Ductwork Replacement cost in Seattle, WA
Seattle, WA · updated August 2026
$7,100
Typical local cost
$3,300 – $15,900
Typical range
- per supply run
- $350 – $800
- Permit
- Yes
- Typical timeline
- 1-3 days of work
Installed, local pricing
$120 – $430 in fees
1-3 days of work, 1-3 weeks including permitting
Seattle runs +32% against the U.S. average · data confidence Medium · modeled estimate, not a quote
The modeled midpoint for Seattle is $7,100. The local adjustment for this trade is x1.323 — driven mainly by King County labor rates and 55% exposure to local code requirements.
Estimate your Seattle job
Priced with this market's cost index, so the calculator, the size table and the ranges on this page all agree.
Recommended size
5 tons
Round to the nearest half ton
- Cooling load
- 61,000 BTU/hr
- Typical equipment costInstalled, 14-17 SEER2
- $11,246 – $21,168
- Rule-of-thumb check
- 400 sq ft per ton
Priced for Seattle (local adjustment x1.323).
Estimates only. Local pricing, site conditions and code requirements change the real number.
Cost by project size
Generated from the same unit pricing the calculator uses.
| Project size | Estimated range |
|---|---|
| 8 supply run | $2,800 – $6,400 |
| 10 supply run | $3,500 – $8,000 |
| 13 supply run | $4,600 – $10,400 |
| 17 supply run | $6,000 – $13,600 |
| 22 supply run | $7,700 – $17,600 |
Based on Seattle pricing of $350–$800 per supply run.
Where the money goes
- Labor
- $3,200
- 43% of median
- Materials
- $3,900
- 53% of median
- Permit & fees
- $275
- 4% of median
Seattle project costs+32% vs U.S. average
Based on King County labor rates, local material logistics and permit-fee posture for this trade.
What the project looks like start to finish
Typical sequence for this scope. Timing varies with contractor backlog and plan-review queues.
01
Planning & quotes
Scope, material choice, contractor selection
02
Permit application
Filed with City of Seattle building department
03
Materials & staging
Order lead time on non-stock materials
04
Installation
1-3 days of work, 1-3 weeks including permitting
05
Inspection
Duct rough-in, Duct leakage test, Final mechanical inspection
06
Closeout
Final sign-off, warranty and documentation
Seattle labor intelligence
What the trade charges here, and how much of your price it is.
Loaded hourly rate
$112–$145
HVAC crews in King County · +34% vs U.S. ($95/hr)
Typical crew
2 × 1.5 days
On-site time for a typical ductwork job here.
Labor in the price
$3,200
45% of the median — the rest is material, disposal and permit.
Because labor is 45% of this job, Seattle wage levels move the price far more than material prices do. A quote well under this labor figure usually means a smaller crew, a longer schedule, or unlicensed help.
Basis: Hometriva labor model: national hvac crew rates adjusted by the King County labor factor (x1.338). · BLS Occupational Employment and Wage Statistics, Hometriva methodology
Why Seattle differs from the national average
The local delta, broken into dollars by driver.
Trade labor rates+$825
King County crews price 34% above the national average, and labor is 45% of this job.
Material and delivery+$450
Materials are nationally traded, so they move less — but delivery into this market runs 15% over baseline.
Code and inspection load+$375
Ductwork Replacement carries 55% exposure to local code requirements, and this jurisdiction's review load indexes at x1.13.
Permit fees+$75
Fees are paid to the jurisdiction, not the contractor, and are budgeted separately from the contract price.
Basis: Decomposition of the modeled Seattle median against the U.S. median for this scope. · City of Seattle building department, Hometriva methodology
Seattle vs Washington vs the U.S.
Change the inputs, see your number
The same local model, run against your job instead of the average one.
Simulated ductwork replacement in Seattle
$7,375
Likely range $3,575 – $16,175
Simulated from the same local model as the numbers above — it changes the inputs, not the pricing method.
What makes the number move
- 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
Who issues each permit
Tracked per discipline — the building permit issuer is not always the body that reviews electrical, plumbing, zoning or fire.
| Discipline | Issuing authority |
|---|---|
| building | City of Seattle building departmentModeled estimate |
| electrical | City of Seattle building departmentModeled estimate |
| mechanical | City of Seattle building departmentModeled estimate |
| plumbing | City of Seattle building departmentModeled estimate |
| zoning | City of Seattle building departmentModeled estimate |
| fire | City of Seattle building departmentModeled estimate |
Permit requirement in Seattle
Yes — a permit is required for ductwork replacement in Seattle, WA. The work must be inspected before it can be closed out, and a licensed contractor generally has to pull the permit.
- Permitting authority
- City of Seattle building departmentModeled estimate
- Permit fee
- Estimated allowance $120–$430Modeled from comparable fee schedules — not an official quoted fee.
Inspections
- Duct rough-in
- Duct leakage test
- Final mechanical inspection
Local conditions that change this job
Only the exposures that materially affect ductwork replacement.
Cooling load / heat exposure
Moderate44/100
Humidity
High70/100
SDCI review timelines, seismic detailing and energy-code requirements add meaningful cost and schedule to structural and envelope work.
Nearby market comparison
+ Had ductwork replacement done in Seattle? Add what you paid or were quoted
Reports are reviewed before they count, and nothing is published until at least 5 reports exist for a market. No name, email or address is collected.
How Hometriva estimates Seattle ductwork costs
Hometriva does not publish invented city prices. The Seattle estimate for ductwork replacement is produced by this chain, and every input is stored separately:
- National baseline$5,400
Typical U.S. cost for ductwork replacement on a single-family home.
- Local labor factorx1.338
Seattle-area trade labor rates, weighted at 45% of this job.
- Material factorx1.153
Material and delivery pricing into King County, weighted at 55%.
- Regulatory factorx1.128
Local code, product-approval and inspection load, applied at 55% for this project type.
- Applied multiplierx1.323
Blended Seattle adjustment specific to ductwork replacement.
- Permit component$120 – $430
Budgeted separately from the contract price because it is paid to the jurisdiction.
Because labor, material and regulatory factors are weighted per project, ductwork replacement in Seattle carries a different local adjustment than other trades in the same market.
Reviewed by
Hometriva Cost Data Desk
Maintains the unit-cost baselines, local adjustment factors and material pricing. Reviewed for ductwork replacement pricing in Seattle, WA.
- • National unit-cost baselines against current trade pricing
- • Local labor and materials factors for the market
- • Material installed-cost ranges and service life
Last reviewed August 2026 · Editorial standards · Report an error
Frequently asked questions
Do I need a permit for ductwork replacement in Seattle, WA?
In most jurisdictions this work is permitted and inspected. Requirements are set locally, so confirm the current application and inspection checklist with your building department before work starts.
How long does ductwork replacement take?
1-3 days of work, 1-3 weeks including permitting. Permit review and inspection scheduling are usually the largest source of variation.
What changes the price the most?
The largest cost drivers are number of supply and return runs; flex duct versus rigid sheet metal; attic access and clearance.
Sources
Sources & verification
- City of Seattle building department
- Seattle permit portal
- Washington State Building Code Council
- BLS Occupational Employment and Wage Statistics
Model vintage August 2026. The links above are the issuing agencies' own pages — we publish them so you can confirm the current rule yourself, not as evidence that each fact on this page was re-checked with them today. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing, not quotes. Permit rules change; confirm with the building department before starting work.