How to Legalize an Unpermitted ADU in Los Angeles

Updated October 2026

If your unpermitted ADU was built before January 1, 2020, the City of Los Angeles can’t deny a permit because it misses today’s zoning or building code. It can only deny for real health and safety problems. That is AB 2533, in force since January 1, 2025.

The short version

• Who qualifies: ADUs and JADUs built before January 1, 2020 that meet the state definition of an ADU or JADU.
• What the city can’t require: current zoning standards (setbacks, size, height), current building and energy code, or impact and utility connection fees unless a health or safety fix needs them.
• What it can deny for: conditions that make the unit substandard under Health and Safety Code 17920.3, such as unsafe wiring, structural hazards, or missing plumbing or heat.
• LADBS process: set out in Information Bulletin P/BC 2026-161.

How the LA process works

1. Prove the date. Any record that shows the unit existed before 2020: RSO registration, contractor bills or receipts, utility or insurance records, code enforcement records, signed leases, appraisals or MLS listings.
2. Prepare the submittal. A site plan with property lines, setbacks, dimensions and the ADU’s location. The latest certificate of occupancy and permits for existing buildings. LADBS’s standard notes form. A full construction set is not required.
3. Pay plan check fees. Other impact fees are waived. LAUSD school fees apply to units over 500 sf.
4. Inspection. An inspector walks the unit with the City’s 37-item substandard checklist: smoke and CO alarms, egress windows, plumbing, electrical, mechanical, structure, fire separation, weather protection and mold.
5. Correct and final. Fix anything on the correction notice, pass reinspection, and the unit is permitted. The unit can follow the code in effect when it was built or current code.

What to watch out for

• Built in 2020 or later? AB 2533 doesn’t apply. You go through the normal ADU permit, which must be decided within 60 days of a complete application.
• Not an ADU? An extra unit inside a multifamily building may not meet the ADU definition. LA’s separate Unpermitted Dwelling Unit ordinance (Ord. 184,907) covers some of these, and it requires one affordable unit for each unit legalized.
• Corrections cost money. Structural or electrical fixes can be real work. Get the unit looked at before you list the property or refinance.

You don’t need an architect for a simple AB 2533 case. You do if the unit needs structural repairs, if you want to add space, or if the lot could hold more than a legalized ADU.

How we use it

Legalizing is often the first step, not the last. Once the existing unit is on record, we look at what else the lot can hold. Randolph Complex puts two homes over a three-car garage on a hillside lot. On vacant single-family lots, SB 1123 can allow up to ten. See SB 684 / SB 1123.

Sources: LADBS IB P/BC 2026-161, LA City Planning, UDU ordinance.

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