Fairfax County's Land Development Services handles building permits for the large unincorporated portion of the county. Cities like Fairfax City, Falls Church, and independent towns like Vienna, Herndon, and Clifton have their own permit offices — confirm your jurisdiction before applying.
The shed threshold is 256 sq ft — the same as many Northern Virginia and North Carolina counties. All decks attached to the house require a permit under the Virginia Uniform Statewide Building Code. Fences up to 7 feet don't require a building permit in unincorporated Fairfax County, but fences over 7 feet require a special use permit or zoning variance.
Fairfax County Land Development Services is at 12055 Government Center Parkway, Fairfax, VA 22035. Phone: (703) 222-0801. The online permit portal is at fairfaxcounty.gov/LDS. Permit fees in Fairfax County are higher than most Virginia counties — shed permits typically $100–$250, deck permits $150–$400.
What Requires a Permit
Frequently Asked Questions
- Yes. A 16×16 shed is 256 square feet — exactly at Fairfax County's threshold. Fairfax's rule is 'over 256 sq ft,' so technically a 16×16 is at the limit. To be safe, treat it as requiring a permit if it's 256 sq ft or larger. A 14×18 shed (252 sq ft) is under the threshold and generally doesn't need a permit, though setback rules still apply.
- In most residential zones in unincorporated Fairfax County, accessory structures must be at least 5 feet from side and rear property lines, not in the front yard setback, and at least 6 feet from the primary structure. Some zones have stricter requirements. Use the Fairfax County iMAPS tool at fairfaxcounty.gov/maps to check your parcel's zoning and specific setback requirements.