HVAC ductwork typically costs $10-$25 per linear foot installed, with flexible ducts often cheaper and custom sheet-metal runs more expensive. The duct cost per foot depends on material, diameter, access, labor rates, and whether the job replaces existing runs or adds new ones.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Flexible duct installed | $5 per ft | $8 per ft | $12 per ft | Common for accessible branch runs |
| Sheet-metal duct installed | $10 per ft | $17 per ft | $30 per ft | More costly for custom fabrication |
| Duct-board installed | $7 per ft | $12 per ft | $18 per ft | Price varies with size and layout |
| Typical home project | $1,000 | $3,500 | $8,000+ | Partial or full replacement; scope varies |
What HVAC ductwork costs per foot by material
For a straightforward replacement using accessible routes, flexible insulated duct commonly runs $5-$12 per linear foot installed. It is often used for short branch connections between a main trunk and registers. Kinks, long unsupported spans, or tight turns can reduce airflow, so the lowest material quote is not always the best value.
Sheet-metal ductwork generally costs $10-$30 per foot installed. Straight standard sections may fall near the low end; custom transitions, unusual shapes, and difficult fabrication push rates higher. Fiberglass duct board is often $7-$18 per foot installed, though local availability and the number of fittings affect the quote.
For budgeting, $8-$18 per foot is a reasonable planning range for many residential runs, but material and access can shift the installed rate substantially.
Per-foot rates usually describe duct runs rather than every part of the job. Contractors may price fittings, takeoffs, boots, dampers, registers, insulation, sealing, and equipment connections separately. A project with 100 feet of duct therefore does not necessarily cost 100 times the quoted straight-run rate.
Assumptions: U.S. residential work, standard materials, ordinary access, and no major framing or equipment changes.
How sheet metal, insulation, and labor shape the quote
A contractor’s estimate combines duct material with the work needed to measure, remove, route, connect, seal, and test the system. Labor can account for a large share of a replacement, particularly when ducts sit in a finished ceiling or cramped crawlspace. A useful labor estimate can be expressed as .
| Quote component | Typical price | What changes it | Billing basis |
|---|---|---|---|
| Flexible duct material | $2-$6 | Diameter, insulation, quality | Per linear ft |
| Sheet-metal material | $4-$12 | Gauge, shape, fabrication | Per linear ft |
| Installation labor | $75-$150 | Access, crew size, removal | Per worker-hour |
| Fittings and registers | $25-$150 | Number and type of connections | Per item |
| Removal and disposal | $200-$1,000 | Old duct volume and access | Per project |
| Airflow testing and sealing | $150-$600 | System size and test scope | Per project |
Some bids bundle the material, labor, and accessories into an installed-per-foot figure; others list a total project price. Compare what each quote includes, especially insulation, mastic or approved sealing, removal, register connections, and post-installation airflow checks. A low per-foot number can exclude costly fittings or preparation work.
For residential HVAC labor, rates of $75-$150 per technician-hour are common budgeting figures, though local charges may be outside that range. A small crew may spend a day or more on a partial replacement and several days on a complex whole-house job. Estimates should identify whether labor is hourly, fixed-price, or included in the unit rate.
How diameter, run length, and access change installed rates
Duct diameter affects both material use and the airflow the system can deliver. A 6-inch branch may cost less per foot than a 10- or 12-inch run, while large trunks and transitions require more material and handling. The design must match the HVAC system’s airflow needs; reducing size just to lower the quote can cause noise, poor comfort, and equipment strain.
Long routes can lower the average price per foot when they use repeated straight sections, but short custom jobs may have a higher effective rate because setup, mobilization, and fittings are spread over fewer feet. For example, a 20-foot run with several turns may cost more per foot than a 100-foot run in an open basement, even if the total is lower.
Access is another major price driver. Open basements and unfinished attics generally cost less than finished ceilings, narrow crawlspaces, or routes requiring drywall removal. When ducts are above a finished ceiling, access openings and patching can add roughly $300-$2,000 or more, depending on the number and finish of repairs.
Check whether the estimate states duct size, insulation level, footage, fitting count, and the location of each run. Those details make competing bids easier to compare and help reveal whether an apparently low price covers the same scope.
Insulation requirements also vary by location and duct placement. Ducts in unconditioned attics or crawlspaces often need more insulation than runs inside conditioned space. Adding insulation or replacing poorly insulated sections may add about $1-$4 per foot, depending on product and access.
Three residential duct quotes with different scopes
These examples illustrate how total price changes with material and site conditions. They are not fixed national rates; local labor, project minimums, and equipment connections can change the final estimate. Each assumes an existing HVAC system remains in place and no major redesign is required.
| Project scenario | Scope and rate | Added charges | Estimated total |
|---|---|---|---|
| Accessible branch repair | 40 ft flexible duct at $8/ft | $250 fittings and sealing | $570 |
| Partial attic replacement | 120 ft duct at $14/ft | $500 removal and $350 registers | $2,530 |
| Custom trunk and branches | 180 ft sheet metal at $22/ft | $1,200 fabrication and access work | $5,160 |
In the first example, the short run is accessible and uses flexible duct, so the per-foot rate is moderate but fittings make up a noticeable share of the bill. The second includes old duct removal and multiple connections. The third involves more expensive sheet metal and custom work, producing a higher total despite a similar residential setting.
Contractors may also set a minimum service charge for small repairs. A repair involving only 10 feet of duct can still cost $300-$800 once inspection, travel, sealing, and labor are included. Ask for both the unit rate and the minimum project charge before approving a short-run job.
What regional labor rates mean for duct prices
Labor and operating costs vary across the United States. As a broad estimate, installed duct prices in lower-cost rural or Midwestern markets may be 5%-15% below a national planning figure. Large coastal cities and high-cost metro areas can run 15%-35% above it, especially when access is limited or contractor schedules are full.
Climate affects the work as well as wages. Hot or cold regions may have more demand for duct upgrades, and local building requirements can call for specific insulation or sealing practices. A home in a humid climate may also need careful attention to insulation and condensation control for ducts routed through unconditioned spaces.
Regional comparisons should use equivalent scope. A quote that includes removal, new registers, air balancing, and attic access work cannot be compared directly with a bare per-foot material-and-installation rate. Use local written bids with the same footage, material, insulation, and finish requirements rather than relying on a single national average.
Permits may be needed when duct changes are part of a larger HVAC alteration, equipment replacement, or work regulated by the local jurisdiction. Simple duct repairs may not require a separate permit, but rules differ. Permit and inspection charges can range from about $50-$500 when applicable, with larger mechanical projects sometimes costing more.
When a duct repair costs less than replacement
Not every damaged run needs a full replacement. A disconnected joint, small tear, loose strap, or unsealed seam may be repaired for roughly $150-$600, depending on access and the number of locations. Sealing a reachable leak may cost less than replacing a complete branch, while a difficult crawlspace visit can raise the minimum charge.
Replacement becomes more practical when multiple sections are crushed, contaminated, poorly supported, badly sized, or deteriorated. If more than about 20%-30% of the system needs work, compare the cost of piecemeal repairs with a planned replacement. That threshold is a budgeting prompt, not a universal rule; age, condition, and system performance matter.
Old ductwork does not automatically need replacement when a furnace or air conditioner is changed. A contractor can inspect its size, leakage, insulation, and condition. A new HVAC unit connected to undersized ducts may perform poorly, but replacing sound, correctly sized ducts solely because the equipment is new can add avoidable expense.
Request a repair option and a replacement option when the damage is localized or the condition is uncertain. The quote should explain what the repair addresses and what risks remain, rather than treating every old duct as an automatic replacement.
How to lower a ductwork estimate without hurting airflow
Keep the project scope clear. Ask the contractor to separate necessary repairs from optional improvements, identify the runs being replaced, and state whether the price includes removal and testing. If only a few branches are damaged, a targeted repair may be more economical than replacing every duct in the house.
Choose material based on the route, not just the lowest per-foot price. Flexible duct can be cost-effective for short, accessible branches when installed with proper support and minimal bends. Sheet metal may make more sense for trunks, exposed runs, or locations where durability and precise shapes matter. Avoid specifying a material that does not suit the system design.
Homeowners can reduce labor time by clearing stored items from attic or basement access paths and identifying registers and problem rooms before the crew arrives. They should not remove insulation, cut access holes, or alter ducts unless the contractor approves; poor preparation can create safety issues or added repair work.
Compare at least two or three itemized estimates with the same footage, material, insulation, fittings, removal, and testing. Ask whether the contractor can combine duct work with a planned HVAC service visit, but do not accept unnecessary equipment upgrades as a condition of basic duct repair. The strongest savings usually come from controlling scope and comparing equivalent bids, not from under-sizing ductwork.
Scheduling during a contractor’s less busy period may improve availability, although it does not guarantee a lower price. Emergency work, weekend appointments, or a repair needed during extreme weather can carry rush charges or limited material choices. For a nonurgent replacement, obtaining estimates before peak heating or cooling demand may allow more time to compare options.
What to verify before accepting a per-foot duct quote
Confirm whether the quoted footage is measured along the installed route and whether branches, trunk lines, transitions, and vertical drops are priced at the same rate. Some contractors quote straight sections per foot and charge separately for elbows, plenums, dampers, boots, and register boxes. Requesting a marked-up layout can clarify the quantities.
Check the insulation specification and whether the ducts will be sealed at joints. Also verify if the bid includes removal of old materials, disposal, protection of finished areas, access-hole repair, and final airflow checks. In homes with suspected asbestos-containing insulation or other hazardous material, specialized inspection and abatement may be required and are not covered by ordinary duct pricing.
Ask how the contractor will confirm that the duct sizes work with the existing equipment. A complete replacement may require airflow balancing or minor adjustments, while a layout change can require design work. A contractor who explains the scope and limitations gives a more useful estimate than one offering only a low per-foot figure.
Before signing, compare the total installed price, not only the advertised rate per foot. A complete written scope helps prevent surprise charges and provides a clear basis for evaluating workmanship and warranty terms.