Occupancy limits in Fairfax County, VA
A household may be any number of relatives, or up to four unrelated people. A family may add up to two roomers.
A person last checked these rules on October 20, 2026. This is guidance only, so confirm with Fairfax County before you build.
The details
- No more than four people not related by blood or marriage may live together as one household.High confidence
- With an accessory living unit, the ALU holds 2 people and the house the same limits.High confidence
- A second kitchen doesn't automatically make a second unit. Owners can get a second-kitchen certification.High confidence
Check a project at your address
SetbackIQ reads the zoning, flood zone, historic district, and environmental maps for your lot. Then it applies these rules.
Common questions
- How many unrelated people may share a house in Fairfax County?
- A household may be any number of relatives, or up to four unrelated people. A family may add up to two roomers.
Sources
- Fairfax County Code Compliance, How many people can live in a home?. Checked 2026-10-21
No more than four persons not related by blood or marriage functioning as a single household [§ 4102.3.A]... no more than one family, plus two renters, may live together as a single household... The presence of a second kitchen in a home does not automatica…
- Fairfax County Zoning Ordinance § 4102.7.B, accessory living unit. Checked 2026-10-20
An accessory living unit must be wholly contained within the structure of a single-family detached dwelling unit... must not exceed: (a) 800 square feet of gross floor area or 40% of the gross floor area of the principal dwelling, whichever is less; or (b) …
Disclaimer: This is general information, not legal or professional advice for any one property. Codes change. SetbackIQ is not a zoning determination, a permit, or a survey, and it does not replace an architect, engineer, or lawyer. Confirm with your building and zoning offices before you build, buy, or sign a contract.