ADU permit cost and fee breakdown in San Carlos, California
GetYourPermit’s researched permit-fee range for a detached accessory dwelling unit in San Carlos, 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
$7,290 – $12,850
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
$9,780
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$240 – $550
Shown only where the City bills Planning or zoning review as a separate fee.
- Building plan check$1,880 – $3,050
The Building Division’s review of the drawings; part of the Building Permit process.
- Building permit issuance$2,320 – $3,950
The permit issuance charge; where plan check is bundled, the combined amount is carried here.
- Separate trade permits$420 – $880
Shown separately only where electrical, plumbing, or mechanical permits are billed outside a combination permit.
- School district fees$1,950 – $2,750
Possible school-district developer fees based on current thresholds and scope.
- Utility fees$180 – $900
Possible water, sewer, electrical, meter, or capacity-related charges.
- Processing, inspection & records$180 – $400
Fixed processing, inspection, records, and administrative charges.
- Surcharges, taxes & state fees$120 – $370
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 |
|---|---|---|---|
| Valuation-based building permit | From $348 | Formula | FY 2026-27 Cost of Services — Building Department FeesLocation: FY 2026-27 Building Fees, page 1, Building Permits (single Family Residential)Confirms: The current City fee schedule gives the residential building permit base fees and valuation increments. |
Plan check
Review of your drawings for code compliance.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| Valuation-based plan check | From $291 | Formula | FY 2026-27 Cost of Services — Building Department FeesLocation: FY 2026-27 Building Fees, page 1, Plan Check FeeConfirms: The current City fee schedule gives the residential plan-check base fees and valuation increments. |
Impact fees
Development impact fees. Prohibited for ADUs of 750 sq ft or less.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU/JADU impact-fee exemption | $0 | Flat fee | Building an Accessory Dwelling UnitLocation: Building an Accessory Dwelling Unit, Applying for a Permit and FeesConfirms: The City states no impact fees are collected on a JADU or ADU below 750 square feet. |
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 San Carlos before you commit money.
City reference pages for verification
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