LADBS SolarApp+ Guide — Step-by-Step Solar Permit Submission for LA Installers

Los Angeles is the largest single solar permit market in the United States. The LA Department of Building and Safety (LADBS) processes more residential solar permits than any other municipal building department in the country — and since adopting SolarApp+ as its primary residential solar permit pathway, LADBS has transformed from one of the slower California AHJs into one of the fastest for qualifying systems.

This guide gives solar installers and permit designers a complete operational walkthrough of the LADBS SolarApp+ process: eligibility screening, step-by-step submission, common disqualifiers, permit issuance mechanics, and what to do when a system falls outside SolarApp+ eligibility and requires a manual LADBS plan check.

Direct answer. LADBS processes residential solar permits ≤ 25 kW AC through SolarApp+ with permit issuance typically in 1–3 business days. Systems must use a UL 1741-listed utility-interactive inverter on a wood-frame residential roof with standard rafter spacing. SolarApp+ does not handle storage co-permits, supply-side interconnection, or systems with non-standard structural conditions. Manual LADBS plan check typically takes 5–15 business days for residential and 15–45 days for commercial.

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LADBS Jurisdiction — City of Los Angeles Boundaries

LADBS covers properties within the City of Los Angeles boundaries. This distinction is critical:

Jurisdiction	Building Department
City of Los Angeles (LADBS)	LADBS — processes SolarApp+
Unincorporated LA County	LACPW (LA County Public Works)
Long Beach	City of Long Beach Building and Safety
Pasadena	City of Pasadena Building and Safety
Santa Monica	City of Santa Monica Building and Safety
Torrance, Burbank, Glendale, etc.	Each city has its own building department

For the broader California AHJ landscape, see the California AHJ Solar Permit Guide.

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SolarApp+ Eligibility — The 8-Point Screening Checklist

Before starting a SolarApp+ submission for an LADBS project, run through this eligibility checklist. A single disqualifying condition means the project needs a manual LADBS plan check.

1. Occupancy: Residential (R-3 single-family dwelling or R-2 multi-family up to 3 stories). Commercial systems are not eligible.
2. System size: ≤ 25 kW AC total inverter output. This is AC output capacity, not DC array wattage.
3. Inverter type: Utility-interactive inverter with UL 1741 listing. Inverter must be on the CEC-approved inverter list (California Energy Commission list, separate from MNRE). Microinverters and string inverters are both eligible if UL 1741 listed.
4. Roof structure: Wood-framed roof with rafter spacing ≤ 24 inches on-center. Concrete tile, clay tile, and composition shingle are all acceptable roof materials. Metal standing seam and flat roofs: check current SolarApp+ eligibility — some are supported with specific attachment products.
5. Racking system: Must use an attachment and racking product from SolarApp+‘s pre-approved product library. If the racking product is not in the SolarApp+ library, the system is not eligible.
6. Interconnection method: Load-side interconnection using the 120% busbar rule (CEC 705.12(D)(3)). Supply-side interconnection (line-side tap) is not eligible for SolarApp+.
7. No battery storage: Battery storage in the same permit application disqualifies from SolarApp+. Storage requires a separate manual LADBS permit or a separate co-permit application.
8. No service panel upgrade: If the project includes an electric service panel upgrade, the solar permit must be filed separately. Panel upgrade and solar cannot be combined in a SolarApp+ submission.

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Step-by-Step LADBS SolarApp+ Submission

Step 1 — Create or Log In to SolarApp+ Account

Go to app.solarapp.org (the national SolarApp+ platform, not an LADBS-specific URL). Create a contractor account if this is your first use. You will need:

• Business license number
• Contractor license number (C10 electrical or C46 solar specialty)
• Business contact email and phone

LADBS requires that the SolarApp+ submission be made by a C10 or C46 licensed contractor. The property owner can initiate an account but the permit must be associated with a licensed contractor.

Step 2 — Enter Project Address and Confirm LADBS Jurisdiction

Enter the project address. SolarApp+ auto-identifies the AHJ based on the address. Confirm LADBS appears as the AHJ — if another jurisdiction appears, the address is outside LADBS boundaries.

Step 3 — Enter System Parameters

SolarApp+ guides you through a structured questionnaire:

• Module make, model, and quantity (module must be in SolarApp+‘s module database)
• Inverter make, model, and quantity (must be in SolarApp+‘s inverter database and UL 1741 listed)
• Racking make, model (must be in SolarApp+‘s product library)
• Roof type and pitch
• Rafter size, spacing, and span (for structural prescriptive pathway)
• Service panel ampacity and main breaker size
• Existing solar, EV chargers, or other loads on the busbar

Step 4 — SolarApp+ Automated Eligibility Assessment

SolarApp+ runs automated checks including:

• 120% busbar rule calculation (sum of all source OCPDs ≤ 120% × busbar ampacity)
• CEC 690.12 rapid shutdown compatibility
• Fire setback compliance check (based on roof dimensions and array placement inputs)
• Structural prescriptive pathway check (rafter sizing vs. span vs. racking point loads)

If the automated check fails, SolarApp+ will indicate which parameter is disqualifying. Some failures are correctable by adjusting system design (e.g., reducing array size to stay within busbar limit); others require a manual permit.

Step 5 — Generate and Review the Permit Package

If the automated assessment passes, SolarApp+ generates a permit package including:

• Project-specific single-line diagram
• Roof plan with fire setback annotations
• Structural prescriptive analysis
• Equipment cut sheets
• Compliance checklist

Review the generated package before submission. The most common generation error is a busbar calculation that does not account for the customer’s existing subpanels or other generation sources on the same busbar.

Step 6 — Submit to LADBS and Pay Fees

SolarApp+ submits the permit package directly to LADBS’s permit system. LADBS reviews the submission electronically. Current LADBS solar permit fees for residential systems:

• Base permit fee: approximately $150–$350 depending on system size
• Plan check fee: typically included in the SolarApp+ rapid approval fee
• State surcharge: additional ~$35–$50

Fees are paid online at the time of submission.

Step 7 — Permit Issuance

LADBS typically issues SolarApp+ permits within 1–3 business days. The permit is issued electronically. Download the PDF permit and all required inspection cards.

Step 8 — Installation and Inspection

Install per the issued permit documents. Schedule LADBS inspection through the LADBS permit portal or by calling the LADBS inspection hotline. LADBS typically provides inspection within 2–5 business days of scheduling. The inspector will verify the installation matches the approved permit documents.

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Common SolarApp+ Disqualifications — And Fixes

Disqualification	Why It Happens	Fix
Module not in SolarApp+ database	Newer model not yet added	Use a listed module or submit manually
Racking not in SolarApp+ library	Proprietary or newer racking	Use a listed racking system or submit manually
Busbar calculation fails 120% rule	Undersized panel for system size	Reduce system size, or plan a panel upgrade before the solar permit (separate permit)
Rafter spacing > 24”	Older home with wide rafter bays	Requires structural engineering — manual permit
System > 25 kW AC	Oversized for SolarApp+	Manual permit; consider whether design can be split
Supply-side interconnection selected	Design uses line-side tap	Change to load-side if panel allows; or manual permit
Battery storage included	Co-permit with storage	Separate the storage into a separate manual permit

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Manual LADBS Plan Check — When SolarApp+ Is Not an Option

For systems that do not qualify for SolarApp+, LADBS accepts manual plan check submissions through its ePlans (ProjectDox) online portal.

Manual LADBS plan check requirements:

• Complete permit application form
• Site plan, electrical plan (SLD), roof plan, structural calculations
• Equipment cut sheets and specifications
• For commercial systems: 3-line diagram, load schedule, utility coordination letter

Manual LADBS timelines:

• Residential (standard): 5–15 business days for initial plan check review
• Commercial (< 100 kW): 10–21 business days
• Commercial (> 100 kW): 21–45 business days

LADBS uses a round-based plan check system — corrections (if any) are issued as a list, and the applicant responds with a revised submittal. Each correction round adds approximately 5–10 business days.

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Stats: LADBS vs. Other LA Area AHJs

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How Heaven Designs Helps LA-Area Installers

The two common failure modes for LA installers — SolarApp+ disqualifications not caught before submission, and manual plan check correction rounds on non-standard systems — are both preventable with the right engineering support.

• Solar Permit Design (USA) — LADBS-specific permit packages: SolarApp+-qualified packages delivered in 2–3 business days; manual LADBS packages in 4–7 business days. Pre-submission eligibility screening included. 96.2% first-pass approval rate.
• Solar 3D Pre-Design — 48-hour sales-stage layout with California Fire Code setback annotation and busbar calculation — catches SolarApp+ eligibility issues before design lock.
• Download sample deliverables — Sample includes an LADBS-format residential permit set.

For the full California AHJ landscape, see California AHJ Solar Permit Guide.

Glossary: AHJ, SolarApp+, rapid shutdown, NEC 705.

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FAQ

Does LADBS accept SolarApp+ permits for multi-family solar?

LADBS SolarApp+ eligibility extends to R-2 multi-family residential up to 3 stories under specific conditions. The system must still meet the ≤ 25 kW AC limit per building permit (a multi-family building with multiple permits may have multiple SolarApp+ submissions). Larger multi-family systems requiring a single permit > 25 kW need manual plan check.

What is the LADBS C10 vs. C46 contractor requirement for SolarApp+?

LADBS requires that solar installations be performed by a C10 (Electrical) or C46 (Solar Contractor) licensed contractor. The SolarApp+ submission must be associated with a valid C10 or C46 license. Homeowners submitting their own permits (owner-builder) must confirm LADBS’s current owner-builder solar permit policy — requirements have varied.

Can I add battery storage to a SolarApp+-approved solar permit?

No. Battery storage cannot be included in a SolarApp+ solar permit application. Storage requires a separate manual LADBS permit under CEC 706 and NFPA 855. Apply for the solar permit via SolarApp+ and the storage permit via manual LADBS ePlans as separate applications. Both must be inspected — the storage inspection is independent of the solar inspection.

How does LADBS handle solar for ADUs (Accessory Dwelling Units)?

ADU solar installations in Los Angeles must meet Title 24 requirements for new ADU construction. The permit goes through the same LADBS pathway (SolarApp+ if eligible, manual if not). For attached ADUs, the solar system may share the existing main panel; for detached ADUs with their own service entrance, a separate solar permit is required.

What is the most common plan correction on LADBS manual plan checks?

Based on Heaven Designs’ LADBS submission history, the most common corrections are: (1) fire setback annotations missing or incorrect on the roof plan (California Fire Code 605.11 is the top correction item nationally); (2) busbar calculation showing the 120% rule for load-side interconnection not accounted for correctly when the home has other generation sources or sub-panels; and (3) rapid shutdown labeling non-compliant with CEC 690.56 — the label must specifically reference the initiation device at the utility-interconnected service entrance.