The cost to replace flexible ductwork is usually $1,500-$5,500 for a partial or straightforward whole-home project, with larger or difficult jobs reaching $8,000 or more. Total price depends on the number and length of ducts, attic or crawlspace access, insulation level, local labor rates, and whether damaged connections or plenums also need work.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Partial replacement | $500 | $1,500 | $3,000 | Several runs, accessible area |
| Whole-home replacement | $1,500 | $4,000 | $8,000 | Typical single-family home scope |
| Installed flex duct | $4 per linear ft | $8 per linear ft | $15 per linear ft | Labor and materials vary by access |
| Inspection or diagnostic visit | $75 | $150 | $300 | May be credited toward work |
What a whole-home flexible duct replacement usually costs
A modest home with 100-150 linear feet of accessible duct may cost about $1,500-$3,000 to replace. A 1,500- to 2,500-square-foot home with 200-350 linear feet, multiple branches, and standard R-6 or R-8 insulated flex duct often lands around $3,000-$5,500. Extensive runs, tight crawlspaces, or ductwork serving a larger home can push the estimate to $6,000-$8,000 or more.
For a typical, accessible home, budgeting about $4,000 is a reasonable starting point, not a guaranteed quote. Per-foot rates often include duct, basic connectors, and installation, but contractors may price by run or project instead. Regional labor and required insulation ratings affect the total. Assumptions: U.S. midrange labor, standard insulated flexible duct, ordinary access, no major HVAC redesign.
How duct materials, labor, and removal appear on quotes
Quotes may separate materials from labor or bundle them into an installed per-foot rate. The table shows common allowances for a whole-home project; line items vary with duct length, crew size, and site conditions.
| Cost component | Typical range | How it is priced | What changes it |
|---|---|---|---|
| Insulated flex duct and fittings | $1-$4 per linear ft | Material allowance | Diameter, insulation, connectors |
| Installation labor | $50-$100 per worker-hour | Hourly or bundled | Access, routing, crew size |
| Removal and disposal | $200-$800 | Per job | Old duct volume and contamination |
| Sealing, supports, and balancing | $150-$700 | Per system or visit | Number of branches and adjustments |
| Permit or inspection | $0-$500 | Local fee | Jurisdiction and work scope |
Labor and access commonly account for a large share of the installed price. A labor estimate can be checked with ; for example, 16-28 hours at $60-$90 per hour equals $960-$2,520 before materials and disposal.
Why duct diameter, insulation, and access change the estimate
Run length and count are major pricing drivers. Replacing 100 linear feet is generally far less costly than replacing 300 feet, especially if the larger job has many branches and takeoffs. Common residential flex duct sizes range from about 6 to 16 inches in diameter; larger diameters and unusual transitions may require pricier materials and extra handling.
Insulation also matters. R-6 duct is a common baseline in many areas, while R-8 can add roughly $1-$3 per linear foot over comparable lower-rated duct. Local energy codes determine acceptable requirements. A clean, open attic may keep labor near the low end; a low-clearance crawlspace, cramped attic, or long run around framing can add 20%-50% to labor.
Ask the contractor to identify the duct length, diameter, insulation rating, and access assumptions behind the quote. A price based only on home square footage can hide differences in layout and existing system design.
How many crew hours a replacement may require
A partial replacement of a few accessible runs may take 3-8 labor hours. A straightforward whole-home job often requires 16-32 combined worker-hours, usually completed in one or two workdays. Complicated routing, removal of old duct, repairs to supports, or testing and airflow balancing may extend the schedule.
Contractors may send two or three technicians, so elapsed time is not the same as billed labor hours. A two-person crew working eight hours represents 16 worker-hours. Confirm whether the estimate lists crew time or total worker-hours, and ask whether cleanup, disposal, sealing, and system testing are included.
How attic and crawlspace conditions shift regional prices
Labor costs vary by metro area and contractor availability. As a broad estimate, dense coastal cities and high-cost Western markets may run 15%-30% above a national midrange quote. Smaller Midwestern or Southern markets may be 5%-15% below it, although remote locations can incur travel or scheduling charges.
Access can outweigh the regional difference. A home with a full, well-lit attic is usually easier to work in than one with a narrow hatch and limited clearance. Crawlspace moisture, pests, or contaminated old insulation may require remediation before installation. Compare quotes from contractors pricing the same footage, insulation rating, removal scope, and testing.
When removal, insulation, or repairs add to the duct bill
Old duct removal commonly adds $200-$800, and difficult disposal or contaminated material can cost more. Replacing damaged insulation around duct runs may add $1-$3 per square foot of affected area. A new plenum or transition fitting may add $150-$600, while air balancing or leakage testing can add about $100-$400 if not included.
Ask whether the quoted work includes reconnecting each branch, sealing joints, supporting runs at suitable intervals, and checking airflow. Cleaning, duct sealing, or pest remediation should be listed separately when they are not part of the replacement. If a contractor identifies mold or asbestos-containing material, a qualified specialist may be needed before duct work continues.
Repairing a few flex duct runs versus replacing them all
For one or two accessible tears or loose connections, a repair may cost $150-$600, depending on diagnosis and access. Replacing a short branch may cost $250-$900. Those options can be economical when the rest of the system is intact, but repeated leaks, crushed runs, deteriorated insulation, or widespread poor airflow may make broader replacement more practical.
Compare the cost of repairing the specific damaged runs with a written price for replacing all affected duct. Whole-system replacement is not automatically necessary just because one branch has failed; conversely, multiple patch jobs can approach the price of new duct without correcting hidden damage.
Ways to keep a flexible duct replacement within budget
Have the contractor document which runs are damaged and which can remain. Replacing only failed sections can limit material and labor, while bundling several necessary runs into one visit may avoid repeated diagnostic or minimum charges. Clear stored items from attic access points and pathways before the crew arrives, but do not enter unsafe areas or disturb suspected hazardous material.
Request two or three itemized quotes that use the same scope, duct rating, and removal terms. Avoid paying for a higher insulation rating or extensive redesign unless code, performance needs, or the system layout supports it. Keep a 10%-15% contingency for hidden access or connection repairs, and approve additions in writing before work proceeds.