ADU permit cost and fee breakdown in Larkspur, California
GetYourPermit’s researched permit-fee range for a detached accessory dwelling unit in Larkspur, with category estimates and direct reference links used in our investigation.
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ADU size
California prohibits development impact fees for ADUs of 750 sq ft or less, so the 749 / 750 / 751 steps are worth comparing.
Estimated total
GetYourPermit researched range at 750 sq ft
$7,320 – $10,845
This estimate combines our fee-schedule research and project-planning experience. Actual charges vary by parcel, plans, valuation, utilities, and outside agencies.
Typical planning amount
$8,945
Modeled at the 600 sq ft reference.
Where the money goes
These are fee components within the permit process, not separate approvals.
- Separate planning / zoning fee$500 – $800
Shown only where the City bills Planning or zoning review as a separate fee.
- Building plan check$1,850 – $2,900
The Building Division’s review of the drawings; part of the Building Permit process.
- Building permit issuance$1,550 – $2,450
The permit issuance charge; where plan check is bundled, the combined amount is carried here.
- Separate trade permits$500 – $800
Shown separately only where electrical, plumbing, or mechanical permits are billed outside a combination permit.
- School district fees$2,550 – $3,300
Possible school-district developer fees based on current thresholds and scope.
- Utility fees$75 – $200
Possible water, sewer, electrical, meter, or capacity-related charges.
- Processing, inspection & records$200 – $245
Fixed processing, inspection, records, and administrative charges.
- Surcharges, taxes & state fees$95 – $150
Percentage surcharges, construction taxes, and State-mandated charges.
The darker segment is the low end of the range; the full bar is the high end.
Published fee references
Building permit issuance
The permit issuance charge; where plan check is bundled, the combined amount is carried here.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| Building Permit fee by valuation | From $138 | Formula | Schedule of User and Regulatory FeesLocation: FY2026-27 Schedule, Building Permit Valuation FeeConfirms: The current schedule provides valuation brackets and a $138 minimum permit fee. |
Plan check
Review of your drawings for code compliance.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| Building plan-review fee | Set by City formula | Formula | Schedule of User and Regulatory FeesLocation: FY2026-27 Schedule, Plan Review FeeConfirms: The current schedule defines the City plan-review method. |
Impact fees
Development impact fees. Prohibited for ADUs of 750 sq ft or less.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU Road Impact Fee exemption | $0 | Flat fee | Schedule of User and Regulatory FeesLocation: FY2026-27 Schedule, Road Impact Fee noteConfirms: The current schedule expressly excludes ADU permits from the Road Impact Fee. |
These are estimates, not official fees
Use these figures for early budgeting only. They are not a quote, not a government fee determination, and not legal advice. Actual fees depend on your parcel, your plans, your construction valuation, your utility provider, and the fee schedule in force on the day your permit is issued. Confirm every number with Larkspur before you commit money.
City reference pages for verification
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