- Total LADBS permit cost for a typical 600 sqft ADU in 2026: $8,000 to $15,000 across all fee categories combined.
- Architectural / design fees (separate from LADBS): $10,000 to $25,000 for custom plans, or a modest licensing fee for the LADBS Standard Plan Program.
- First-permit timeline: 3 to 6 months in practice. 60 days under state law if the submission is complete on day one, which it rarely is on a first submission.
- The hidden cost layer: each correction round adds 4 to 8 weeks of waiting and $1,500 to $5,000 in architect re-work fees that never appear on any contractor bid.
- The most expensive timing mistake: signing an architect contract before Feasibility confirms the lot supports the project. Sometimes the right answer is not to build — and we say that clearly, before any money moves.
What Actually Appears on the Invoice
These are the fees that appear on an LADBS permit invoice for a typical detached 600 sqft ADU in 2026. Ranges reflect actual LADBS fee schedule numbers and variability by jurisdiction layer (LA City vs. unincorporated LA County vs. small incorporated cities within the LA metro).
The base permit fee scales with square footage. For a 600 sqft ADU, this is $300 to $540. The rate per sqft varies by building valuation tier; larger or higher-finish units land at the upper end.
Plan check is the structural and code-compliance review LADBS performs before issuing the permit. Invoiced as a percentage of the building permit fee. For a 600 sqft ADU, typically $200 to $350.
Mechanical, Electrical, and Plumbing each require their own permit. Flat-fee per trade, scaled by fixture count and system complexity. For a standard 600 sqft ADU with one bathroom, one kitchen, and a heat-pump HVAC system.
Required for all new residential construction in LA City. Documentation must accompany the plan-check submission.
Gov Code §65852.2 waives most local sewer and water connection fees for ADUs under 750 sqft. The waiver does not cover physical capacity upgrades to the sewer lateral or service line; those are private construction costs.
Triggered by total bathroom count across the property. A 1-bathroom ADU on a 2-bathroom main house rarely triggers it. Above-threshold fees can exceed $3,000.
Most jurisdictions waive these for ADUs under the state-law size threshold. Outside that threshold, they re-appear and can add $500 to $2,000 combined.
Not part of the permit issuance fee stack — surfaces during construction. Top-quartile LA ADU contractors clear inspections on the first pass more than 90% of the time; bottom-quartile contractors fall below 65%, per InspectPilot data covering 11 million California construction records since 2013. The cost of a low-pass-rate contractor compounds across 5 to 7 inspections.
What the Invoice Actually Looks Like
For a typical 600 sqft detached ADU in LA City, 2026:
| Fee category | Typical range |
|---|---|
| Building Permit | $300 to $540 |
| Plan Check | $200 to $350 |
| MEP (combined) | $1,200 to $2,500 |
| LA Green Building Code surcharge | $200 to $500 |
| School fees | $0 (≤750 sqft) |
| Sewer / water connection | $0 (waived under state law) |
| Library, park, Mello-Roos, misc. | $0 to $1,500 |
| Total LADBS permit cost | $8,000 to $15,000 |
Outside LA City (Long Beach, Pasadena, Santa Monica, Culver City, unincorporated LA County under LACDPW), the totals shift modestly. Pasadena and Santa Monica run on the higher end. Unincorporated LA County is often comparable to LA City. Smaller cities can be 10% to 20% lower because their plan-check overhead is lighter.
The Realistic Schedule from ePlanLA to Permit Issuance
The 60-day shot clock under Gov Code §65852.2 starts only when LADBS deems the submission complete. The submission completeness check is itself a step, and it is where most timelines lengthen.
Three Reasons That Dominate — Each With a Fix
Three reasons dominate submission failures. Each has a specific fix at the Feasibility stage.
Missing soils report.
Required for any lot in a Hillside Construction Regulation zone, on a slope above 5%, or in a liquefaction-susceptibility area. About 1 in 4 LA residential lots triggers this. Fix: order the report before plan submission, not after.
Incomplete Title 24 plus LA Green Building Code documentation.
California energy code (Title 24) and LA Green Building Code use separate forms. Submitting only one is the most common documentation gap. Fix: confirm both stacks are in the package.
Setback / coverage calculation errors.
Generic state-law numbers applied without LA overlays (hillside, HPOZ, fire-hazard severity zone). Fix: site-specific overlay confirmation at Feasibility.
LA ADU Permit Cost and Timeline, 2026
LADBS issued 7,160 ADU permits in LA City in 2022 alone, up from 80 in 2016 — an 89x increase per the CA YIMBY ADU Reform Retrospective, January 2024.
State-law shot clock: plan check must complete within 60 days of a complete submission per Gov Code §65852.2. Median LA first-permit timeline runs 3 to 6 months because of correction rounds.
Re-inspection fees: $600 to $1,000+ per failed visit per LADBS published fee schedules. Top-quartile pass rate: 90%+; bottom-quartile: below 65% per InspectPilot (11 million CA construction records).
School impact fees: waived for ADUs 750 sqft and under under AB 68; reappear at ~$5/sqft above the threshold.
AB 1332 Standard Plan Program required every California city to publish pre-approved ADU plans by 2025. LADBS Standard Plans can shave 4 to 8 weeks off plan check and skip the architect fee entirely.