Accessory Structures in Fairfax County, VA (2026)
4 rules for unincorporated Fairfax County, Virginia.
Verified from official government sources
ADU Rules
An accessory living unit in Fairfax County needs a recorded administrative permit, issued for an initial two-year term and renewable in five-year increments by the Zoning Administrator.
Fairfax County ADU Permit Term Rules
Some RestrictionsFairfax County, VA, Zoning Ordinance § 4102.7.B(12)-(13)
Before occupancy of the accessory living unit, the owner must record a copy of the administrative permit among the land records of Fairfax County. The permit must contain a description of the property and must be indexed in the Grantor Index in the name of the property owner(s). (13) An administrative permit for an accesso...
ADU Owner Occupancy
Fairfax County zoning requires that either the accessory living unit or the main house be owner-occupied, preventing owners from renting out both the ADU and the principal dwelling to tenants at the same time.
Fairfax County ADU Owner-Occupancy Rule
Some RestrictionsFairfax County, VA, Zoning Ordinance § 4102.7.B(6)
Either the accessory living unit or the principal dwelling unit must be owner-occupied. (7) The accessory living unit may be occupied by no more than two people. https://online.encodeplus.com/regs/fairfaxcounty-va/doc-viewer.aspx#secid--1 240/545 8/18/26, 9:54 PM Document Viewer | Zoning Ordinance (8) The principal single-fam...
Shed & Carport Rules
Fairfax County caps freestanding sheds on typical lots at 20 feet tall and sets side/rear setbacks that scale with height under the zoning ordinance's accessory-structure standards.
Fairfax County Shed Size and Setback Rules
Some RestrictionsFairfax County, VA, Zoning Ordinance § 4102.7.A(6)(b)-(c)
(c) Maximum Height On lots 36,000 square feet in size or less, when accessory to a single-family dwelling, the height of an enclosed freestanding accessory structure may not exceed 20 feet; however, the BZA may approve a special permit for an increase in height... 2. If the structure is between eight and one-half feet in height and 12 feet in height, it must be located a minimum of five feet fr...
Tiny Homes
Fairfax County's Zoning Ordinance classifies a tiny house as a recreational vehicle or travel trailer unless it sits on a permanent foundation and is meant for continuous occupancy, in which case it counts as a single-family dwelling.
Fairfax County Tiny House Classification Rule
Some RestrictionsFairfax County, VA, Zoning Ordinance § 9102, definition of "Tiny House"
Tiny House: A small structure constructed on a frame and capable of being transported on its own wheels. For the purposes of this Ordinance, if a tiny house includes a permanent foundation and is intended for continuous occupancy, it is considered a single-family detached dwelling and must meet the USBC. Otherwise, a tiny house is considered to be a recreational vehicle or travel trailer.
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