ADU permit cost and fee breakdown in Cupertino, California
GetYourPermit’s researched permit-fee range for a detached accessory dwelling unit in Cupertino, 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
$11,568 – $16,068
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
$13,768
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$300 – $650
Shown only where the City bills Planning or zoning review as a separate fee.
- Building plan check$3,908
The Building Division’s review of the drawings; part of the Building Permit process.
- Separate trade permits$0 – $450
Shown separately only where electrical, plumbing, or mechanical permits are billed outside a combination permit.
- School district fees$2,700 – $5,200
Possible school-district developer fees based on current thresholds and scope.
- Utility fees$350 – $1,300
Possible water, sewer, electrical, meter, or capacity-related charges.
- Processing, inspection & records$4,010
Fixed processing, inspection, records, and administrative charges.
- Surcharges, taxes & state fees$300 – $550
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
Plan check
Review of your drawings for code compliance.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU plan check, up to 499 square feet | $2,691 | Flat fee | FY 2025-26 Fee Schedule D — Building FeesLocation: Schedule D, PDF page 25, ADU Plan Check Fees — up to 499 sq. ft.Confirms: The effective City schedule lists $2,691 for this ADU plan-check band. |
| ADU plan check, 500–999 square feet | $3,908 | Flat fee | FY 2025-26 Fee Schedule D — Building FeesLocation: Schedule D, PDF page 25, ADU Plan Check Fees — 500–999 sq. ft.Confirms: The effective City schedule lists $3,908 for this ADU plan-check band. |
Impact fees
Development impact fees. Prohibited for ADUs of 750 sq ft or less.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| City impact-fee applicability for ADUs | Set by City formula | Formula | Accessory Dwelling UnitsLocation: Accessory Dwelling Units FAQ, section “Do I have to pay impact fees?”Confirms: The City gives an under-750-square-foot exemption but directs larger-ADU impact-fee confirmation to Public Works. |
Inspection
Field inspections during construction.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU inspection, up to 499 square feet | $2,865 | Flat fee | FY 2025-26 Fee Schedule D — Building FeesLocation: Schedule D, PDF page 25, ADU Inspection Fees — up to 499 sq. ft.Confirms: The effective City schedule lists $2,865 for this ADU inspection band. |
| ADU inspection, 500–999 square feet | $4,010 | Flat fee | FY 2025-26 Fee Schedule D — Building FeesLocation: Schedule D, PDF page 25, ADU Inspection Fees — 500–999 sq. ft.Confirms: The effective City schedule lists $4,010 for this ADU inspection band. |
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 Cupertino before you commit money.
City reference pages for verification
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