Replacing ductwork in an attic typically runs from $1,200 to $8,500 depending on home size, duct type, and access; this article shows typical cost, per-linear-foot pricing, and the biggest price drivers for attic duct replacement. The cost examples and ranges below assume U.S. labor, accessible attic, and standard medium-efficiency materials.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Small 1-2 bedroom house | $1,200 | $2,800 | $4,500 | Assumptions: 600–1,000 sq ft, partial trunk replacement. |
| Typical 1,800–2,500 sq ft home | $2,500 | $5,500 | $8,500 | Assumptions: full attic duct replacement, standard flex/ductboard. |
| Per linear foot (materials + install) | $6 per ft | $12 per ft | $25 per ft | Assumptions: run length, transitions, fittings included. |
Typical Total Price For Replacing Attic Duct Runs
Full attic duct replacement: expect $2,500-$5,500 for an average 1,800–2,200 sq ft home replacing trunk, branches, and insulation; smaller homes can be as low as $1,200 and complex multi-zone systems up to $8,500+. Average projects replace 150–450 linear feet of ductwork at about $8-$15 per linear foot installed.
Assumptions: Midwest labor rates, standard 8–10 supply/return outlets, accessible attic, standard insulation R-6 to R-8.
How Duct Replacement Quotes Break Down By Cost Component
| Materials | Labor | Equipment | Delivery/Disposal | Permits |
|---|---|---|---|---|
| $300-$2,000 (flex, ductboard, sheet metal) | $800-$3,500 () | $0-$400 (scaffolding, lifts) | $50-$400 (debris haul) | $0-$300 (local code) |
Materials and labor usually account for 70–90% of the total quote; specialty sheet-metal trunks push material cost higher.
How Per-Unit Pricing Works: Per Linear Foot, Per Vent, Per Job
Per-linear-foot prices vary: basic insulated flex runs $6-$12 per ft; sheet metal trunks $12-$25 per ft; replacing a single branch or register runs $75-$250 per fixture. Estimate jobs by combining linear-foot rates with per-register charges for a practical quick quote.
Assumptions: includes connectors, tape, basic insulation, typical number of fittings.
Primary Variables That Change The Final Quote
Access difficulty increases labor: tight attic access or fragile insulation can add $500-$2,000. Duct material grade and insulation: moving from flex to custom sheet metal raises material cost by $6-$12 per ft. Major price swings occur when the run length exceeds 300 linear feet or when attic access requires extensive safety equipment or removal of obstacles.
Two niche drivers: replacing ducts for multi-zone systems often adds 20–40% due to balancing and additional dampers; switching to sealed R-8 foam-insulated ducts can add $3-$8 per ft versus standard insulated flex.
Smart Ways To Lower Attic Duct Replacement Price
Scope-control tactics: replace only leaking or undersized branches instead of entire system; repair and seal existing trunks when feasible. Choosing standard insulated flex over custom sheet metal can cut material costs by 30–50%. Preparing the attic—clearing pathways and removing old insulation around work areas—can shave labor time and reduce the quote by several hundred dollars.
Regional and Seasonal Price Differences For Attic Duct Work
Prices are usually 10–25% higher in urban coastal markets (West Coast, Northeast) than in the Midwest or South. Peak HVAC seasons (late spring, early fall) can raise labor rates or lead times, adding $200-$800 to final price. Scheduling work in shoulder seasons and getting multiple quotes helps lock in lower labor rates.
Extra Charges, Add-Ons, And When Permits Matter
Common extras: duct testing/blower-door verification $150-$400, adding motorized dampers $150-$400 each, and sealing with mastic vs. tape adds $200-$600. Permits or inspections may be $0-$300 depending on local code when ducts are part of major HVAC changes. Expect additional costs when the job requires balancing, code upgrades, or replacing gas flues or roof curbs encountered during work.
Three Real-World Quote Examples With Specs and Pricing
| Scenario | Specs | Labor Hours | Total |
|---|---|---|---|
| Small cottage | 650 sq ft, 120 ft flex replace, 6 vents | 6–10 hours | $1,200-$2,200 |
| Average suburban home | 1,900 sq ft, 300 ft mixed flex+sheet, 10 vents | 12–24 hours | $3,800-$6,200 |
| Large home with custom trunks | 2,800 sq ft, 450 ft custom sheet metal, zoning | 24–40 hours | $6,000-$9,500 |
These examples illustrate how scope and material choice change labor hours and totals; request line-item quotes to compare materials, labor, and testing fees.