Fresno County, CA Accessory Structures: ADU Impact Fees (2026)
Key Facts
- Fee waiver threshold
- Under 750 sq ft: no impact fees
- 750 sq ft or larger
- Prorated fee formula applies
- Excluded from waiver
- Water/sewer connection and capacity charges
- Governing section
- Zoning Ordinance § 834.4.030(B)(6)(i)
Summary
Fresno County charges no impact fees, including school fees, on an accessory dwelling unit under 750 square feet; larger ADUs pay a fee prorated to their square footage against the primary home rather than the full new-dwelling rate.
i. Impact Fees. No impact fees (including school fees) shall be charged to
an Accessory Dwelling Unit that is less than 750 square feet in size. Any
impact fee charged to an Accessory Dwelling Unit 750 square feet or
greater shall be charged proportionately in relation to the square footage
of the primary dwelling unit (e.g. the floor area of the primary dwelling,
divided by the floor area of the Accessory Dwelling Unit, times the
typical fee amount charged for a new dwelling. For the purposes of this
paragraph, impact fees do not include any connection fee or capacity
charge for water or sewer service.
Additional Standards Applicable to Attached and Detached Accessory Dwelling Units. The following standards apply only to attached and detached Accessory Dwelling Units.
a. Size.
Final Zoning Ordinance 4-9 March 2026
Full Breakdown
The fee rule sits in the same general-standards subsection as the sprinkler and rental provisions. 030(B)(6)(i) states: "Impact Fees. No impact fees (including school fees) shall be charged to an Accessory Dwelling Unit that is less than 750 square feet in size. " The section further clarifies that "impact fees do not include any connection fee or capacity charge for water or sewer service," meaning utility connection and capacity charges still apply regardless of the ADU's size. 030(B)(7)(a), a builder who keeps a unit under the 750-square-foot line avoids school and other development impact fees entirely, while a larger unit is billed on a proportional formula tied to the primary home's floor area rather than the standard new-dwelling fee schedule.
Violations & Fines
This is a fee-assessment standard rather than a use restriction; a permit applicant who is incorrectly charged full impact fees on a sub-750-square-foot ADU can challenge the assessment with the Department of Public Works and Planning citing § 834.4.030(B)(6)(i) directly.
Frequently Asked Questions
Does Fresno County charge school fees on an ADU?
How is the fee calculated for a larger ADU?
Are water and sewer connection charges waived too?
Sources & Official References
Other rules in Fresno County
California rules heatmap·Compare Fresno County to another location·View the California accessory structures overview
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