How Much Does Ductwork Cost to Install or Replace in 2026?
National ranges, materials + labor · Pricing data updated · Reviewed annually
Replacing all the ductwork in a typical ~1,800 sq ft home costs $2,250 to $5,250, around $3,750 for most jobs, reusing the existing furnace and AC. Smaller jobs cost far less: adding one or two runs to a finished basement runs $800 to $1,700, and sealing and insulating attic ducts $1,900 to $4,250.
What sets the price is the scope of the job, where the ducts run (basement, attic, crawlspace, or inside finished walls), and the duct material. The tables below price duct work by the foot, by the run, and by the project, and the estimator combines them. Size the runs first with the free duct size calculator. Replacing the furnace or AC too? See HVAC replacement cost; going ductless instead? See mini-split installation cost.
Ductwork cost by project
Installed ranges at the national average, including a permit. Equipment is not included. Each project assumes its usual access — the basement add assumes an exposed trunk, the whole-home replacement assumes an attic, and the no-ducts retrofit assumes cutting into finished walls.
| Project | Installed | Likely |
|---|---|---|
| Add 1–2 runs to a finished basementTap an exposed trunk; includes the ceiling patch | $800 – $1,700 | $1,200 |
| Extend ducts to an addition~400 sq ft: 2–3 supplies, 1 return, short trunk extension, permit | $1,700 – $3,250 | $2,500 |
| Seal + insulate attic ductsMastic/foil-tape sealing, R-8 wrap, and a leakage test | $1,900 – $4,250 | $3,000 |
| Replace one trunk + branches~25 ft of trunk and 5–7 branch runs (~100–120 ft) | $2,000 – $4,500 | $3,250 |
| Replace all ductwork~1,800 sq ft home, ducts in an attic, equipment reused | $2,250 – $5,250 | $3,750 |
| New ducts in a home that has none~1,800 sq ft, ~200 ft run through finished walls and ceilings | $6,000 – $12,500 | $9,250 |
Ductwork cost per linear foot
Per-foot rates are useful for checking a bid line by line, but published rates disagree by more than 100% — mostly because sources assume very different amounts of duct per home. A typical home has roughly 0.08–0.14 ft of trunk and branch duct per sq ft of floor area, or about 140–250 ft for 1,800 sq ft. Insulation adds about $2–$4 per foot where it is not already built in.
| Duct material | Installed / ft | Material only / ft |
|---|---|---|
| Flex duct, insulatedMost common for branch runs in attics | $8 – $25 | $2 – $4 |
| Flex duct, uninsulatedOnly inside conditioned space | $7 – $22 | $1 – $3 |
| Duct board (fiberglass) | $12 – $25 | $4 – $7 |
| Sheet metal, rectangularSite-built trunks; steel-price sensitive | $20 – $60 | $7 – $15 |
| Round / spiral galvanized | $10 – $35 | — |
Cost to add or move a duct run
| Job | Typical range | Notes |
|---|---|---|
| Add a supply run (basement or attic access) | $250 – $650 | Run, boot, and register |
| Add a supply run in a finished space | $600 – $1,800 | Includes drywall cut and primer-ready patch |
| Add a return-air run with grille | $250 – $750 | Add a patch for finished walls |
| Move a register | $200 – $700 | Reroute ~5–10 ft and cap the old opening |
| Patch per wall or ceiling opening | $200 – $800 | Primer-ready; paint not included |
Adding runs to a system sized for less can starve the rooms already on it. Check the new run sizes with the duct size calculator and the heating and cooling load with the Manual J calculator.
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Add-on costs
Priced against a whole-home replacement at the national average. Access and story count scale with the size of the job; the rest are flat per-job costs.
| Add-on | What's involved | Adds |
|---|---|---|
| Ducts in a crawlspace | Tight, low access instead of an attic | +$500 – $2,250 |
| Runs to an upper floor | Ducts routed between floors through chases or closets | +$250 – $1,750 |
| Permit | Mechanical permit; some places require a leakage test on altered systems | +$0 – $500 |
| Duct leakage test | Duct Blaster test before and/or after the work | +$250 – $500 |
| Manual D duct design | A room-by-room design so the new runs are sized right | +$250 – $500 |
| One more supply run | Run, boot, and register in an accessible basement or attic | +$250 – $500 |
| Add a return-air run | Return duct and grille — fixes stuffy closed-door rooms | +$250 – $750 |
| Seal accessible ducts | Mastic or UL 181 foil tape on the joints you can reach | +$500 – $2,000 |
| Zoning (2–3 zones) | Motorized dampers and a zone panel so floors heat and cool separately | +$1,750 – $5,000 |
| Asbestos test (pre-1980 home) | Test old duct wrap or tape before it is disturbed. Abatement not included. | +$250 – $750 |
How access changes the price
| Where the ducts run | Compared with an attic | Notes |
|---|---|---|
| Basement (exposed) | About 10–35% less than attic work | Easiest access; ducts already in conditioned space |
| Attic | Baseline | Supply ducts need R-8 insulation (IECC) |
| Crawlspace | About 15–50% more | Tight, slow access |
| Finished walls and ceilings | About 30–100% more | Fishing runs plus cut-and-patch |
Repair, sealing, and cleaning costs
For leaky or underperforming ducts, repair and sealing usually beat replacement. ENERGY STAR estimates that in typical homes about 20–30% of the air moving through the ducts is lost to leaks, holes, and poor connections, and that leaky ducts can cut heating and cooling efficiency by as much as 20%. Those are published estimates, not guaranteed savings for your home — a leakage test tells you what you actually have.
| Job | Typical range | Notes |
|---|---|---|
| Fix a disconnected or crushed run | $200 – $1,000 | — |
| Seal accessible ducts (mastic / foil tape) | $400 – $2,000 | Whole home |
| Aeroseal-type internal sealing | $1,300 – $5,000 | Per system; usually includes before/after testing |
| Insulate attic ducts to R-8 | $800 – $2,700 | Whole home; ~$2–$9 per linear foot |
| Duct leakage test | $200 – $500 | — |
| Duct cleaning | $270 – $1,000 | Only worth it for mold, vermin, or heavy debris |
Is duct cleaning worth it? The EPA does not recommend cleaning air ducts routinely — only when needed: substantial visible mold, vermin, or debris actually blowing out of the registers. If you see no sign of heavy dust or mold, cleaning is probably unnecessary, and sealing is the better use of the money.
Don't skip the returns
Returns are the most overlooked part of a duct system. An undersized or missing return starves the blower and raises static pressure; a bedroom with no return path goes pressurized when the door is shut and gets weak airflow; and a leaky return in an attic or crawlspace pulls in hot, dusty, unconditioned air. Check whether your return grilles are big enough with the free return grille calculator.
Code rules: sealing, insulation, and testing
- Joints must be sealed with UL 181-listed mastic or tape; ordinary duct tape is not allowed (IRC M1601.4.1).
- Attic supply ducts need R-8 insulation; smaller and other ducts R-6 (IECC).
- New or fully replaced systems are tested like new construction: total leakage of no more than 4.0 CFM25 per 100 sq ft of conditioned floor area (2021 IECC R403.3).
- Extensions are often exempt from testing, but not always. Phoenix's 2024 code exempts extensions yet requires a test once 25% or more of the registers or duct length is relocated or added; Washington and Philadelphia waive the test only under 40 ft of new duct in unconditioned space; California requires sealing plus HERS-verified testing on altered systems.
Cost by region
Duct work is labor-heavy — labor is roughly 60% of a typical project — so local rates move the total a lot. The same jobs, with a permit:
| Region | Where | Basement runs | Whole-home replace |
|---|---|---|---|
| Lower-cost area | Rural South and Midwest | $600 – $1,400 | $2,000 – $4,500 |
| National average | Most metros | $800 – $1,700 | $2,250 – $5,250 |
| High-cost area | Coastal metros, Northeast, Alaska | $1,100 – $2,500 | $3,250 – $7,250 |
What you can do yourself
Reasonable DIY
- Sealing accessible joints with mastic or UL 181 foil tape (ENERGY STAR lists this as a homeowner task)
- Re-hanging sagging flex duct
- Swapping registers and grilles
- Wrapping accessible ducts with insulation
Leave to a contractor
- Adding runs that change the system's airflow balance or static pressure
- Trunk modifications
- Anything that needs a Manual D design
- Touching pre-1980 duct wrap or tape before an asbestos test
Flex duct runs about $1–$4 per linear foot. Mastic, UL 181 foil tape, and replacement registers are inexpensive hardware-store items.
What these ranges don't include
National ranges, materials + labor combined, for a ~1,800 sq ft home unless noted. Excludes HVAC equipment, asbestos abatement, drywall finishing and paint beyond a primer-ready patch, framing changes, and mold remediation.
- HVAC equipment and any capacity upgrade (see the HVAC replacement cost page)
- Asbestos abatement (the test is an add-on; removal is not included)
- Drywall finishing and painting beyond a primer-ready patch
- Structural framing changes, soffits, and chases
- Mold remediation inside ducts
- Electrical work for zoning beyond low-voltage wiring
Where these numbers come from
Ranges reconcile national published data — HomeGuide, Angi, HomeAdvisor, Fixr, This Old House, Forbes Home, Today's Homeowner, and Modernize — with ENERGY STAR and EPA guidance and the IRC and IECC duct provisions. Published per-foot rates disagree by more than 100%, but whole-home totals by house size agree within about 25%, so project totals anchor the estimates and per-foot rates are shown for reference. A few rows (finished-space runs, moving a register, the upper-floor adjustment) are built from published components rather than quoted directly. Most sources compile homeowner and contractor quotes, which is why the ranges are deliberately wide. The model is reviewed annually; this page was last computed from data updated .
Size your ducts before you get quotes
Undersized runs are noisy and starve rooms; oversized ones waste money and airflow. The free duct size calculator sizes each run from its airflow with the equal-friction method — no signup.
Open the Duct Size Calculator →Frequently Asked Questions
How much does it cost to replace ductwork in 2026?
Replacing all the ductwork in a ~1,800 sq ft home with the ducts in an attic runs $2,250 to $5,250 including a permit, likely around $3,750, reusing the existing furnace and AC. Crawlspace access, runs to an upper floor, and sheet-metal trunks push toward the top. Putting ducts into a home that has none — fished through finished walls and ceilings — is a much bigger job at $6,000 to $12,500. Size the runs with the free duct size calculator before you compare bids.
How much does ductwork cost per linear foot?
Installed, insulated flex duct runs about $8 – $25 per linear foot and site-built rectangular sheet metal about $20 – $60. Published per-foot rates disagree by more than 100% because sources assume very different amounts of duct per home, so check a bid against the whole-job ranges too. A typical home has roughly 0.08–0.14 ft of duct per sq ft of floor area — about 140–250 ft for 1,800 sq ft.
How much does it cost to add a duct run?
Adding one supply run with a boot and register where the trunk is reachable from a basement or attic costs about $250 – $650. In a finished space, where the installer has to cut and patch drywall, plan on $600 – $1,800. A return-air run with a grille runs $250 – $750. Adding one or two runs to a finished basement typically totals $800 to $1,700, and extending ducts to a ~400 sq ft addition $1,700 to $3,250. More runs can overload a system sized for less, so have the installer check airflow.
Is duct sealing worth it?
Often, yes. ENERGY STAR estimates typical homes lose about 20–30% of the air in their ducts to leaks and poor connections. Sealing the ducts you can reach with mastic or UL 181 foil tape costs about $400 – $2,000; Aeroseal-type internal sealing, which reaches ducts inside walls, about $1,300 – $5,000 per system. Sealing and insulating attic ducts together runs $1,900 to $4,250. Start with a $200 – $500 leakage test so you know whether you have a problem before you pay to fix one.
Should I get my air ducts cleaned?
Usually not. The EPA does not recommend routine duct cleaning — only when there is substantial visible mold, vermin, or debris actually blowing out of the registers. Cleaning runs about $270 – $1,000. If you don't see heavy dust or mold, the money is better spent on sealing leaks, which ENERGY STAR ties to real efficiency gains.
Do I need a permit or a leakage test to change ductwork?
Usually a mechanical permit (about $50 – $400), and sometimes a test. Full replacements are generally tested like new construction — no more than 4.0 CFM25 of leakage per 100 sq ft of floor area under the 2021 IECC. Small extensions are often exempt, but the threshold varies: some codes waive testing under 40 ft of new duct in unconditioned space, others once you relocate or add 25% or more of the system, and California requires HERS-verified testing on altered ducts. Ask your building department before work starts.
Can I do ductwork myself?
Some of it. Sealing reachable joints with mastic or UL 181 foil tape (never plain duct tape — the IRC prohibits it), re-hanging sagging flex, swapping registers, and wrapping exposed ducts are reasonable homeowner jobs; flex duct itself runs about $1–$4 per foot. Adding runs, changing trunks, or anything that needs a Manual D design changes the system's airflow balance and is a contractor job. In a pre-1980 home, test old duct wrap or tape for asbestos before disturbing it. National ranges, materials + labor combined, for a ~1,800 sq ft home unless noted. Excludes HVAC equipment, asbestos abatement, drywall finishing and paint beyond a primer-ready patch, framing changes, and mold remediation.