New ductwork cost: replace, install & when it's worth it
Replacing the ductwork in an average home runs $1,400 to $5,600 — about $25 to $55 per linear foot installed — while adding ducts to a home that never had any costs $2,400 to $6,600. Here's the full price picture by home size, the signs it's actually time to replace, and when sealing your existing ducts is the smarter, cheaper fix.
Those are the classic signs of failing ductwork. Call (888) 810-2291 for a licensed local contractor to inspect and quote it.
How much does it cost to replace ductwork?
Replacing ductwork typically costs $1,400 to $5,600 for an average home, or about $25 to $55 per linear foot installed — material plus labor. A full whole-home replacement in a large or hard-to-reach house can reach $8,000 to $12,000 or more. Budget sheet-metal runs in easy-access spaces can drop to roughly $16 to $19 per foot, while insulated flex and tight crawlspaces push toward the top of the range. Here are the reported ranges, verified across cost sources:
| Basis | Typical range |
|---|---|
| Replace existing ductwork (typical) | $1,400–$5,600 |
| Whole-home replacement (large / complex) | $8,000–$12,000+ |
| By the linear foot (material + labor) | $25–$55/ft |
| Budget metal, DIY-adjacent runs | $16–$19/ft |
| New install — no existing ducts | $2,400–$6,600 |
| Inspection / duct-leakage test | $40–$100 |
| Permit (where required) | $50–$250 |
The single biggest swing isn't the duct material — it's access and layout. A rambling attic with tight clearances or a low crawlspace can double the labor hours over an open basement with a straight trunk line.
How much does new ductwork cost by home size?
As a rule of thumb, plan on roughly $4,000 to $7,000 for a small home and $7,000 to $12,000 for a larger one — bigger homes need more linear feet, more branches, and more registers. Use conditioned square footage as your starting point, then let access and complexity move you within the band:
| Home size (conditioned) | Replacement cost |
|---|---|
| 1,000–1,500 sq ft | $4,000–$7,000 |
| 1,500–2,000 sq ft | $5,500–$9,500 |
| 2,000–2,500 sq ft | $7,000–$12,000 |
What does it cost to install ducts in a home with none?
Adding ductwork to a home that never had any runs about $2,400 to $6,600 — sometimes lower than a full replacement because there's nothing to tear out, but the installer still has to cut chases through floors and ceilings, run the trunk and branch lines, and add every register and return from scratch. In a finished home with no easy path for ducts, that access work is where the cost lives. If you're weighing whole-house ducts against the disruption, a ductless mini split often wins on both cost and efficiency — see mini split vs. central air for the trade-off.
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When should you replace your ductwork?
Replace your ducts when they're old and underperforming, or damaged, badly sized, or contaminated — not simply because they're old. Ductwork lasts about 10 to 20 years, and most homes replace at the 15-to-20-year mark, ideally alongside a new furnace or AC so the ducts get sized to the new equipment. These are the signals worth an inspection:
The ducts are 15–20+ years oldREPLACE
Ductwork lasts about 10 to 20 years. Past the 15-year mark, the joints loosen, insulation degrades, and flex duct sags — so if a system this old is also underperforming, replacing the ducts alongside a new furnace or AC is usually the better spend than patching them again.
Rooms heat and cool unevenlyINSPECT
One room that's always hot or cold points to ducts that are leaking, undersized, crushed, or disconnected. Sealing fixes leaks; but if a run is the wrong size or was never balanced, replacing or reworking that section is what actually evens the house out.
Whistling, rattling, or booming ductsINSPECT
Whistling means air is being forced through leaks or an undersized return; banging or booming ('oil-canning') is thin metal flexing under pressure. Both signal ductwork that's fighting the airflow it was given — worth an inspection before it drives up your bills.
Energy bills keep climbingSEAL/REPLACE
Ducts running through an unconditioned attic or crawlspace can leak away 20 to 30% of the air you pay to condition. If bills are creeping up with no change in habits, leaky or uninsulated ducts are a prime suspect — sealing or replacing them saves 10 to 40%.
Mold, dust, or a pest historyREPLACE
Mold inside porous duct board, or ducts that have hosted rodents, often can't be cleaned to a healthy state — replacement is the honest fix. Persistent dust from the vents after a good filter change points the same way.
Repair, seal, or replace — which do you need?
Most duct problems are leaks, not failures — and a leak gets sealed, not replaced. A typical home loses 20 to 30% of its heated and cooled air through disconnected joints and unsealed seams, and sealing recovers most of that for a fraction of replacement cost, saving 10 to 40% on bills. Reserve full replacement for ducts that are aged out, crushed, badly undersized, or contaminated with mold or pests. The practical order: seal first, insulate the runs in unconditioned space, and replace only the sections that are genuinely beyond help. Our companion guides cover each move:
- Leaky air ducts — seal, repair, or replace: how to find leaks and stop the 20–30% loss.
- Duct insulation: R-values and where it pays off, once the ducts are sealed.
- Types of ductwork: sheet metal vs. flex vs. fiberboard, if you are replacing.
What drives the price of a ductwork job?
Four things move a duct quote more than anything else, which is why two homes of the same size can be quoted thousands apart:
Linear footage & number of runs$25–$55/ft
You pay by the foot, so a sprawling layout with many branches and registers costs more than a compact one. This is the base of every estimate.
Access to the spacebiggest swing
An open, walk-in basement is cheap to work in; a low crawlspace or a finished attic with tight clearances multiplies the labor hours. Access, not material, is usually what separates a $4,000 job from an $8,000 one.
Material & insulationmetal / flex / board
Rigid sheet metal costs more up front than flexible duct but lasts longer; insulated (R-6/R-8) duct costs more than bare. See types of ductwork for the trade-offs.
Permits, testing & teardown$50–$250
Many areas require a mechanical permit ($50–$250) and a post-work duct-leakage test; removing and disposing of old ducts adds labor. A licensed contractor rolls these into the quote — ask that they're itemized.
Get a licensed HVAC contractor on the phone
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Frequently asked questions
How much does it cost to replace ductwork?
Replacing ductwork typically runs $1,400 to $5,600 for an average home, or $25 to $55 per linear foot installed. A full whole-home replacement in a large or hard-to-access house can reach $8,000 to $12,000 or more.
How much does new ductwork cost per square foot?
Expect roughly $4,000 to $7,000 for a 1,000–1,500 sq ft home, $5,500 to $9,500 for 1,500–2,000 sq ft, and $7,000 to $12,000 for 2,000–2,500 sq ft. Layout complexity and attic or crawlspace access move the number more than floor area alone.
How much does it cost to install ducts where there were none?
Adding ductwork to a home that never had any runs about $2,400 to $6,600, because the installer has to cut chases, run trunks and branches, and add registers and returns from scratch. Homes without existing ducts sometimes come out ahead with a ductless mini split instead.
When should ductwork be replaced?
Replace ducts when they're 15 to 20+ years old and underperforming, when rooms stay uneven despite sealing, when you hear whistling or booming, when bills keep climbing from leaks, or when there's mold or a pest history that can't be cleaned out. Many leaks can be sealed instead of replaced.
How long does ductwork last?
Ductwork lasts about 10 to 20 years. Sheet metal can last longer if it stays dry and sealed; flexible duct is shorter-lived because it sags, kinks, and its inner liner degrades. Most homes replace ducts at the 15-to-20-year mark, often alongside a new furnace or AC.
Is it cheaper to seal ducts than replace them?
Yes. Sealing leaky ducts is far cheaper than replacing them and recovers most of the lost efficiency — a typical home loses 20 to 30% of its conditioned air to leaks. Replace only when ducts are old, damaged, badly sized, or contaminated; otherwise seal and insulate.
Do I need a permit to replace ductwork?
Often yes — many jurisdictions require a mechanical permit for duct replacement, typically $50 to $250, and some require a post-work duct-leakage test. A licensed contractor pulls the permit and handles the inspection; ask that it's included in the quote.
Should I replace ductwork when I replace my furnace or AC?
It's often the right time. If the ducts are old, leaky, or the wrong size for the new equipment, replacing them together avoids paying twice for access and lets the installer size the ducts to the new system's airflow. New equipment on bad ducts underperforms.