Ductwork Replacement Cost Add-On Calculator
Adding ductwork replacement to your HVAC project can add $500 to $12,000 to total costs—but may be essential for comfort and efficiency. This guide helps you estimate ductwork costs separately from equipment so you can budget accurately.
Quick Answer
Ductwork replacement costs $500 to $12,000 depending on scope:
| Ductwork Scope | Cost Range | When Needed |
|---|---|---|
| Duct sealing only | $500 - $1,200 | Leakage under 20%, ducts in good condition |
| Minor repairs/sections | $1,000 - $3,500 | Localized damage, disconnected joints |
| Main trunk replacement | $2,000 - $5,000 | Collapsed or severely undersized trunk |
| Full duct system | $4,000 - $12,000 | Asbestos, total redesign, or 40%+ leakage |
Add 20-50% for accessibility challenges (attic, crawlspace, wall cavities).
What Drives Ductwork Costs
Accessibility
The harder ducts are to reach, the more you pay:
| Location | Cost Impact |
|---|---|
| Open basement/crawlspace | Base pricing |
| Tight crawlspace | +20% to +40% |
| Attic installation | +25% to +50% |
| Wall cavities (retrofit) | +50% to +100% |
Materials
- Flexible duct (easiest to install): $8-$15 per linear foot installed
- Sheet metal (most durable): $15-$25 per linear foot installed
- Ductboard (quiet, mid-range): $12-$20 per linear foot installed
Home Size
Larger homes require more ductwork:
- 1,000-1,500 sq ft: 50-80 linear feet of ductwork
- 1,500-2,500 sq ft: 80-120 linear feet of ductwork
- 2,500+ sq ft: 100-160+ linear feet of ductwork
When Ductwork Replacement Is Worth It
Replace ductwork if you have any of these conditions:
- Leakage exceeds 20-25% (confirmed by duct blaster test)
- Visible damage: crushed sections, disconnected joints, mold growth, or rodent infestation
- Undersized ducts causing noise, poor airflow, or short cycling
- Major renovation changing floor plan or HVAC system type
- Asbestos tape on duct joints (common in 1970s-1980s homes)
Bundled vs. Separate Replacement
| Approach | Pros | Cons |
|---|---|---|
| Bundle with HVAC replacement | Single project, coordinated labor, may include extended warranty | Higher upfront cost |
| Defer ductwork | Lower immediate expense | Reduced efficiency, may void equipment warranty, second disruption later |
Decision Framework
If duct leakage testing shows 25%+ loss or you have visible damage, include ductwork in your HVAC project. The efficiency gains (5-15% on utility bills) plus comfort improvement typically justify the cost within 5-8 years.
Timeline Expectations
- Duct sealing only: 2-4 hours
- Section replacement: 1-2 days
- Full duct system: 2-4 days (depending on home size and accessibility)
FAQ
How do I know if my ducts need replacement?
Schedule a duct leakage test (duct blaster). If leakage exceeds 20-25% of total airflow, or if you see visible damage, replacement is typically warranted.
Is this an exact quote?
No. This is a planning estimate. Final pricing depends on contractor rates, material costs in your area, and home-specific factors like accessibility and existing duct condition.
Can I replace ductwork without replacing my HVAC system?
Yes. If your HVAC equipment is in good condition but ductwork is leaking or undersized, standalone ductwork replacement is possible. Get quotes from HVAC contractors who specialize in ductwork.
Does ductwork replacement require permits?
In most jurisdictions, yes. Permit costs typically range from $100-$500 and should be included in contractor quotes. Work with a licensed contractor who handles permitting.