How much does an ADU permit cost in Los Angeles?
Permit and plan check fees for a new ADU in Los Angeles run $5,000 to $14,000 in 2026. A garage conversion is much cheaper — typically $1,500 to $2,500 in total city fees for a standard 400 sq ft conversion. The number is driven by the construction valuation you declare to LADBS, plus plan check (roughly 80% of the permit fee on top), state surcharges, and — the one that surprises people — LAUSD school fees of $4.79 per square foot if your ADU is over 500 square feet. Keep it at 500 sq ft or under and school fees disappear; keep it under 750 sq ft and impact fees are prohibited by state law.
The short answer, in one table
| Project | Typical total city fees (2026) |
|---|---|
| Garage conversion (~400 sq ft) | $1,500 – $2,500 |
| New detached ADU, ≤500 sq ft | $4,000 – $8,000 |
| New detached ADU, 501–749 sq ft | $6,000 – $11,000 |
| New detached ADU, 750+ sq ft | $8,000 – $14,000+ |
These are typical 2026 Los Angeles market ranges for LADBS-jurisdiction projects, not a quote. Burbank and Glendale have their own building departments and fee schedules — usually in the same ballpark, but calculated differently.
What the fee is actually based on
LADBS does not charge a flat ADU fee. The building permit fee is calculated on a sliding scale from the construction valuation you declare on the application — not what your contractor actually charges you. A $250,000 declared valuation lands around $3,900 in building permit fees alone, and then plan check adds roughly 80% of the permit fee on top of that.
Then come the smaller lines that add up:
- State surcharges — SB 1473 and CalGreen, each $4 per $100,000 of valuation
- LADBS records management — about $160
- Electrical, plumbing, mechanical permits — pulled separately, a few hundred dollars each
- Sewer connection / utility fees — varies by site, and can be the biggest "permit" line on some lots
The two thresholds that decide everything
500 square feet. LAUSD school fees are $4.79 per square foot of new residential construction — and ADUs at or under 500 sq ft are exempt. Cross the line to 501 and the whole unit's footage is billed. On a 749 sq ft ADU that is roughly $3,600 that a 500 sq ft unit simply does not pay.
750 square feet. California law prohibits cities from charging development impact fees on ADUs under 750 sq ft. This is exactly why so many Los Angeles ADUs come in at 749 square feet — it is not a coincidence, it is fee engineering.
If you are on the fence about size, these two numbers should be part of the design conversation on day one, not a surprise at the permit counter. It is the same logic we walk through in our post on what a full ADU costs in Los Angeles — the fees are small next to construction, but they are the part you can actually control with smart design.
How to keep the fee bill down
Use a pre-approved standard plan. LADBS maintains a list of pre-approved ADU designs that skip most of architectural plan check — saving 4 to 8 weeks of review time and $4,000–$8,000 in design fees. The trade-off is less customization.
Do not inflate the declared valuation. The fee scales with it. Declare honestly — but there is no reason to round $180,000 up to $250,000 "to be safe."
Convert instead of building new, if the garage is sound. A garage conversion pays a fraction of the city fees of a new build because the square footage already exists.
Permits are the cheap part
Keep perspective: on a $200,000 ADU, city fees are 3–5% of the project. The expensive mistakes are not at the permit counter — they are under the slab, in the electrical panel, and in the sewer lateral. A licensed contractor who has run this process will fold the fee strategy into the design instead of treating it as an afterthought.
DN Builders Group Inc is a licensed, bonded general contractor based in Burbank (CA Lic. #1139710). See our home additions & ADUs page, our breakdown of permit timelines in Burbank, or request a site walkthrough. Figures are typical 2026 Los Angeles market ranges, not a quote, and this is general information rather than legal or financial advice.
Questions
Why is my neighbor's ADU permit so much cheaper than my quote?
Almost always one of three reasons — theirs was a garage conversion (a fraction of new-build fees), theirs was at or under 500 sq ft so no school fees applied, or they used a pre-approved standard plan that skipped most of architectural plan check. Two ADUs of similar size can have city fee totals thousands of dollars apart because of these thresholds.
How long does ADU plan check take at LADBS in 2026?
Standard plan check runs about 4 to 10 weeks, and the express program 2 to 4 weeks for projects that qualify. State law caps ADU application review at 60 days once the application is complete — but an incomplete submittal restarts the clock, which is where most delays actually come from.
Are permit fees included in a contractor's bid?
Sometimes, and you should never assume. Many bids list permits as an allowance or exclude them entirely. Ask directly whether the number includes LADBS permit and plan check fees, school fees, and utility connection fees. At DN Builders we itemize city fees separately so you can see exactly what goes to the city versus construction.
Do I pay school fees on a garage conversion?
Usually not. LAUSD school fees apply to new residential square footage over 500 sq ft, and most garage conversions are existing square footage under that threshold. A new detached ADU over 500 sq ft pays $4.79 per square foot — on a 749 sq ft unit that is about $3,600.