Minimum Plan Submittal Requirements for ADU/JADU (LA County Building & Safety)

The LA County ADU Plan Submittal Checklist: What "Complete" Actually Means If you're building an ADU in unincorporated Los Angeles County, the single bigges...

Written by 1-800-ADU-Pros

Last updated: July 16, 2026•8 min read

Minimum Plan Submittal Requirements for ADU/JADU (LA County Building & Safety)

The LA County ADU Plan Submittal Checklist: What "Complete" Actually Means

If you're building an ADU in unincorporated Los Angeles County, the single biggest reason projects stall isn't the design or the money — it's an incomplete plan set. LA County Building & Safety (BSD) publishes a one-page handout called the "Minimum Plan Submittal Requirements — Accessory Dwelling Unit," and it's the closest thing to a cheat sheet you'll find. Hit every item on it and your plans get accepted. Miss one and you're stuck in correction cycles that add weeks.

Here's the plain-English version of what your drawings need to contain.

First, a jurisdiction reality check

This checklist is a County document, and it only applies to unincorporated LA County. If your home is inside a city — including the City of Los Angeles — you file with that city's department instead. Confirm your jurisdiction on the County's service locator before doing anything else.

What a "complete" ADU plan set includes

BSD groups the minimum requirements into four buckets. Think of these as the sheets your architect or designer must produce.

Site plan and general notes

A scaled site plan showing lot size, property lines and dimensions, adjacent streets, setbacks, other structures, easements, a north arrow, and drainage pattern. Plus general notes listing the applicable codes, occupancy classification, type of construction, scope of work, and existing vs. proposed building area.

Architectural sheets

Floor plans that clearly label existing vs. new construction, with door/window locations and schedules.
A roof plan with drainage, roofing material and slopes, ridges/valleys, eave overhangs, and attic vents.
Exterior elevations showing wall finishes, building heights, openings, and finish grade lines.
Cross sections (full height and width) showing framing, foundation, and insulation in two directions.
Door, window, and finish schedules.

Structural sheets

A foundation plan with footing locations, anchor-bolt and hold-down schedules, and details.
A framing plan covering joist/rafter/beam sizes, spacing, and spans — plus all lateral elements, including a shear-wall schedule.
Structural calculations if your design deviates from the conventional Residential Code. These must be wet-stamped and signed by a California-licensed engineer or architect.

Energy, green, and the rest

A Title 24 energy Certificate of Compliance (CF1R).
CALGreen notes, mechanical (HVAC) equipment and specs, and electrical details including smoke/CO detector and exhaust-fan locations.
Fire hazard zone details per Code Section R337 where applicable.
Solar PV for new detached ADUs — required, and the solar-ready zone must appear on the roof plan.

How to file

Get Department of Regional Planning approval first (a Ministerial Site Plan Review, roughly 60 days). Then submit your plan set to BSD one of two ways: upload everything as a single combined PDF through the EPIC-LA portal, or drop off two 24-inch by 36-inch paper sets at a County district office. Once BSD accepts the submittal it invoices plan-check fees — and your review clock only starts ticking after those fees are paid.

After review, you'll get an Agency Referral sheet listing additional clearances (Fire, Public Health, sewer/septic). The permit can't be issued until every one of those is cleared. Then pay the permit fee and pull your permit — within one year of the application date.

What it costs and how long it takes

The checklist is free. Expect to pay Planning's Site Plan Review fee (around $1,000 — confirm the current amount), valuation-based BSD plan-check and permit fees, and separate agency clearance fees. There's no flat ADU permit price; it scales with project valuation. Want to skip most of this? The County offers free pre-approved ADU Standard Plans (A, B, and C) that already satisfy these requirements — they just can't be modified.

The mistakes that cost people weeks

Submitting to BSD before Planning approval.
Filing with the County when the property is actually inside a city.
Missing the Title 24 CF1R or leaving energy values off the plans.
Forgetting solar PV on a new detached ADU.
Unstamped structural calcs.
Plans that don't separate existing from new work, or omit the shear-wall schedule.
Uploading multiple PDFs instead of one combined file, or bringing a single paper set.

Treat the Minimum Plan Submittal Requirements as your pre-flight checklist. Walk it line by line with your designer before you hit submit, and you'll skip the most expensive delay in the entire ADU process.

Sources: LA County Public Works Building & Safety — Minimum Plan Submittal Requirements for ADUs, Expedited ADU Checklist V4.2, ADU Step-by-Step Guide, and the County Pre-Approved ADU Standard Plans program.

Reference card

Official number: No IB/form number — it is a published BSD guidance handout ("Minimum Plan Submittal Requirements — Accessory Dwelling Unit"). The companion Expedited ADU Checklist is versioned "V4.2".
Issuing body: Los Angeles County Department of Public Works, Building and Safety Division (BSD) — Development Services. Applies to unincorporated LA County only.
What it is: A one-page checklist published by LA County Building & Safety that defines the minimum architectural, structural, energy, and administrative documents a new-ADU plan set must contain before it can be accepted for plan check. It is not itself a permit or an application — it is the content standard your drawings have to meet so the intake counter (or EPIC-LA) will accept the submittal. An incomplete set is rejected at intake or stalls in correction cycles, which is the single most common cause of ADU permitting delay.
Who needs it: Anyone building or converting an ADU or JADU on a property in unincorporated LA County (not inside an incorporated city — cities like LA City use LADBS instead; check jurisdiction at the County service locator). You can effectively skip assembling a full custom set if you use one of the County's free pre-approved ADU Standard Plans (A/B/C), since those drawings already satisfy the requirements and cannot be revised. Garage conversions and JADUs may use Standard Notes and Details in place of full structural plans/calcs.
Fees: The checklist itself is free. Costs you will pay in the process: Regional Planning Ministerial Site Plan Review (roughly $1,000+; the 2023 guide listed $977–$1,193 and the fee is updated periodically — confirm current amount). Building & Safety plan-check and permit fees are valuation-based per the County 2025–2026 Building Code Fee / Building Valuation Fee schedules (no flat ADU fee). Plus separate agency clearance fees (Fire, Public Health, sewer/septic) as listed on your Agency Referral sheet. The County's pre-approved ADU Standard Plans themselves are free.
Timeline: Regional Planning approval: about 60 days from fee payment. Building & Safety plan check: review clock starts only after plan-check fees are paid; total time varies with project complexity and number of correction cycles (commonly several weeks to a few months). Pre-approved Standard Plans and expedited review can shorten this. Planning approval is valid 2 years (one-time 1-year extension); the building permit must be pulled within 1 year of application.

Requirements

SITE PLAN + ADMINISTRATIVE — Site plan (lot size, property lines and dimensions, adjacent streets, setbacks, other structures, easements, north arrow, scale, contours/drainage); General Notes (applicable codes, occupancy classification, type of construction, scope of work, lot area, existing/proposed building area, material specs)
ARCHITECTURAL — Floor plans (walls, partitions, doors/windows + schedule, existing vs. new identified for all affected floors); Roof plan (drainage pattern, roofing material/slopes, hips/valleys/ridges, eave overhangs, attic vents); Exterior elevations (wall covering, plate/building heights, openings, roofing, finish grade lines, veneers); Cross sections (full height/width showing framing, foundation, insulation in two orthogonal directions); Door, window, and finish schedules
STRUCTURAL — Foundation plan (new footing locations, anchor-bolt and hold-down schedules, foundation details); Framing plan (size/spacing/span of joists, rafters, beams, headers; all lateral elements incl. shear-wall locations and diaphragm specs); Shear-wall schedule (specs, nailing, allowable capacity); Structural calculations (required if deviating from conventional Residential Code provisions — must address vertical and lateral forces and be wet-stamped and signed by a CA-licensed engineer or architect); Complete framing and foundation details for all new structural elements
ENERGY + GREEN + MISC. — Title 24 Building Energy Efficiency Certificate of Compliance (CF1R); CALGreen requirements/details/notations; Mechanical (HVAC equipment locations + manufacturer specs); Electrical (smoke/CO detector locations, exhaust fan locations and specs); Very High Fire Hazard Severity Zone details/notations per CRC Section R337 where applicable
Solar PV: required for new detached ADUs (2020+ CA Energy Standards) — install before end of construction
Submit as ONE combined PDF via EPIC-LA, or TWO sets of 24-inch x 36-inch paper plans at a County district/contract-city office
Department of Regional Planning approval (Ministerial Site Plan Review) must be obtained before the building permit is issued

How to file

Confirm jurisdiction: verify the property is in unincorporated LA County (Z-NET / DPW service locator). If it is inside a city, you file with that city, not the County.
Get Planning approval first: hire an architect/designer for a full architectural set (site plan, floor plans, elevations) and submit a 'Regional Planning – Base Application' through EPIC-LA. Planning reviews within ~60 days of fee payment and uploads approved plans you can download.
Assemble the plan set to this checklist: produce the architectural, structural, and Title 24 documents listed above. For garage conversions/JADUs, attach the County's Standard Notes and Details instead of full structural calcs where eligible.
Submit to Building & Safety: upload everything as one combined PDF in EPIC-LA, or bring two 24x36 paper sets to a district office (8:00–11:30 AM on business days). Include the completed Expedited ADU Checklist if seeking expedited review.
Pay plan-check fees: once BSD accepts the submittal it invoices plan-check fees. Review time starts only after fees are paid and BSD is notified.
Clear corrections and Agency Referral items: respond in writing to each BSD correction cycle with revised plans, and obtain every clearance listed on your Agency Referral sheet (e.g., Fire, Public Health, Sewer/Septic).
Pull the permit: after approval and all agency verifications, pay the permit fee and pull the building permit within 1 year of the application date (extendable on request). Garage-conversion/Standard-Notes projects must schedule a pre-construction meeting before starting work.

Common pitfalls

Submitting before Regional Planning approval — BSD will plan-check, but the permit cannot be issued until Planning (and all Agency Referral items) clear.
Filing with the County when the property is inside an incorporated city — wrong jurisdiction means automatic rejection.
Missing Title 24: no CF1R energy compliance certificate, or window U-factor/SHGC and insulation values not carried onto the plans.
Forgetting solar PV on a new detached ADU (required by CA Energy Standards) and the solar-ready zone on the roof plan.
Structural calcs not wet-stamped and signed by a CA-licensed engineer/architect when the design deviates from conventional Residential Code provisions.
Plans that don't clearly distinguish existing vs. new construction, or omit the shear-wall schedule / hold-down details.
Not uploading EPIC-LA submittals as one combined PDF, or bringing only one paper set instead of two 24x36 sets.
Ignoring fire requirements: 1-hr fire separation + STC 50 for attached ADUs, R337 notes in fire hazard severity zones, and matching the ADU sprinkler status to the main house.
Assuming review has started before paying the plan-check invoice — the clock only runs after fees are paid and BSD is notified.

Sources

Explore more:Permits & Feasibility

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