HVAC replacement in Loudoun County, VA

Loudoun has grown fast. The county estimates it had 62,160 housing units in 2000 and about 155,360 in 2026, so most homes here were built in the last 25 years, and many of their original heating and cooling systems are reaching replacement age.

Permits in Loudoun County

Loudoun County's Department of Building and Development issues residential trade permits, and each trade (mechanical, electrical, plumbing, gas) needs its own permit. The county's mechanical permit application covers air conditioners, heat pumps and furnaces.

Contractors working in Loudoun need a Virginia contractor license and a Loudoun County business license. Since October 1, 2025, some residential fuel-gas work also requires plan review.

The Town of Leesburg does not issue its own building permits: the county issues them for homes in Leesburg too.

Ask every contractor whether the permit is included in their price and who will schedule the inspection.

Utilities

• Electricity: Dominion Energy Virginia or NOVEC, depending on where you live.
• Natural gas: Washington Gas or Columbia Gas of Virginia, in the parts of the county that have gas service.

Your utility matters for rebates, and for whether a heat pump, gas furnace or dual-fuel system makes the most sense for your bills.

Rebates and tax credits (as of November 2026)

• Federal tax credit: the 25C energy efficient home improvement credit, which covered heat pumps, central air and furnaces, ended for equipment placed in service after December 31, 2025. Systems installed in 2026 don’t qualify.
• Virginia home energy rebates: the state’s federally funded HEAR and HOMES programs are not open yet. Virginia Energy says launch depends on federal approval, and plans call for up to $8,000 toward a heat pump for income-qualified households. Work started before launch may not qualify.
• Washington Gas: customers can save up to $800 through the Home Energy Savings Program. In Virginia, the work must be done by a contractor in the program’s network.
• Columbia Gas of Virginia: up to $500 for a gas furnace rated 90% AFUE or higher in an existing home heated mainly by gas, bought and installed in 2026. Apply within 120 days or by January 31, 2027, whichever comes first. Funds are first come, first served.
• Dominion Energy Virginia: no rebate is currently listed for central heat pumps or air conditioners. Dominion offers smart thermostat rewards and an income- and age-qualifying program.

Rebate terms change often. Confirm the current terms with the utility before you buy.

What replacement costs here

In real Northern Virginia quotes we’ve reviewed, a complete furnace and air conditioner or dual-fuel replacement ran from $12,576 to $21,594. See what drives the price, and why quotes for the same house differ.

Because so much of Loudoun was built in the same two decades, whole neighborhoods tend to need replacements at about the same time. It's worth planning before the original system fails in a heat wave.

Before you sign

• Check the contractor’s Virginia license on the DPOR license lookup. HVAC work falls under the HVA specialty, and gas work under the GFC specialty.
• Make sure the size comes from a Manual J load calculation, not from the old unit.
• Get exact model numbers, and confirm whether the refrigerant lines and return ducts are included.
• Confirm the permit, inspection and labor warranty are in writing.

How 1Stop helps in Loudoun County

1Stop is an independent service based in Ashburn. We don’t install systems or work for any contractor. A Comfort Consultant visits your home, runs a Manual J load calculation and writes one scope of work. Licensed, insured local contractors bid on that same scope, and you compare every bid side by side. It’s free for homeowners. See a sample comparison.