Fairfax County, VA Accessory Structures: ADU Rules (2026)
ADU rules in Fairfax County, VA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Permit type
- Administrative permit
- Initial term
- 2 years
- Renewal
- Up to 5 years each
- Recording
- Must record in land records
Summary
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.
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 accessory living unit may be issued to the owner for an initial period of
two years from the date of approval. An administrative permit may be extended by the Zoning Administrator for succeeding periods of up to five years based on the applicant's record of compliance with the standards in this subsection.
(14) If the standards above are no longer being met, the accessory living unit may not be occupied as a
dwelling unit and the property must meet the occupancy limitations of a single-family dwelling in accordance with subsection 4102.3.A. This standard does not require the removal of any kitchen or other facilities.
Standards when permitted by special permit:
(15) The accessory living unit must conform to all applicable standards for an administrative permit above,
Official source re-checked September 7, 2026: no newer edition of the code had been published.
Full Breakdown
Fairfax County issues accessory living unit approvals as administrative permits rather than building permits alone. Before anyone moves into the ADU, the owner must record a copy of the permit among the county's land records, indexed in the Grantor Index under the property owner's name. The initial permit term is two years from approval; the Zoning Administrator may then extend it for renewal periods of up to five years each, based on the owner's compliance record with the ADU standards in subsection 4102.7.B.
Violations & Fines
Occupying an ADU without a recorded administrative permit, or after the permit term lapses without renewal, is a zoning violation and can void the ADU's dwelling-unit status.
Frequently Asked Questions
How long does a Fairfax County ADU permit last?
Do I need to record the ADU permit?
Sources & Official References
Other rules in Fairfax County
How Fairfax County compares: Easiest Cities to Build an ADU·Compare Fairfax County to another location·View the Virginia accessory structures overview
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