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AC units, heat pumps and generators in Fairfax County, VA

AC 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.

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

The details

  • Setback rule: up to 5 ft into a minimum setback, never within 5 ft of a lot line, 10 ft wide maximum.High confidence
  • Replacing an electric heat pump or AC unit needs no building permit in Virginia. A new system or anything gas-fired does.High confidence
  • Heat pumps, AC units, pool pumps and generators are listed sources under the Chapter 108.1 noise ordinance. Code Compliance measures complaints at the property line.High confidence

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Common questions

Where can outdoor mechanical equipment go in Fairfax County?
AC 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.

Sources

  1. Fairfax County Zoning Ordinance § 5100.2.D, setback regulations (corner lots, sight distance, permitted extensions). Checked 2026-10-21
    [Sight distance] Points must be 30 feet from the property lines extended... Sight distance must be maintained between two horizontal planes, one of which is three and one-half feet, and the other ten feet above the established grade... [Extensions] heating,…
  2. Virginia USBC, 13VAC5-63-80 Section 108.2 (pools, mechanical, electrical and flood-area items). Checked 2026-10-21
    8. Swimming pools that have a surface area not greater than 150 square feet and are less than 24 inches deep... 14.4 Replacement of mechanical appliances provided the equipment is not fueled by gas or oil in Group R-2 where serving a single-family dwelling …
  3. Fairfax County Zoning Administration, Noise Ordinance (Chapter 108.1). Checked 2026-10-21
    Construction activities are generally allowed between 7 a.m. - 9 p.m. Monday - Friday, and 9 a.m. - 9 p.m. on weekends and holidays, with noise restricted to 90 dB at property boundaries in residential areas... [The chart covers] heat pumps, air conditioner…

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.