Yuba County, CA Accessory Structures: ADU Rules (2026)

Yuba County Development Code Section 11.32.030 governs accessory dwelling units in the unincorporated county (not Marysville, Wheatland, or Yuba City, which is in Sutter County). The code expressly implements state ADU law, citing California Government Code Section 65852.2 and 65852.22. ADUs are approved ministerially: the County 'shall issue a building permit within 60 calendar days from the date on which the County received a completed application.' A detached ADU 'shall not exceed 850 square feet for a one-bedroom unit or 1,200 square feet for an accessory dwelling unit that provides more than one bedroom,' with a four-foot minimum side yard and four-foot minimum rear yard setback and a 16-foot height limit for newly built units. An attached ADU is limited to 850 sq ft (one bedroom) or 1,000 sq ft (more bedrooms), and may not exceed 50 percent of the existing primary dwelling up to a maximum 1,200 sq ft increase; conversions of existing space have no minimum setback. The County, special district, or water corporation may not impose any impact fee on an ADU of less than 750 square feet; units under 500 sq ft are not subject to school impact fees. ADUs may be rented but not sold separately from the primary residence, and no ADU permitted on or after January 1, 2020 may be rented for terms under 30 days.