Fremont, CA Accessory Structures: ADU Impact Fees (2026)

California state law - Government Code 65852.2(f)(3) - prohibits Fremont from charging any impact fees on an ADU under 750 sq ft. This exempts the unit from Fremont's Capital Facilities Fee, Park Impact Fee, Traffic Impact Fee, and Fremont Unified School District (FUSD) school facility fees, as well as from any Public Art / Public Safety impact fees the city collects under its Master Fee Schedule. For ADUs 750 sq ft or larger, impact fees must be charged proportionally based on the ratio of ADU floor area to primary dwelling area, per Gov. Code 65852.2(f)(3)(B). Fremont's standard building permit and plan-check fees apply at any ADU size (typical range $4,000-$9,000 for a detached unit) and are based on valuation per the city's Master Fee Schedule. ACWD (Alameda County Water District) and Union Sanitary District capacity charges may apply but are also subject to the state ADU fee exemption when the unit is under 750 sq ft. FUSD school facility fees (currently around $4-$5 per sq ft of habitable area under Education Code 17620 and SB 50) are waived for sub-750 sq ft ADUs by state preemption. The Mitigation Fee Act (Gov. Code 66020) lets a homeowner protest impact fees within 90 days of payment if they believe a fee was charged in error.