP+, AB 2188, and What Contractors Get Wrong

Residential solar is the largest permit category for one-and-two-family dwellings in California. The state has spent the last decade pushing cities to make solar permitting faster, first with AB 2188 in 2014 and then with SolarAPP+ adoption mandated under SB 379 starting in 2024. The result for contractors is that most Bay Area solar permits should be approved the same day or the next day. The reason that does not always happen is that the application has to actually meet the checklist, and the checklist is more specific than it used to be.

This is what California residential solar permitting looks like in 2026: when SolarAPP+ is the right path, when AB 2188 is the right path, what the structural and fire-setback rules actually require, and the mistakes that turn a same-day permit into a four-week round trip.

SolarAPP+ Is the Default Path Now

SolarAPP+ is a free automated permitting platform built by the National Renewable Energy Laboratory and adopted by California cities under SB 379. The contractor uploads the system design, the platform runs an automated code compliance check against the California Building Code, the California Residential Code, and CEC Article 690, and if the design passes, a permit is issued in minutes. The city receives the file and the contractor pays the fee through the city's portal.

As of 2026, more than 200 California jurisdictions accept SolarAPP+ submissions, including most of the Bay Area: San Jose, Oakland, Sunnyvale, Hayward, Fremont, Berkeley, Richmond, Concord, Walnut Creek, and most peninsula cities. San Francisco DBI does not currently accept SolarAPP+. Cities that adopted SolarAPP+ are required by SB 379 to keep it as an option even if they also offer a regular review path. The fee for a SolarAPP+-issued permit is usually lower than the AB 2188 cap because the city's actual processing cost is near zero.

The catch is that SolarAPP+ has a specific scope: rooftop PV up to 38.4 kWdc on a single-family or duplex dwelling, with a microinverter or string inverter topology that the platform recognizes, no battery, no main service panel upgrade. Anything outside that scope falls back to the regular review path. Battery-coupled systems are common enough that we cover the storage side separately in our piece on battery storage permit requirements.

AB 2188 Is the Fallback, and It Is a Strong One

When the design does not qualify for SolarAPP+, the project falls back to the expedited solar permit process under AB 2188 (Government Code section 65850.5). The law requires every California city and county to adopt a checklist-based, ministerial review process for residential solar. The practical consequences are that the permit has to be issued within three business days for systems up to 10 kW and within five business days for larger systems. Discretionary review is prohibited. The fee is capped at $450 for systems up to 15 kW and $500 for systems above 15 kW. Cities cannot require structural calculations beyond what the checklist requires.

San Francisco DBI is the city that historically pushed back hardest on AB 2188. Enforcement actions and contractor complaints have brought them more in line, but SF still routes solar applications through their general intake instead of giving them a dedicated track, which makes the practical timeline longer than the statutory one. We covered the same dynamic for SF on the HVAC side in filing an HVAC permit in San Francisco.

What the Application Actually Has to Show

The AB 2188 checklist and the SolarAPP+ input form converge on the same items. The site plan shows the array footprint, fire setbacks, and the property lines. The roof plan shows the module layout, the inverter location, the rapid shutdown initiator, and the conduit run to the main service panel. The one-line diagram shows the module strings or microinverter groups, the inverter, the AC disconnect, the backfeed breaker or supply-side connection, and the main service rating. The structural data sheet shows the rafter size and spacing, the attachment spacing, and the manufacturer's installation manual reference for the racking system.

The structural data sheet is where most rejections start. Cities accept the racking manufacturer's engineering letter (IronRidge, Unirac, SnapNrack, Pegasus all publish California-stamped letters) for typical installations, but the attachment spacing in the field has to match the spacing the letter references. If the letter says 48 inches on center and the layout shows 72 inches because of obstructions, you need a project-specific structural calc, not the generic letter.

CRC R324 Fire Setbacks Are Not Negotiable

California Residential Code section R324 (formerly section 1505 of the older code) governs rooftop solar fire setbacks. The rules: a 3-foot setback from the ridge along ridges that border another roof plane, a 3-foot setback from valleys, an 18-inch setback from hips, and a clear pathway from the eave to the ridge on each roof plane that bears panels. The pathway has to be 36 inches wide on roofs with two pathways and 18 inches wide on dwellings that qualify for the smaller-pathway exception (single-story or roof slope under 2:12).

The setbacks are exactly what fire departments check during plan review. Designs that maximize panel count by encroaching into setbacks get rejected. The fix is to design to the setbacks first and let the production model fall out, not the other way around. The same logic applies to wildland-urban interface (WUI) fire zones, where additional CFC chapter 12 requirements apply.

NEM 3.0 Made the Permit-Plus-Interconnection Workflow More Important

Under NEM 3.0, the export rate is low enough that most residential solar projects pencil only when paired with battery storage. The implication for permitting is that the city permit and the PG&E interconnection application have to be filed in sync, and the one-line diagrams have to match. Mismatches between what the city approved and what PG&E approved are the single most common cause of delayed permission to operate.

The order is design freeze, simultaneous SolarAPP+ or city permit submission and PG&E interconnection submission, install, building inspection, PG&E inspection, PTO. Skipping the simultaneous filing adds four to eight weeks to the timeline, which on a 9 kW + battery project is roughly $2,000 to $3,000 of carrying cost.

Permit Fees Across Bay Area Cities

Because AB 2188 caps fees, the spread across cities is small. San Jose, Oakland, Sunnyvale, Santa Clara, Fremont, Hayward, and most peninsula cities sit at or just under the $450 cap for systems up to 15 kW. Berkeley and Richmond are in the same range. San Francisco DBI charges to the cap and historically pushed beyond it on systems they routed through plan review. SolarAPP+ jurisdictions sometimes charge $200 to $350 because the automated path is cheaper for them to process. Adding a battery is a separate permit on a separate fee schedule, and adding a panel upgrade is a third permit again.

The Most Common Solar Permit Mistakes

Submitting through SolarAPP+ when the project includes a battery or a panel upgrade, then wondering why the platform rejected it. Encroaching into R324 fire setbacks to add a few extra modules. Submitting a generic structural letter when the field attachment spacing does not match the letter's spacing. Filing the city permit and the PG&E interconnection out of sync. Forgetting the rapid shutdown initiator and labeling on the one-line. Filing in San Francisco the same way you file in San Jose, when SF requires a different intake entirely. Not pulling the WUI status before designing the roof layout. Same family of issues we cover in 7 permit filing mistakes that cost contractors weeks of delays, just on the solar side.