Ductwork Replacement Cost (2026)

Most homeowners don't think about their ductwork until something goes wrong — and when an HVAC tech finally gets into the attic or crawlspace, the news is often not good. Ducts that are 20-plus years old, wrapped in deteriorating fiberglass, held together with deteriorating mastic or dried-out tape, and leaking conditioned air into an unconditioned attic. That's not unusual. It's the norm in houses built before 2000.

Ductwork replacement is one of the least understood HVAC costs. Homeowners getting quotes are often blindsided because they assumed the ductwork was fine — nobody told them otherwise. This guide covers what full ductwork replacement actually costs in 2026, what drives that number up or down, and when replacement isn't the right answer at all.

Ductwork Replacement Cost by Home Size

The most accurate way to estimate ductwork replacement cost is by home size, because the square footage determines how many linear feet of duct the system needs and how many supply and return registers the contractor has to connect.

Home Size	Estimated 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
2,500–3,000 sq ft	$9,000–$15,000

These ranges assume a complete tear-out and replacement of an existing duct system, with one HVAC unit and one zone. A two-story home with two systems will cost more. A slab-foundation house with attic ducts in a hot climate will trend toward the higher end because attic access is brutal in summer and labor hours stack up.

Per linear foot, installed ductwork runs $25–$55 depending on material. Most single-family homes have 150–350 linear feet of ductwork, which is how you get to those project totals.

Duct Material Costs: Flex, Sheet Metal, and Fiberboard

The material your contractor uses changes the cost — and more importantly, changes how long the new ductwork will last.

Flexible Duct (Flex Duct)

Installed cost: $10–$25 per linear foot

Flex duct is the most common material used in residential replacement work today. It's a spiral wire core wrapped in plastic and insulation — relatively inexpensive, easy to route around framing, and fast to install. A good flex duct installation done correctly lasts 15–20 years.

The weakness of flex duct is also its strength: flexibility. A run that gets kinked, squashed, or left with a tight bend loses airflow significantly. Poor flex duct installation — too many bends, runs that sag, undersized diameter — is one of the most common problems HVAC technicians find in older homes. When you're paying for new ductwork, make sure your contractor sizes the duct properly and supports it every 4–5 feet.

Sheet Metal (Galvanized Steel)

Installed cost: $35–$60 per linear foot

Sheet metal ductwork is fabricated in sections and assembled on-site or delivered pre-cut. It costs more upfront because it requires skilled sheetmetal work and more labor hours to install. The payoff is durability: galvanized steel ductwork can last 25+ years without the sagging, kinking, and liner deterioration that flex duct eventually develops. It also delivers better airflow because the interior is smooth with no corrugation.

For homes where the ductwork is in a finished ceiling or a location that's difficult to access later, sheet metal is worth the premium. You're paying more now to avoid having to do this again.

Fiberboard Duct

Installed cost: $10–$20 per linear foot

Fiberboard ducts are rigid fiberglass boards formed into rectangular channels. They were widely used through the 1980s and 1990s. Very few contractors install fiberboard today — the material is prone to moisture absorption, interior liner delamination, and mold growth under the right conditions. If your home has original fiberboard ductwork and it's more than 20 years old, replacement is almost always the recommendation, and your contractor will likely use flex or sheet metal for the new system.

Partial Replacement vs. Full Replacement: When Each Makes Sense

Full replacement isn't always the answer. A duct system that has one damaged section — a collapsed flex duct in the attic, a disconnected trunk line — can often be addressed with a partial replacement or targeted repair for $1,500–$4,000 rather than a full system replacement at $8,000+.

The decision comes down to three things:

Age of the system. Ductwork under 15 years old with isolated damage is generally a good candidate for partial repair. Ductwork over 20 years old with widespread deterioration is a candidate for full replacement — patching a system that's failing everywhere doesn't buy you much.

Scope of the leakage. A duct blaster (pressurization) test can quantify how leaky your system is as a percentage of total airflow. If leakage is concentrated in one or two sections, partial repair makes sense. If it's spread throughout the system, you're patching a sieve.

What else is happening. If you're replacing your furnace or air conditioner at the same time, this is the right moment to address ductwork. Contractors can access everything they need, and bundling the work saves on labor. Replacing the equipment and leaving old, leaky ductwork behind means your new high-efficiency system will never perform to spec. See our furnace replacement cost guide and central AC installation cost guide for what to budget when doing all three.

Minor duct repairs — sealing accessible joints, replacing a short section of flex duct, reattaching a disconnected boot — typically run $300–$1,500 and are worth doing when the overall system is in reasonable shape. You can find current benchmarks for repair costs in our HVAC repair cost guide.

Duct Sealing (Aeroseal): A Real Alternative — With Limits

If the problem is leakage rather than physical damage, duct sealing with Aeroseal is worth considering before committing to full replacement.

Aeroseal is an aerosol polymer sealant injected into the pressurized duct system. The particles travel with the airflow and deposit at the leak points — sealing gaps and holes from the inside without the contractor needing to physically access every duct run. The process takes a few hours and generates a printed report showing before-and-after leakage measurements.

Cost: $1,500–$3,500 for a typical single-family home, depending on system size.

The energy savings case is real. According to ENERGY STAR, in a typical house about 20 to 30 percent of the air moving through the duct system is lost to leaks, holes, and poorly connected ducts. Sealing those leaks can measurably cut heating and cooling costs.

But Aeroseal has hard limits. It works on leakage — small gaps, loose joints, pinhole failures. It does not fix collapsed ducts, disconnected sections, mold-damaged duct liner, or ducts where the physical structure has failed. If your HVAC technician is recommending Aeroseal for a duct system with visible damage or confirmed mold, get a second opinion. Aeroseal buys you years on a system that's otherwise structurally sound. It doesn't resurrect one that's failing.

The comparison math is straightforward: if your ducts are otherwise in good shape and the issue is leakage, $2,500 in Aeroseal versus $8,000 in full replacement is an easy decision. If the ducts are 25 years old and deteriorating throughout, replacement addresses everything that sealing won't.

Signs Your Ductwork Needs Replacement

Most homeowners don't know their ductwork has a problem until an HVAC tech tells them. These are the signals to watch for.

Age over 15–20 years. Flex duct and fiberboard have an expected lifespan of 15–20 years. Sheet metal can push 25 years. If you don't know how old your ductwork is, check the original permit records or ask an HVAC tech to assess. Age alone isn't the deciding factor — condition is — but old ductwork combined with any of the symptoms below is a strong replacement indicator.

Uneven temperatures between rooms. If one side of your house is consistently warmer or cooler than the other, and the problem persists across seasons, duct leakage or a crushed duct run is the likely cause. Your system is moving conditioned air somewhere it's not supposed to go.

Energy bills climbing without explanation. A spike in heating and cooling costs when nothing else has changed — same household, same thermostat settings — often points to duct leakage. You're paying to condition air that's escaping into your attic or crawlspace. The DOE and ENERGY STAR data on 20–30% energy loss through leaky ducts is not hypothetical. It translates directly to hundreds of dollars a year in wasted energy costs for the average household.

Visible damage in accessible areas. If you can see your ductwork in the attic, basement, or crawlspace, look for: disconnected joints, collapsed flex duct sections, duct tape that's dried, cracked, or peeling (duct tape — the hardware store kind — was never meant for HVAC ductwork and fails within a few years), insulation that's falling off, or any visible mold growth.

Excessive dust throughout the house. Ducts that are leaking air are also pulling in unconditioned air from attics, crawlspaces, and wall cavities — and whatever's in that air, including insulation particles, dust, and allergens, ends up distributed through your living space.

Rattling or whistling sounds from vents. Loose duct sections, disconnected flex duct, or collapsing duct walls create noise when the system runs. This isn't a minor issue — it usually indicates physical damage that won't be fixed by sealing.

A thorough furnace tune-up and inspection often catches duct problems before they become expensive surprises, because a good technician checks static pressure and airflow, not just the equipment.

New Ductwork and System Efficiency

A new duct system on an older, leaky HVAC system is a meaningful upgrade. But the real efficiency gain comes when new ductwork accompanies properly designed and installed equipment.

Here's what the numbers look like: if your current system is losing 25% of conditioned air to duct leakage, your 3-ton air conditioner is functionally performing like a 2.25-ton unit. You're paying to run a 3-ton system and getting substantially less cooling delivered to the living space. A new duct system with properly sealed joints and adequate insulation restores that lost capacity.

Right-sizing matters too. Many older duct systems were installed with undersized returns, trunk lines that don't match equipment capacity, or supply runs that are too long for the pressure the equipment can deliver. A competent duct replacement isn't just swapping old material for new — it should include a Manual D calculation to verify the duct design is matched to your equipment and the layout of your home. If a contractor quotes ductwork replacement without mentioning load calculations or duct sizing, ask about it.

New ductwork also gives you the opportunity to address insulation. Ducts running through an unconditioned attic lose a significant amount of thermal energy even if they don't have physical leaks — the hot attic air conducts through the duct wall. Current code in most states requires R-6 or R-8 insulation on ducts in unconditioned spaces. Older ductwork often has none, or has original insulation that's degraded.

Adding Ductwork to a Home That Doesn't Have It

This is a fundamentally different project from replacing existing ductwork, and the cost reflects that.

Installing a complete duct system in a home that's never had one — a house built without central HVAC, or one that was previously all-electric baseboard or radiant heat — runs $10,000–$20,000 for the ductwork alone, before counting the air handler, furnace, or condensing unit. Retrofitting ductwork requires cutting into walls, ceilings, and floors; framing out duct chases; and doing drywall repair afterward. Labor hours are much higher than a replacement job.

For homes without ductwork, the conversation often turns to alternatives: ductless mini-split systems can deliver zoned heating and cooling without any ductwork at all, typically for $6,000–$14,000 for a whole-home multi-zone system. In some cases that's the more practical and cost-effective path, particularly in older homes with thick plaster walls or finished ceilings where duct chases would be extremely disruptive to install.

If you're weighing ductless vs. adding ducts for a new central system, that's a conversation worth having with a qualified HVAC contractor who can assess your home's layout. The right answer depends on your floor plan, your climate, and your long-term plans for the house.

What Drives Ductwork Replacement Cost Up or Down

Two identical houses can have very different ductwork replacement quotes. Here's what moves the needle:

Accessibility. Attic ducts in a 6/12 pitch roof are reasonably accessible. Ducts in a crawlspace with 18 inches of clearance, or in a finished ceiling, add hours to the job. Labor is the largest variable in any ductwork quote.

Duct material selected. Sheet metal costs 2–3x more than flex duct per linear foot installed. It's more durable, but the upfront cost difference is real.

Number of zones. Two-story homes with separate upstairs and downstairs systems have twice the ductwork and often require coordination between zones. Cost scales accordingly.

Geographic labor rates. HVAC labor in San Francisco or New York runs 40–60% higher than the national average. The same job that costs $7,000 in the Midwest might be $11,000 in a high-cost metro.

Permit requirements. Some jurisdictions require a permit for ductwork replacement. Permit fees are typically $100–$300, but they add inspection scheduling to the project timeline.

Disposal of old ductwork. Removing and disposing of old flex duct, fiberboard, or sheet metal takes time and usually involves a disposal fee. Make sure your quote includes this — it's occasionally left out of initial estimates.

Getting an Accurate Quote

Get at least three quotes from licensed HVAC contractors. Ask each one:

Are you pricing flex duct or sheet metal?
Does this include removal and disposal of the existing ductwork?
Will you be doing Manual D duct sizing, or are you replacing like-for-like?
What insulation R-value will the new ducts have?
Does this price include all permits if required?

A contractor who can't answer the third and fourth questions is probably doing a straight swap — new material in the same configuration as the old, with the same sizing problems if any existed. That's not always wrong, but you should know what you're getting.

One more thing: there is no federal tax credit for ductwork replacement as of 2026. The 25C energy efficiency tax credit covers qualified heating and cooling equipment — heat pumps, furnaces, air conditioners — not duct installation. Don't let a sales pitch about "tax credits" change your calculus on a ductwork job.

If you need help finding qualified HVAC contractors in your area, the technician finder on HVACJobs.IO can point you toward licensed professionals with the credentials to do this work correctly.

Frequently Asked Questions

How much does ductwork replacement cost for a 2,000 sq ft house?

For a 2,000 square foot single-story home, expect to pay $7,000–$12,000 for a complete ductwork replacement. The range reflects differences in duct material (flex vs. sheet metal), accessibility (attic vs. crawlspace), and local labor rates. Get at least three quotes from licensed contractors.

How long does ductwork last?

Flex duct and fiberboard typically last 15–20 years with proper installation. Sheet metal (galvanized steel) can last 25 years or more. Ductwork installed before 2000 in many homes is at or past its expected service life. Age alone isn't a replacement trigger, but age plus visible damage or performance problems usually is.

Is it worth replacing ductwork when getting a new HVAC system?

Often, yes. If your ductwork is over 15 years old and showing signs of wear, replacing it alongside a new furnace or air conditioner makes practical sense — the labor overlap reduces total cost compared to doing two separate jobs, and your new high-efficiency equipment won't deliver its rated performance through leaky, undersized ducts.

What is Aeroseal and how much does it cost?

Aeroseal is an aerosol sealant injected into your pressurized duct system that seals leaks from the inside. It costs $1,500–$3,500 for a typical home and is a viable alternative to full replacement when the ductwork is structurally sound but leaking. It does not repair collapsed ducts, disconnected sections, or mold-damaged material.

How do I know if my ductwork needs replacing?

The most common signs are: uneven temperatures between rooms, high energy bills that have increased without explanation, visible damage (collapsed flex duct, peeling tape, disconnected joints) in accessible areas, excessive household dust, or rattling and whistling sounds from your vents. A duct pressurization test performed by an HVAC contractor can quantify how much leakage you actually have.

Can I replace ductwork myself?

Duct replacement is generally not a DIY project. It involves equipment sizing calculations, physical work in tight attic and crawlspace conditions, and connections to your HVAC equipment that must be sealed correctly to pass inspection in many jurisdictions. The consequences of undersized duct runs or improper connections are ongoing — reduced efficiency, uneven comfort, potential equipment damage. Hire a licensed contractor.

Does new ductwork reduce energy bills?

Yes, measurably. ENERGY STAR data shows that typical homes lose 20–30% of conditioned air through duct leaks. Replacing a badly leaking system with properly sealed new ductwork can cut heating and cooling costs significantly — often $300–$600 per year for the average household depending on energy prices and how leaky the original system was.

Is ductwork replacement covered by homeowners insurance?

Standard homeowners insurance covers sudden and accidental damage — a tree falls through your roof and damages the duct in the attic, for example. It does not cover wear, deterioration, or age-related failure, which is what most ductwork replacement involves. Check your policy, but don't expect routine replacement to be covered.

Pricing data in this article is based on 2026 contractor estimates aggregated from national cost databases and regional contractor surveys. Costs vary by location, contractor, and project specifics. Always get multiple quotes before committing to a project of this size.

Sources:

Ductwork Replacement Cost 2026: What You'll Actually Pay