Site-Specific Plot Plan (LA County ADU)

The Site-Specific Plot Plan: The One ADU Document LA County Reviewers Reject Most If you're building an accessory dwelling unit ADU or backyard tiny home in...

Written by 1-800-ADU-Pros

Last updated: July 16, 2026•7 min read

Site-Specific Plot Plan (LA County ADU)

The Site-Specific Plot Plan: The One ADU Document LA County Reviewers Reject Most

If you're building an accessory dwelling unit (ADU) or backyard tiny home in unincorporated Los Angeles County, there's a single sheet of paper that quietly decides how fast your project moves: the site-specific plot plan. It's filed with the LA County Department of Regional Planning (DRP), and it's one of the most common spots where homeowners get a correction notice. Here's what it is and how to get it right the first time.

What a Site-Specific Plot Plan Actually Is

A site-specific plot plan is a scaled, top-down drawing of your exact lot, done on LA County's official template. It shows how your ADU fits the property: where the property lines are, how far the ADU sits from them (your setbacks), how tall it is, where every existing structure already stands, and where driveways, parking, and street or alley access fall.

Think of it as the bridge between a generic building design and your specific dirt. This matters most if you're using one of the County's pre-approved Standard Plans — either the free County Catalog or the Private Designer Catalog. With those, the building itself is already approved, so the plot plan is the piece that proves the pre-approved unit actually fits your yard within the zoning rules.

Who Needs One (and Who Can Skip It)

You need a DRP-approved plot plan if your property is in unincorporated LA County and you're filing through the County. If you're inside an incorporated city — the City of Los Angeles, Long Beach, Pasadena, and so on — you do not use Regional Planning or the County's EPIC-LA portal at all. Those cities run their own planning departments. So step one is always: confirm your address is unincorporated.

What the Plot Plan Has to Show

Reviewers are looking for a clean, to-scale drawing on the County template with all of the following:

The lot itself

Property boundaries with dimensions and total lot size
A north arrow (oriented toward the top of the page) and a stated scale
Any easements, zone lines, or highway dedication lines

The structures

Every existing building — house, garage, sheds — not just the new ADU
The proposed ADU, with distances measured to each property line and to other structures
Driveways, parking, and how you access the lot from the street or alley

The numbers that get checked hardest

Setbacks. Detached ADUs are typically allowed at 4 feet from the side and rear property lines. This is the single most common rejection point.
Height and number of stories.
Lot coverage.

How to File It, Step by Step

Confirm your parcel is unincorporated LA County.
If using a pre-approved plan, pick one from the County Catalog. Heads up: the catalog is being updated to match the building codes that took effect January 1, 2026.
Download the Site-Specific Plot Plan Template from the Regional Planning ADU page and draw your lot on it to scale.
Log into EPIC-LA, the County's online permitting portal.
Submit a "Regional Planning – Base Application – Permits and Reviews" and upload your completed plot plan. You'll get an RPAP case number that converts to an RPPL number once accepted.
Pay the review fee when invoiced — review starts after payment.
Once approved, download your stamped plot plan set and carry it into the building-permit stage at Public Works Building & Safety.

Fees and Timeline

The pre-approved Standard Plans themselves are free. Regional Planning charges a review fee per its current fee schedule (effective March 1, 2026), billed after you file. Building-permit and school fees come later and separately.

On timing, California ADU law requires the County to approve or deny a complete application within 60 days. A clean plot plan can clear DRP in a few weeks; a sloppy one that bounces for corrections drags the whole project.

The Pitfalls That Cost People Weeks

Submitting a generic contractor site plan instead of the County's actual template.
Wrong or missing setbacks (the 4-foot rule trips up the most people).
No north arrow, no scale, or a drawing that isn't truly to scale.
Forgetting to show every existing structure and its distance to the ADU.
Trying to pull a building permit before the plot plan is approved — it's a prerequisite, not a parallel step.
Letting a correction notice sit. The clock and your build both stall until you respond.

Get the plot plan tight, and the rest of your ADU permitting gets a lot smoother. Questions on your specific lot? Regional Planning takes calls at (213) 974-6411.

Reference card

Official number: No standalone form number. Filed as the "Site-Specific Plot Plan Template" attached to a "Regional Planning – Base Application – Permits and Reviews" (Base Application = RPAP case number; converts to an RPPL plan number once accepted). Standard plot plan sheet example: adu_standard_plan_c.pdf.
Issuing body: Los Angeles County Department of Regional Planning (DRP)
What it is: A scaled, to-spec drawing of your specific lot on LA County's template that shows exactly where the ADU (or a pre-approved Standard Plan) will sit — property lines with dimensions, setbacks, height, all existing and proposed structures, driveways/parking, and a north arrow and scale. It is the document Regional Planning reviews to confirm your ADU fits the zoning rules for your parcel. For a pre-approved Standard Plan (County Catalog or Private Designer Catalog), the building design is already blessed, so the site-specific plot plan is the piece that ties that generic plan to your actual property. Once DRP approves it, you get an approved "Site-Specific Plot Plan Set" that you carry into the building permit (Public Works Building & Safety) stage.
Who needs it: Anyone building an ADU on a property in unincorporated LA County who is using a pre-approved Standard Plan needs this DRP-approved site-specific plot plan before they can pull a building permit. Custom-designed ADUs also need a plot plan/site plan as part of their plan set, but Standard Plan users in particular must route it through the Regional Planning Base Application. You can skip the DRP step entirely if your property is inside an incorporated city (e.g., the City of Los Angeles, Long Beach, Pasadena) — those have their own planning departments and EPIC-LA does not cover them. Confirm your address is unincorporated first.
Fees: No flat published ADU plot-plan fee. The pre-approved Standard Plans in the County Catalog are free; Regional Planning charges a plan/plot-plan review fee per its current fee schedule (effective March 1, 2026), billed after you file the Base Application. Building-permit and school fees are separate and come later at Building & Safety. Check the live schedule at planning.lacounty.gov/fees or call (213) 974-6411 for your exact amount, since fees update annually by a cost index.
Timeline: Under California ADU law, the County must approve or deny a complete ADU application within 60 days of submittal. In practice, expect a few weeks of DRP plot-plan review (faster if the drawing is clean, longer if it bounces back for corrections), then a separate Building & Safety plan-check timeline for the actual building permit afterward.

Requirements

A site-specific plot plan drawn on LA County's template, to scale and legible (commonly 11"x17" reduced set), with north oriented toward the top of the page
Property boundaries with dimensions and total lot size
All required setbacks called out (detached ADUs are typically 4 ft from side and rear property lines)
ADU height and number of stories
All existing structures (primary dwelling, garage, etc.) and the proposed ADU, with distances between them
Driveways, parking areas, and street/alley access
Easements, lot coverage, and any zone or highway dedication lines that apply
Your selected pre-approved Standard Plan reference (County Catalog or Private Designer Catalog) if using one
An EPIC-LA account to file the Regional Planning Base Application

How to file

Confirm your parcel is in unincorporated LA County (incorporated cities use their own planning department, not DRP/EPIC-LA).
If using a pre-approved plan, pick one from the County Catalog (free) or the Private Designer Catalog. Note the catalog is being updated for the building codes effective Jan 1, 2026.
Download the Site-Specific Plot Plan Template from Regional Planning's ADU page and draw your lot on it to scale — setbacks, height, all structures, north arrow and scale.
Create or log into an EPIC-LA account at planning.lacounty.gov/epic-la.
Submit a 'Regional Planning – Base Application – Permits and Reviews' and upload your completed site-specific plot plan. You'll get an RPAP number that becomes an RPPL once accepted.
Pay the Regional Planning fee when invoiced; review begins after payment.
Respond promptly to any DRP corrections (setback or dimension issues are the usual ones).
Once approved, download the stamped Site-Specific Plot Plan Set.
Take that approved set into the building-permit stage: submit a Residential New Construction Building Permit at your local Building & Safety District Office or via EPIC-LA and upload the approved plot plan set.

Common pitfalls

Using a generic contractor site plan instead of LA County's actual template — DRP wants it on their sheet, to scale
Missing or wrong setbacks (the 4 ft side/rear for detached ADUs is the most common rejection point)
No north arrow or no stated scale, or a drawing that isn't actually to scale
Forgetting to show ALL existing structures and the distances between them and the new ADU
Assuming your city is covered — EPIC-LA and DRP only handle unincorporated areas; incorporated cities file with their own planning dept
Trying to pull a building permit before the plot plan is DRP-approved — the approved plot plan set is a prerequisite
Using an outdated Standard Plan; the County Catalog is being revised for the Jan 1, 2026 code update
Letting correction notices sit — the 60-day clock and your project both stall until you respond

Sources

Explore more:Permits & Feasibility

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