How much does it cost to replace ductwork?

Replacing a home's ductwork typically costs $1,400–$9,500 installed, averaging around $4,200 for a typical single-family home. By length, that works out to roughly $10–$45 per linear foot — material choice and how accessible the ducts are (an open attic vs. a tight crawlspace) explain most of the spread.

How much ductwork does an average house have?

Most single-family homes run somewhere between 200 and 400 linear feet of ductwork total, depending on square footage and layout — a typical 2,000–2,500 sq ft home lands around 200–275 feet. Larger and multi-story homes need more.

What's the cheapest type of ductwork?

Flexible duct is the cheapest option and the most common choice for branch runs to individual rooms. Rigid options — fiberboard and especially sheet metal — cost more per foot but hold up longer and are typically used for main trunk lines.

Why does replacing ductwork in a crawlspace or attic cost more?

Tight crawlspaces and hot attics slow the crew down — there's less room to maneuver, and attic work in summer often has to happen early or late in the day. That extra labor time is the main reason ductwork replacement in these spaces commonly runs noticeably higher per foot than an easy-access basement or mechanical room.

Is it worth replacing ductwork when I replace my furnace or AC?

If your ducts are old, leaky, undersized, or were never sealed well, replacing them alongside a new furnace or AC lets the new equipment perform the way it's rated to — a leaky or mismatched duct system can undercut the efficiency gains of new equipment. It's not automatic, though; a contractor can assess duct condition and sealing before you commit to replacing them.

Ductwork replacement cost in Seattle

Ductwork replacement in Seattle costs about $1,650 to $11,200 (typically $5,000) — local prices run about 18% above the national average.

These figures adjust our national ductwork replacement range to Seattle's local cost level — see the method and sources below.

Low

$1,650

Typical

$5,000

High

$11,200

About $11.80 – $53.10 per linear foot of ductwork, installed

How we localized this

We start from our national ductwork replacement range of $1,400–$9,500 and adjust it for Seattle, where costs run about 18% above the national average. Seattle is one of the more expensive U.S. metros for home-improvement work. A cost-index comparison frames Seattle renovation pricing as about 28% above the national average, while the multiplier it actually applies to project estimates is 20% above; other local remodeling guides put the range as high as 25–50% above, largely citing tech-sector wage competition for skilled trades. Mortenson's quarterly index shows Seattle's recent cost growth running below the national pace, which points to a market absorbing pressure rather than one still accelerating — but the underlying level remains high. We apply about 18% above national, close to the more conservative of the cited multipliers. Materials are priced roughly nationally, so treat this as an approximation — your actual price depends on your home, contractor, and project specifics.

Seattle cost sources (2)

Seattle Home Improvement Costs (2026) — Cost to Renovate
Construction Cost Index for Seattle — Mortenson

Tech-sector wage competition pulls up pay for skilled trades across the metro, and strong, steady demand leaves many contractors with little scheduling downtime. The Seattle Department of Construction and Inspections (SDCI) processes permits online, but timelines vary widely — simple permits often clear in 2–4 weeks, while structural work or an accessory dwelling unit (ADU) can take 3–6 months. Seattle's wet climate makes roofing and decking material choices matter more than in drier regions; composite decking and metal roofing cost more upfront but hold up better against sustained rainfall than wood or standard asphalt. ADU construction is especially active here, driven by the region's housing shortage and comparatively permissive local rules.

Estimate your Seattle ductwork replacement

Estimate by duct length, material, and access. The estimate starts from our published per-linear-foot range.

Your area

Adjusts the estimate to local cost levels. Pick a metro or leave on national.

Ductwork length: 200 linear feet

Duct material

Access & location

Tight crawlspaces and hot attics slow the crew down the most.

Scope

Estimated cost for your options in Seattle

$2,400 – $10,600

Typical: $5,200

Adjusted for Seattle — costs there run about 18% above the national average.

How we got this

Starts from our published ductwork replacement range (per linear feet × 200), adjusted for:

Duct material: Flexible duct (standard, most common)×1
Access & location: Open attic, basement, or mechanical room×1
Scope: Replacing ducts in existing pathways×1
Area: Seattle×1.18

These figures are planning estimates compiled from public cost data on the dates shown — not quotes, bids, or guarantees. Real prices vary widely with your home, location, materials, permits, and contractor. Always get itemized written quotes from licensed local pros before budgeting or hiring.

What changes the price

Ductwork length — Raises cost
Ductwork is priced largely per linear foot; longer runs and bigger homes cost more in total.
Material — Raises cost
Flexible duct is the cheapest and most common choice for branch runs; rigid sheet metal, typically used for trunk lines, costs more per foot.
Access & location — Raises cost
Ductwork in an open attic or basement is straightforward to reach; crawlspaces and other tight spaces slow the work and raise cost.
Adding ducts with no existing pathway — Raises cost
Running new duct through finished walls, floors, or ceilings that never had ductwork costs more than replacing ducts along an existing route.
Insulation — Raises cost
Insulated duct costs more than non-insulated, but cuts energy loss — uninsulated ducts running through unconditioned space can waste 10–15% of heating and cooling energy.
Asbestos or mold remediation — Raises cost
Older homes sometimes need abatement before old ductwork can be removed, which adds significantly to the job.

Get real quotes for your Seattle ductwork replacement

Our ranges are for planning. The only way to know your real price is itemized quotes from licensed local pros — always get at least three before you hire.

Tip: search for licensed, insured Seattle ductwork replacement contractors in your area, check reviews and references, and compare written itemized bids — not just bottom-line numbers.

Ductwork replacement cost — FAQ

How much does it cost to replace ductwork?: Replacing a home's ductwork typically costs $1,400–$9,500 installed, averaging around $4,200 for a typical single-family home. By length, that works out to roughly $10–$45 per linear foot — material choice and how accessible the ducts are (an open attic vs. a tight crawlspace) explain most of the spread.
How much ductwork does an average house have?: Most single-family homes run somewhere between 200 and 400 linear feet of ductwork total, depending on square footage and layout — a typical 2,000–2,500 sq ft home lands around 200–275 feet. Larger and multi-story homes need more.
What's the cheapest type of ductwork?: Flexible duct is the cheapest option and the most common choice for branch runs to individual rooms. Rigid options — fiberboard and especially sheet metal — cost more per foot but hold up longer and are typically used for main trunk lines.
Why does replacing ductwork in a crawlspace or attic cost more?: Tight crawlspaces and hot attics slow the crew down — there's less room to maneuver, and attic work in summer often has to happen early or late in the day. That extra labor time is the main reason ductwork replacement in these spaces commonly runs noticeably higher per foot than an easy-access basement or mechanical room.
Is it worth replacing ductwork when I replace my furnace or AC?: If your ducts are old, leaky, undersized, or were never sealed well, replacing them alongside a new furnace or AC lets the new equipment perform the way it's rated to — a leaky or mismatched duct system can undercut the efficiency gains of new equipment. It's not automatic, though; a contractor can assess duct condition and sealing before you commit to replacing them.

Cost data compiled July 26, 2026.

Sources (5)

How Much Does Duct Replacement Cost? [2026 Data] — Angi
How Much Does It Cost to Install or Replace Ductwork? (2026) — HomeGuide
How Much Does Air Duct Replacement Cost? (2026) — This Old House
How Much Does Ductwork Installation Cost in 2025? — HomeAdvisor
How Much Does It Cost to Install Ductwork? — Fixr

Ranges synthesize several public 2026 cost guides into a low–typical–high band rather than reproducing any single source's table. This models a full duct-system replacement along existing routes — a small single-run patch job or a first-time retrofit with no prior ductwork can fall outside this range on the low or high end, respectively. Metro-level breakdowns are coming as we verify local data.

Compare other locations

See all Seattle HVAC costs on the Seattle HVAC page.

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