Are LA's pre-approved standard ADU plans worth it for a Valley homeowner?

What is LA's Standard Plan Program for ADUs?

It is a catalog of backyard house designs that LADBS (the Los Angeles Department of Building and Safety) has checked ahead of time. Private licensed architects and engineers draw the plans, and LADBS pre-approves them against the building, residential and green codes ¹.

There are two kinds of plan in the catalog:

• The city's own plan. The YOU-ADU is a one-story, one-bedroom design of 455 square feet that the city provides free to applicants ³. You can submit it yourself or have an architect or contractor of your choice do it ³.
• Privately owned plans. Every other plan belongs to the designer. LADBS says you must contract with the design professional to use their pre-approved plan, and you coordinate directly with the plan owner for access, pricing and terms of use ².

LADBS also says that pre-approving a plan is not an endorsement of the designer or of their ability to complete the work ². Treat the catalog as a list of approved drawings, not a list of recommended firms.

What does a standard plan actually save me?

It saves the time and cost of designing the building from scratch, and it shortens plan check. LADBS says using standard plans shortens the time needed to review the plans through plan check, and permits are issued more quickly ¹.

State law adds a deadline. Under AB 1332, every city had to set up a preapproval program by January 1, 2025, and for a detached ADU that uses a preapproved plan, the city must approve or deny the application within 30 days of receiving a completed application ⁵. For other ADU applications on a lot with an existing house, the state deadline is 60 days ⁶. The clock starts at a complete application, so it does not count the time you spend preparing the site drawings. Our guide to the LADBS ADU plan check timeline covers the rest of the wait.

It does not lower the city's fees. LADBS says that once an owner chooses a pre-approved plan, building plan check and permit fees are based on the total project valuation, meaning the total cost of construction ². A standard plan of the same size and cost pays the same plan check and permit fees as a custom one. The other soft costs, from school fees to utility work, are covered in our guide to ADU soft costs in Los Angeles.

What does LADBS still review on my lot?

LADBS still reviews how the building sits on your particular lot, and that review can change the job. LADBS says that if you choose an approved plan, it will review it to make sure it fits your property, following zoning codes and foundation needs ¹. Its own submittal checklist answers the question of why a pre-approved plan goes through plan check again: the department verifies site-specific factors, including Zoning Code compliance and foundation requirements ⁴.

In practice that review touches the same things any backyard house runs into:

• Placement. The plot plan must show property lines, front, side and rear setbacks, the distance between the existing house and the new one, site drainage and driveways ⁴. See ADU setbacks in California and ADU height limits in LA.
• Foundation. LADBS warns that localized soil conditions may require site-specific foundation work, structural designs or detailed engineering to support the design ². A plan drawn for a typical lot does not know what is under yours.
• Clearances. The ADU plan check correction sheet tells applicants to obtain all clearances on the Clearance Summary Worksheet and says it can take months for some departments to review a project ⁷. A standard plan does not skip those departments.

None of the site questions go away either: whether the sewer main is close enough, whether your electrical panel and water meter can carry a second home, and whether you are in a fire zone or near a protected tree.

What do I have to turn in when I use a standard plan?

You turn in the approved plan plus drawings that show how it fits your lot. LADBS's Standard Plan submittal checklist lists three parts: a title sheet with area calculations, a plot plan with notes, and a complete copy of the approved Standard Plan drawings ⁴. Applications and plans go in through ePlanLA ⁴.

1. Title sheet. It includes floor area calculations, the lot's APN (assessor parcel number), legal description, zone and lot area, fire sprinkler information, existing structures and parking ⁴. LADBS points you to ZIMAS, the city's zoning map, for the parcel details ⁴.
2. Plot plan. Everything on it must be drawn to scale: property lines with dimensions, setbacks, separation between buildings, site drainage, the footprint of the existing house and the driveway and parking areas ⁴.
3. The plan itself. For a privately owned plan, LADBS's general program page says you need a wet-stamped and signed copy of the Standard Plan, along with plans showing how it will be adapted to your site ².

The plot plan is where most of the work on your lot shows up. Someone still has to measure the lot and draw it, and if the design has to move or change to fit, LADBS notes that adjustments may result in additional costs and may require additional reviews by the city ².

How many Valley homeowners actually use a standard plan?

Very few, judging by the permits. We searched the LADBS permit records for new-building ADU permits issued since January 2023 and looked for descriptions that name a standard or pre-approved plan ⁸. In the San Fernando Valley (the North Valley and South Valley planning areas), 9 of 3,317 permits did. Citywide it was 31 of 6,338 ⁸.

That count is a floor, because a permit description does not always name the plan it was built from. Even so, it shows that almost everyone building a backyard house in the Valley is using a design drawn for their own lot. The Valley permits that did name one were in Pacoima (91331), Granada Hills (91344), North Hills (91343), Northridge (91325), Van Nuys (91406) and Studio City (91604), among others ⁸.

For comparison, Valley ADU permit counts by ZIP are in our guide to ADU permits in the San Fernando Valley by ZIP.

When is a standard plan a good fit, and when is it not?

A standard plan is a good fit when you want one of the designs as drawn, your lot has room for its footprint inside the setbacks, and the soil and utilities are ordinary. LADBS puts the risk plainly: every property is unique, a pre-approved design may not work for your property due to site-specific constraints, and you should verify with LADBS that the design works for your property before you contract with a professional ².

It is a weaker fit in these cases:

• You want changes. LADBS says pre-approved designs may or may not be customizable, and you have to ask the designer ². Changes can bring added cost and review ².
• You are converting a garage. A standard plan is a design for a new building. A conversion starts from the structure you already have, which is covered in how to check whether your garage was permitted.
• Your lot is tight or unusual. On a narrow, sloped or deep lot, the footprint may not fit, and the ADU types that fit a 6,600 sq ft lot depend on the lot more than the plan.

Before you pay for a plan, you can ask. The checklist lists a short in-person session with a plan check engineer through the city's appointment system, and an optional Preliminary Plan Check appointment ⁴. LADBS also offers an AI pre-plan check tool to catch issues before you submit ². Knowing your setbacks, utilities and clearances before you pick a design is the kind of thing a lot check settles.

Quick answers

Sources

1. Accessory Dwelling Unit (ADU): ADU Approved Standard Plans Program, Los Angeles Department of Building and Safety (LADBS). Facts checked 2026-10-09
2. Standard Plan Program, Los Angeles Department of Building and Safety (LADBS). Facts checked 2026-10-09
3. YOU-ADU: Pre-Approved, City-Provided ADU Standard Plan, Los Angeles Department of Building and Safety (LADBS). Facts checked 2026-10-09
4. Standard Plan – Building Permit Submittal Checklist, Los Angeles Department of Building and Safety (LADBS). Facts checked 2026-10-09
5. Assembly Bill No. 1332, Chapter 759, Statutes of 2023 (Gov. Code § 65852.27), California Legislature (chaptered bill, copy hosted by CALBO). Facts checked 2026-10-09
6. Accessory Dwelling Unit Handbook (March 2026), California Department of Housing and Community Development (HCD). Facts checked 2026-10-09
7. ADU Plan Check Correction Sheet (PC/STR/Corr.Lst.20A1), Los Angeles Department of Building and Safety (LADBS). Facts checked 2026-10-09
8. Building and Safety - Building Permits Issued from 2020 to Present (N), dataset pi9x-tg5x (Greenlight standard-plan query), City of Los Angeles Open Data / LADBS. Facts checked 2026-10-09

Greenlight is not a contractor, architect or engineer, and this is not legal advice. Rules change; every fact here shows the date we last checked it.