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Homeowner rules in Fairfax County, VA

A person last checked these rules on October 20, 2026. This is guidance only, so confirm with Fairfax County before you build.

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.

Permits and building

  • Do I need a permit?Virginia's statewide code sets Fairfax's building-permit exemptions: sheds up to 256 sq ft, fences of any height (except pool barriers), masonry walls up to 6 ft, retaining walls holding back less than 3 ft, small shallow pools and like-for-like electric HVAC swaps. Every deck needs a permit. Zoning and grading rules still apply.
  • Solar panelsRoof-mounted solar may rise 5 ft above the district height limit. Ground mounts and solar canopies follow the accessory structure setbacks. Building and electrical permits are required, and an HOA can't ban panels unless its recorded declaration already did.
  • AC units, heat pumps and generatorsAC units, heat pumps, pool pumps and generators may extend 5 ft into a setback but must stay at least 5 ft from every lot line, and each unit must be 10 ft wide or less. The noise ordinance covers all of them.
  • EV charging at homeLevel 1 and Level 2 chargers are allowed at houses for residents and guests. A Level 2 install needs an electrical permit.
  • Construction hours and noiseConstruction is generally allowed 7 a.m. to 9 p.m. on weekdays and 9 a.m. to 9 p.m. on weekends and holidays, with a 90 dB limit at residential property lines.
  • Energy codes, green building and upkeepHouses follow the Virginia USBC (2021 edition), including its energy provisions. Code Compliance handles upkeep and occupancy problems in existing homes.

Yard and structures

  • Fences and wallsFences and walls are limited to 4 ft in a front yard and 7 ft in side and rear yards. Up to 7 ft anywhere on lots of 2 acres or more in R-A, R-C, R-E and R-1. No building permit is needed for a fence unless it is a pool barrier.
  • Retaining wallsA retaining wall holding back less than 3 ft of soil needs no building permit. Taller walls or walls with a surcharge do. Fairfax counts walls toward fence height limits, and marine clay or grading over 2,500 sq ft add engineering and plan review.
  • Corner sight trianglesOn a corner lot, keep a triangle 30 ft along each street line clear between 3.5 ft and 10 ft above street grade. Fences, walls, shrubs and low branches all count.
  • Decks, porches and roof decksEvery deck needs a building permit in Virginia. A deck may extend into setbacks: an open deck 4 ft or lower, 20 ft into the rear setback and 5 ft into a side setback, never closer than 5 ft to the line.
  • Sheds and garagesA shed up to 8.5 ft tall can sit anywhere in a side or rear yard. 8.5 to 12 ft needs 5 ft from the lines. Taller needs the district side setback and a rear setback equal to its height. Accessory buildings are capped at 20 ft tall and 50% of the house's floor area on lots of 36,000 sq ft or less.
  • Pools and hot tubsA pool is a freestanding accessory structure: allowed in side and rear yards, counted toward the 30% rear setback coverage cap with its decking, and needing a building permit unless it's 150 sq ft or less and under 24 in deep.
  • Exterior lighting and light trespassFairfax's outdoor lighting rules apply to houses with some relief: small fixtures (1,500 lumens or less) skip the full cut-off rule, and motion lights up to 4,000 lumens are exempt if they shut off within 5 minutes and stay aimed on your property. No fixture may cause disability glare.
  • Driveways and front-yard parkingFront-yard paving at a single-family house on a lot of 36,000 sq ft or less is capped at 25% of the front yard in R-1 and R-2 and 30% in R-3 and R-4. A two-car pad up to 18 by 25 ft is always allowed.
  • Pergolas, play sets and carportsPergolas, gazebos, play sets and treehouses follow the freestanding accessory structure rules by height. Two small trellises may stand in the front setback. Play equipment counts toward the rear setback coverage cap.

Land and environment

  • TreesFairfax's tree conservation rules (Chapter 122) attach to development plans, not to an ordinary house lot. In a Resource Protection Area, removing vegetation needs county approval. Check any proffers or plan conditions on your subdivision.
  • Floodplains, RPAs, wetlands and stormwaterResource Protection Areas (the 100 ft buffers along streams), floodplains and grading are the big three. SetbackIQ checks the county's RPA map for your lot.
  • Steep slopes and problem soilsFairfax maps marine clay (Marumsco soils) and other shrink-swell soils. On those soils the Problem Soils Ordinance requires a geotechnical report for new construction and grading, with footings at least 4 ft deep.
  • Historic districtsIn a Historic Overlay District, exterior changes need Architectural Review Board approval before permits issue. SetbackIQ checks the county's HOD map.
  • Grading, easements and demolitionUp to 2,500 sq ft of disturbance (and 18 in of cut or fill) needs no grading plan. Up to 5,000 sq ft for a house addition, accessory structure or demolition can go on a certified plat with silt controls. More needs an approved grading plan.

Living and use

  • RVs, boats and trailers at homeYou may park your own RV or travel trailer on the lot where you live. It isn't a commercial vehicle. In the front yard it must sit on the surfaced area, which is capped at 25% of the front yard in R-1 and R-2 and 30% in R-3 and R-4. One commercial vehicle is allowed, up to 21 ft long, 8 ft tall and 8.5 ft wide. Equipment trailers aren't allowed.
  • Chickens, bees and urban farmingChickens and other poultry are allowed only on lots of 2 acres or more, at one bird unit (32 chickens) per acre. Roosters only on working farms. Up to four beehives are allowed on any lot.
  • Home businessesMost home businesses need a $140 administrative permit: up to 400 sq ft, one non-resident employee at a single-family house, and no customers except small instruction (4 at a time, 8 a day). Bigger operations need a BZA special permit.
  • Family child care homesBy right you may care for up to 7 children (plus your own) in a single-family detached house, or 5 in a townhouse or apartment, with one non-resident helper. Up to 12 needs a BZA special permit. A state license or county permit is also required.
  • Occupancy limitsA household may be any number of relatives, or up to four unrelated people. A family may add up to two roomers.
  • Short-term rentalsYou need a short-term lodging permit, must live in the home at least 185 days a year, and may rent no more than 60 nights a year to no more than six adults at a time.