ADU permit cost and fee breakdown in Petaluma, California
GetYourPermit’s researched permit-fee range for a detached accessory dwelling unit in Petaluma, 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
$13,410 – $19,688
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
$16,493
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$182
Shown only where the City bills Planning or zoning review as a separate fee.
- Building plan check$3,906 – $5,232
The Building Division’s review of the drawings; part of the Building Permit process.
- Building permit issuance$3,906 – $5,232
The permit issuance charge; where plan check is bundled, the combined amount is carried here.
- Separate trade permits$750 – $1,400
Shown separately only where electrical, plumbing, or mechanical permits are billed outside a combination permit.
- School district fees$2,100 – $3,100
Possible school-district developer fees based on current thresholds and scope.
- Utility fees$500 – $1,200
Possible water, sewer, electrical, meter, or capacity-related charges.
- Processing, inspection & records$200 – $375
Fixed processing, inspection, records, and administrative charges.
- Surcharges, taxes & state fees$1,866 – $2,967
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 project valuation | From $94 | Formula | FY 2026-27 Master Fee Schedule with Fee Study UpdatesLocation: FY2026-27 Master Fee Schedule, Building, page 2Confirms: The current City schedule publishes the complete valuation-tier Building Permit formula; the City ADU FAQ confirms ADUs use the City permit process. |
Plan check
Review of your drawings for code compliance.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| Building Permit plan-check fee | 100% formula | Formula | FY 2026-27 Master Fee Schedule with Fee Study UpdatesLocation: FY2026-27 Master Fee Schedule, Building Plan Checks, page 2Confirms: The effective City Building table sets the Building Permit plan-check charge equal to the Building Permit fee. |
| Planning plan-check fee | $182 | Flat fee | FY 2026-27 Master Fee Schedule with Fee Study UpdatesLocation: FY2026-27 Master Fee Schedule, Building Plan Checks, page 2Confirms: The current City schedule separately lists a $182 Planning Plan Check fee. |
Impact fees
Development impact fees. Prohibited for ADUs of 750 sq ft or less.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU development-impact-fee exemption and proportional rule | Verify on the City’s official website | Formula | Accessory Dwelling Units FAQ’sLocation: Accessory Dwelling Units FAQ, development impact fees answer; Development Impact Fees pageConfirms: The current City FAQ establishes the exemption and proportional rule, while the City directs project-specific impact/connection estimates to Planning rather than presenting a current FY2026-27 numeric matrix. |
Surcharges, taxes & state fees
Percentage surcharges, construction taxes, and State-mandated charges.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| Building supplemental City and State fee formulas | From $1 | Formula | FY 2026-27 Master Fee Schedule with Fee Study UpdatesLocation: FY2026-27 Master Fee Schedule, Building supplemental rows, page 2Confirms: The current schedule identifies separately calculated incremental, residential seismic, State Building Standards Commission, and energy charges. |
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 Petaluma before you commit money.
City reference pages for verification
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