Santa Barbara County, CA Accessory Structures: ADU Impact Fees (2026)
Key Facts
- Exemption threshold
- ADU under 750 square feet
- JADU status
- Fully exempt regardless of size
- Fee basis
- Proportional to principal dwelling square footage
- State law implemented
- Gov't Code §§ 66310-66342
- Fee rate set
- At time of payment, not application
- Permit timeline
- Ministerial review within 60 days
Summary
Santa Barbara County waives development impact mitigation fees for any accessory dwelling unit under 750 square feet and for junior accessory dwelling units entirely, under LUDC Section 35.42.015.D.4. Larger ADUs still owe fees, charged proportionately to the floor area of the principal dwelling, under whatever fee resolution is in effect when the fee is paid.
4.Development impact mitigation fees. Except as provided in Subsection 4.a, below, the applicant shall pay development impact mitigation fees in compliance with ordinances and/or resolutions in effect at the time the fees are paid. The amount of the required fee shall be determined by adopted fee resolutions and ordinances and applicable law in effect when paid, provided that the fee is charged proportionately in relation to the square footage of the principal dwelling.a.The applicant shall not be required to pay development impact mitigation fees for an accessory dwelling unit of less than 750 square feet or a junior accessory dwelling unit.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 44 Update 1).
Full Breakdown
The exemption sits inside Santa Barbara County's accessory dwelling unit standards, adopted to implement California Government Code Sections 66310 through 66342. 4, an applicant for an ADU or JADU normally owes development impact mitigation fees in compliance with whatever fee resolutions and ordinances the Board of Supervisors has in effect on the date the fees are actually paid, not the date the application was filed. Where fees do apply, the amount must be charged proportionately in relation to the square footage of the principal dwelling on the lot, not a flat per-unit rate.
a then carves out the exemption: an ADU under 750 square feet, and a junior accessory dwelling unit of any size, owes no development impact mitigation fees at all. 6, so every legally built JADU in the unincorporated county automatically qualifies. A detached or attached ADU of 750 square feet or more loses the exemption and is billed on the same proportional basis as the principal dwelling. 2. 4 is set separately by Board resolution, the dollar amount changes over time; the 750-square-foot exemption line itself is fixed in the LUDC text.
Violations & Fines
There is no separate infraction for the fee itself; the consequence of a fee dispute is administrative, not punitive. The Building Official will not finalize the Building Permit for an ADU of 750 square feet or more until the applicable development impact mitigation fees, calculated under the fee resolution then in effect, have been paid in full to the Department of Planning and Development.
Frequently Asked Questions
Do I owe impact fees for a small ADU in unincorporated Santa Barbara County?
How is the fee calculated for a larger ADU?
Are junior accessory dwelling units ever charged impact fees?
Sources & Official References
Other rules in Santa Barbara County
California rules heatmap·Compare Santa Barbara County to another location·View the California accessory structures overview
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