Washington · HVAC
Ductwork Replacement cost in Washington
Statewide pricing, permit posture and inspection sequence for ductwork replacement in Washington. Your city or county issues the actual permit — use the local links below to confirm fees.
Verified August 2026
Ductwork Replacement cost in Washington
$2,900 – $13,900
Most Washington homeowners pay around $6,300, or $300–$700 per supply run. Permit fees typically add $105–$370.
Permit: Yes. Washington State Residential Code, based on the IRC, plus the State Energy Code
Cost breakdown
| Budget scope | $2,900 |
|---|---|
| Typical project | $6,300 |
| Premium / complex | $13,900 |
| per supply run | $300 – $700 |
| Permit fees | $105 – $370 |
| vs national baseline | +16% |
| Timeline | 1-3 days of work, 1-3 weeks including permitting |
What is different about ductwork replacement in Washington
The State Energy Code is among the most demanding in the country and is pushing heat pumps to the default HVAC replacement, which changes both cost and rebate eligibility.
Owner-builder: Homeowner permits allowed on owner-occupied property. Ductwork Replacement generally requires a licensed contractor to pull the permit, even where owner-builder status is available.
Inspections
- Duct rough-in
- Duct leakage test
- Final mechanical inspection
What drives the price
- Number of supply and return runs
- Flex duct versus rigid sheet metal
- Attic access and clearance
- Return air sizing corrections
- Removal of contaminated duct board
Frequently asked questions
Does duct replacement need a permit in Florida?
Yes. Replacing a duct system requires a mechanical permit and a duct leakage test in most Florida jurisdictions, because duct leakage is regulated under the energy code.
Sources
Sources & verification
Last verified August 2026. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing — they are not quotes. Permit rules change; confirm with the building department before starting work.