LA County solar permits: express permits, fire rules and the corrections plan checkers send back

Who this guide covers

This guide is for the unincorporated areas of Los Angeles County, where LA County Public Works, Building & Safety is the permitting office and LA County Fire is the fire authority. Cities inside the county that run their own building departments — Los Angeles, Long Beach and many others — have their own rules, so confirm which department issues permits for the address before you start.

LA County at a glance

Item	Unincorporated LA County
Where to apply	EPIC-LA (Public Works online portal)
Codes	2026 County Building, Electrical and Residential codes (Titles 26, 27, 30), based on the 2025 California codes, effective Jan 1, 2026
Instant permits	Self-issued “Express Solar Roof Mount Residential” and “…with ESS” permits for qualifying jobs (the county’s own platform, not SolarAPP+)
Over-the-counter review	PV up to 10 kW, batteries under 20 kWh
Batteries	LA County Fire approval and inspection; not inside the dwelling; 20 kWh per unit; up to 80 kWh in garages and 160 kWh outside
Disconnects	Within 6 ft of the main panel, on the same wall, each with a numbered LA County Fire placard (“#X of Y”)
First page of the plans	LA County Fire’s code note and an ESS scope of work, written as the guide specifies
Structural calcs	Required unless the job meets the county’s light-load criteria (below)
Inspections	Requested in EPIC-LA, in person or virtual; LA County Fire inspects batteries
Utility	SCE for most of the county — confirm by address

Express permits and plan check

Through EPIC-LA, a contractor can self-issue an express permit for a residential rooftop system that meets the county’s eligibility list, with or without a battery. The county’s contractor affidavit for small rooftop systems covers systems up to 38.4 kW AC. Jobs that don’t meet the list go to plan check; a battery on its own is an Electrical (Complex) permit. The county also asks for proof that the roof structure itself is permitted.

What the county’s plan review list asks for

The county publishes a solar PV plan review list. A set that answers it in full avoids most first-round comments:

• Roof plan on the site plan, with the roof covering class, number of layers and slope
• Anchor and flashing details, with the added dead load noted
• Single-line diagram with conductor derating, and module and inverter data
• Grounding, or a racking system listed to UL 2703
• The NEC 705.12(B)(3) busbar check, rapid shutdown, and the label schedule
• For batteries: UL 9540 listing, an exterior disconnect on one- and two-family homes, and the power control system’s listing and settings where one is used

LA County Fire: batteries and disconnects

LA County Fire leaves rooftop PV review on one- and two-family homes to Building & Safety, but not batteries. Battery systems over 3 kWh need LA County Fire approval and an inspection before they’re used. Its rules are in the ESS & PV Requirement Guide for R-3/R-4 Occupancies (EG-10, revised September 4, 2024), and they’re stricter than the state code.

The guide recognizes three routes. Jobs on the county’s express permit need no plans for Fire either. On the Fire Fast-Track route, Building & Safety reviews plans and Fire doesn’t. A battery inside an attached garage can’t use Fast-Track: unless the job is on an express permit, plans go to LA County Fire because of the fire-detection requirements.

Rule	LA County Fire requirement
Where batteries may go	Detached garages; attached garages only with the required fire separation from the living space; outdoors or on exterior walls
Where they may not go	Inside the dwelling or an ADU, sleeping rooms or spaces opening into them, closets, bathrooms, basements, accessory buildings that aren’t garages, vaults
Size	20 kWh per unit at nameplate capacity, not usable. Fire’s interpretation: up to 80 kWh in total in garages, up to 160 kWh in total on exterior walls and outdoors, 240 kWh per property
Spacing between units	3 ft in any direction, measured along the wall surfaces (no measuring through a wall), including units on opposite or adjacent walls
What counts as one “unit”	A group of UL 9540-listed units totaling no more than 20 kWh counts as one unit, but only where the manufacturer’s listed instructions allow them closer than 3 ft. No mixing of makes or models unless the instructions allow it
Outdoor clearances	5 ft from lot lines, public ways, other buildings, stored combustibles and hazardous materials; 10 ft from vegetation; 3 ft from doors, windows, operable openings, HVAC inlets and vents into the home (crawl-space vents and exhaust vents count), and from the gas meter regulator
Closer to the lot line	A wall-mounted unit no more than 18 in deep may sit inside the 5 ft setback if any fence or wall within 5 ft has a noncombustible, nonmetallic surface extending 5 ft past each side of the unit (the guide’s Appendix F)
Disconnects	Within 6 ft of the main panel, on the same wall plane, not separated by walls, gates, fences, vegetation or architectural features; reachable from the ground without a ladder
Batteries in a garage	A remote disconnect device outside, within 6 ft of the main panel, that disconnects at the battery itself
Attached garages	Heat detection with a notification device in the home: a listed heat detector on a fire alarm system, or a sprinkler with a flow switch. Devices must be intermediate-rated; no heat alarm is currently approved for garages
Vehicle impact	Impact protection where a car could reach the unit, unless the whole unit is 36 in or more above the floor

Disconnect placards and the disconnect schedule

LA County Fire has its own placarding system, and it’s where many sets get sent back. Every switch a firefighter must operate to cut all power to the house gets a numbered placard reading “F.D. – ELECTRICAL BLDG DISCONNECT # X of Y”:

• What counts: the utility service is always #1. Every PV system, battery and pre-wired generator input adds a number, and so does each rapid-shutdown initiator, new or existing.
• Exterior placards: at least 2 in × 3.5 in, weather-resistant engraved plastic, red letters on yellow, Arial capitals at 24 pt with “F.D.” and “# X of Y” in bold at 28 pt, fixed with epoxy.
• Inside a panel: where several breakers in one panel must be switched off, each gets a small placard (at least 7/16 in × 3/4 in) with its number.

Plans submitted to Fire need an electrical power source disconnect schedule on the garage floor plan or the partial floor plan. It lists each source with its placard number and the device that disconnects it. The guide’s own example:

Energy source	Placard	Disconnecting device
Utility service	1 of 5	200 A main breaker
ESS	2 of 5	30 A blade disconnect
New solar PV	3 of 5	30 A blade disconnect
Existing solar PV	4 of 5	Emergency stop button
Generator (input)	5 of 5	Transfer switch

What goes on the first page

LA County Fire wants these on page 1 or 2 of the plans, written exactly as its guide gives them:

• The code note: “All work shall be in compliance with the most current Los Angeles County Fire Code (LACFC).”
• An ESS scope of work covering new and existing batteries: the number and type or chemistry of the units, the nominal kWh of each model, the total kWh for the site, where each unit is installed, and the minimum number of disconnects needed to cut every power source to the house.

On our LA County sets we also add two notes that reviewers look for: that the project complies with the current LA County Fire Department Electrical Power Source Disconnect Placarding System, and, where a battery goes in a garage, that the attached garage complies with all applicable codes, standards and the manufacturer’s listed installation manuals, including fire-protective features such as gypsum board, doors and ducts, and alarm or detector devices.

Plans submitted to Fire also need minimum drawing scales (site plans 3/32″ = 1′-0″, floor plans 3/16″, garage plans and wall elevations 1/4″), and dimensions from every battery to any door, window, opening, corner, lot line or other unit within 7 ft of it.

Structural: when calculations are needed

Stamped structural calculations by an architect or civil engineer are required unless every one of these holds: the roof has no more than two layers of wood, asphalt shingle or rolled roofing; the system adds no more than 4 psf; no point load exceeds 40 lb; the array sits no more than 18 inches above the roof; and supports are no more than 48 inches apart, fastened with 5/16-inch lags embedded at least 2.5 inches. Tile, a third layer, wider attachment spacing or a heavier system means calculations. See when you actually need a structural stamp.

What plan checkers flag here

These are the corrections plan checkers send back most often — here and in most jurisdictions — with what LA County specifically expects, and how to answer each one on the sheet before it’s asked.

1. The busbar 120% rule. The county’s list asks for the 705.12(B)(3) check, and it’s the most common correction everywhere. Show the math on the line diagram — and remember that an AC-coupled battery adds to the backfeed. If a power control system limits it, show the PCS listing and the current setting. Check it in the busbar 120% calculator.
2. Wire size for the breaker. The same breaker gets different wire sizes from different reviewers. See the section below — a 75 °C termination note and conductors sized to the protective device prevent most of these.
3. Disconnect locations. LA County Fire wants the disconnects within 6 ft of the main panel, on the same wall, with nothing between them — no corner, gate, fence or landscaping. Dimension it on the site plan and the equipment elevation, and number every placard to match the disconnect schedule.
4. Fire setbacks and roof access. Show the pathways and the ridge setback with dimensions, and mark at least two roof access points. See fire access pathways and setbacks.
5. Attachment spacing. Over 48 inches on center takes the job out of the county’s no-calculation criteria, so expect a request for a structural stamp.
6. Voltage drop. Large PV-with-battery systems with long runs get asked for the calculation. Run it in the voltage drop calculator and put the result on the line diagram.
7. Equipment that matches the utility application. The model numbers on the plans should match the SCE interconnection application exactly — modules, inverters and batteries.
8. Current specification sheets. Include sheets showing the listings: UL 1741 for inverters, UL 9540 for batteries, and UL 2703 with the fire classification for the racking.
9. An equipment elevation sheet. With a battery, reviewers want to see the wall: where each piece of equipment is mounted, the 3 ft clearance from doors, windows and vents into the home, and the disconnects within 6 ft of the main panel.

Where LA County is strictest. In our experience, three things come back on LA County battery jobs more than anywhere else: disconnects that aren’t right next to the main panel, placards that don’t state how many disconnects there are and which is which, and a missing or incomplete ESS scope of work on the first page. Each is covered in the LA County Fire section above.

Why the same wire gets accepted in one city and rejected in the next

Most wire-size corrections come from three code rules that reviewers apply differently:

• 60 °C or 75 °C terminations (NEC 110.14(C)(1)(a)). For circuits of 100 A or less the code assumes 60 °C terminations unless the equipment is listed for 75 °C. That's the whole difference between #4 and #3 on an 80 A breaker, or #2 and #1 on a 100 A sub panel.
• The 83% dwelling rule (NEC 310.12). Service conductors, and the feeder carrying the whole house, may be sized at 83% of the rating: #2/0 copper for 200 A. A feeder to a backup loads panel doesn’t carry the whole house, so the rule doesn’t apply, and 200 A protection needs #3/0 copper.
• The breaker sizes the wire (NEC 240.4). A 200 A-rated backup panel fed through a 100 A breaker needs wire for 100 A, not 200 A.

Breaker	Copper, 60 °C terminations	Copper, 75 °C terminations
70 A	#4	#4
80 A	#3	#4
90 A	#2	#3
100 A	#1	#3
200 A, whole-house feeder	#2/0 (83% rule)
200 A, other feeders	#3/0

A note on the line diagram stating that terminations are rated 75 °C, backed by the equipment’s specification sheets, answers the first rule before it comes up.

Inspections

Inspections are requested in EPIC-LA and can be in person or virtual. The first is due within 12 months of the permit being issued, and then at least every 180 days. LA County Fire inspects battery systems separately.

Utility interconnection: SCE

Most of the unincorporated county is SCE territory — confirm by address. SCE takes interconnection applications through PowerClerk under its net billing tariff, with single-line diagram templates for systems under 30 kW. Line-side taps are discouraged and never allowed in sealed sections; SCE considers them case by case with a PE-stamped single-line diagram.

Sources

Checked October 2026 against LA County Public Works Building & Safety (codes, the 2026 solar PV plan review list, EPIC-LA guides and the small rooftop solar affidavit), LA County Fire’s “ESS & PV Requirement Guide for R-3/R-4 Occupancies” (EG-10, revised September 4, 2024) with its appendices on impact protection, disconnect placarding, openings, unit grouping, detection and lot-line setbacks, and SCE’s interconnection documents. Requirements change; confirm the current version with the county before you submit.

We draw LA County sets to these requirements — the busbar check, the disconnect distances and the battery clearances shown on the sheet. Start a work order, or plan the system first in the free solar line diagram builder.