Accessory Structures in Placer County, CA (2026)
6 county-level rules, plus city-specific rules for 1 city in Placer County, California.
Verified from official government sources
ADU Rules
In unincorporated Placer County, residential parcels may have one primary dwelling, one accessory dwelling unit (ADU) and one junior ADU. Detached ADUs may reach 1,200 sq ft; attached ADUs up to 50% of the primary dwelling. There is no minimum parcel size, setbacks are 4 ft from side and rear lot lines, and parking is capped at one space per ADU.
Placer County ADU Rules
Some RestrictionsPlacer County Code § 17.56.200 (Accessory and junior accessory dwelling units)
One ADU and one Junior ADU are allowed per parcel in addition to the primary dwelling. Detached ADUs may be up to 1,200 sq. ft. The minimum required setback for a new construction ADU on a single-family property is 4 feet from the rear and interior side property lines.
ADU Impact Fees
Placer County waives building permit fees and road and park impact fees for accessory dwelling units of 750 square feet or larger if the owner voluntarily deed-restricts the unit for affordability. Verification of the deed restriction must be filed with the county before the exemption applies.
Placer County ADU Impact Fee Exemption
Light RestrictionsPlacer County Code § 15.65.110(B)
Deed Restricted Accessory Dwelling Units. In the case where a property owner or developer voluntarily opts to deed-restrict an accessory dwelling unit that is 750 square feet or greater in size for affordability, said unit shall be exempt from payment of building permit fees and those fees identified in Placer County Code Chapter 15, Articles 15.28 (County Road Network) and 15.34 (Parks and Rec...
ADU Rental Restrictions
Accessory dwelling units permitted in unincorporated Placer County after June 9, 2020 cannot be rented as short-term vacation rentals. Placer County Code § 9.42.090(A)(2) also bars short-term renting of tiny homes and mobile or manufactured home units, closing entire categories of housing stock out of the county's short-term rental program regardless of location or unit-cap availability.
Placer County ADU Short-Term Rental Ban
Significant RestrictionsPlacer County Code § 9.42.090(A)(2)
2. Types of Units. Short-term rental of tiny homes or mobile or manufactured home units is prohibited. If the unit is an accessory dwelling unit permitted after June 9, 2020, it may not be short-term rented.
Shed & Carport Rules
In unincorporated Placer County, a one-story detached accessory building used as a tool shed, storage shed or playhouse does not require a building permit if its floor area does not exceed 120 square feet. Even exempt sheds must meet zoning setbacks measured under the Placer County Zoning Ordinance, and any electrical, mechanical or plumbing work requires a permit.
Placer County Shed Rules
Some RestrictionsPlacer County FAQ (Building Services) and Placer County Code § 17.56.020
One-story detached accessory buildings used as tool and storage sheds, playhouses, and similar uses, provided the floor area does not exceed 120 square feet, do not require a Building Permit. Contact the Planning Division for required setbacks from property lines for such structures.
Garage Conversions
Converting a garage into living space in unincorporated Placer County requires a building permit and must meet building, energy and zoning standards. A garage converted into an accessory dwelling unit is a state-favored ADU pathway under Placer County Code 17.56.200; conversion ADUs are exempt from added parking. Replacement of any displaced required parking may apply for non-ADU conversions.
Placer County Garage Conversions
Some RestrictionsPlacer County Code § 17.56.200 (consistent with CA Gov. Code § 65852.2)
When a garage, carport, or covered parking structure is converted to an accessory dwelling unit, the local agency shall not require that those off-street parking spaces be replaced. Additional parking is not required for junior ADUs or ADUs that are converted from a garage, carport or other covered parking space.
Tiny Homes
Placer County regulates tiny houses on wheels through a dedicated zoning section: they need zoning clearance, DMV or HCD registration, and a residential (not RV) look, and must sit at least four feet from a lot line and 10 feet from other structures.
Placer County Moveable Tiny House Rules
Some RestrictionsPlacer County Code § 17.56.400(C)(1)-(4)
17.56.400. Moveable tiny houses. When allowed, by Section 17.06.030 et seq. (Allowable land uses and permit requirements), in the zone applicable to a site, moveable tiny houses are subject to the requirements of this section. 1. Zoning Clearance. A moveable tiny house shall be required to undergo zoning clearance to demonstrate compliance with all standards described below, and is subject to a...
Accessory Structures by City in Placer County
1 cities in Placer County have their own accessory structures rules. Each link goes to that city's dedicated page with code citations.
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