ADU permit cost and fee breakdown in Lafayette, California
GetYourPermit’s researched permit-fee range for a detached accessory dwelling unit in Lafayette, 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
$7,700 – $17,550
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
$11,650
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$700
Shown only where the City bills Planning or zoning review as a separate fee.
- Building plan check$1,250 – $2,850
The Building Division’s review of the drawings; part of the Building Permit process.
- Building permit issuance$1,600 – $3,600
The permit issuance charge; where plan check is bundled, the combined amount is carried here.
- Separate trade permits$600 – $1,400
Shown separately only where electrical, plumbing, or mechanical permits are billed outside a combination permit.
- School district fees$2,000 – $3,200
Possible school-district developer fees based on current thresholds and scope.
- Utility fees$500 – $3,500
Possible water, sewer, electrical, meter, or capacity-related charges.
- Processing, inspection & records$250 – $500
Fixed processing, inspection, records, and administrative charges.
- Surcharges, taxes & state fees$800 – $1,800
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 and grading permit surcharge | 50% formula | Formula | Planning & Development Fees Effective July 1, 2026Location: Planning & Development Fees, page 1, Account 011-424-530Confirms: The City schedule states this County-labeled building and grading surcharge is 50% of the permit fee. |
Impact fees
Development impact fees. Prohibited for ADUs of 750 sq ft or less.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| City ADU development impact fees | 50% formula | Formula | Planning & Development Fees Effective July 1, 2026Location: Planning & Development Fees, page 3, ADU rows and asterisk footnote; City ADU page, fee-reduction sectionConfirms: The City gives both the threshold/proportional formula and a time-limited 50% new-ADU impact-fee reduction, while preserving separate listed components. |
Surcharges, taxes & state fees
Percentage surcharges, construction taxes, and State-mandated charges.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU Zoning Administrator fee | $700 | Flat fee | Planning & Development Fees Effective July 1, 2026Location: Planning & Development Fees, page 1, Account 011-424-790Confirms: The current City schedule lists the Accessory Dwelling Unit (Zoning Administrator) fee as $700. |
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 Lafayette before you commit money.
City reference pages for verification
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