Ductwork Replacement Cost

Ductwork replacement cost runs about $1,400 to $7,000 for a typical home, with an average near $3,500. Accessible flex or spiral duct commonly costs $9 to $25 per linear foot installed. Rigid sheet metal, crawl-space access, finished ceilings, asbestos, or a full redesign can push a large project past $10,000.

The useful estimate is the one tied to scope. Count the runs and returns, identify where crews can reach them, decide whether the job is replacement or redesign, and make every contractor price the same work. Keep those measurements and quote notes in My Plan.

Ductwork replacement cost at a glance

• Most homes pay $1,400–$7,000, while large or difficult whole-home projects can reach $10,000–$20,000.
• Accessible flex or spiral duct commonly runs $9–$25 per linear foot installed. Custom sheet metal runs about $20–$60+.
• Ductwork cost is mostly about access and complexity (where ducts are, how finished the space is, and how many runs and returns are needed).
• Full replacement isn’t always the right move. Sometimes sealing, repairs, or balancing gets you the comfort outcome cheaper.
• The best quotes specify scope + verification (airflow targets, balancing, duct sealing plan), not just “new ducts.”
• A “cheap duct quote” is often missing returns, balancing, or realistic access work.

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How much does it cost to replace ductwork?

Use the home-size ranges as a starting point, then adjust for access and material. A compact house with open basement runs can land below the range. A tight crawl space or ducts hidden behind finished ceilings can push the same amount of material far above it.

These ranges assume flex or spiral duct, removal of accessible old runs, new boots and registers, sealing, insulation, and basic airflow verification. Drywall repair, painting, mold work, and asbestos abatement are usually separate.

Choose the ductwork replacement scope

Write down the outcome you want (comfort? noise? air quality? efficiency?) before you compare bids.

Estimate your HVAC ductwork replacement cost

You do not need perfect measurements. You need consistent assumptions so each contractor prices the same system.

A) Home and access factors

• Home size (rough): small / medium / large
• Stories: 1 / 2 / 3+
• Duct location: attic / crawlspace / basement / inside walls/soffits
• Access difficulty: easy / moderate / difficult (finished ceilings, tight crawl, high attic heat)

B) Duct system complexity

• Number of supply registers (rough count)
• Number of returns (rough count)
• Any rooms with chronic issues (list them)
• Any known duct problems (leaks, crushed ducts, old flex, undersized returns)

C) “Verification” expectations

Decide if you want:

• Airflow/balancing verification (recommended for comfort complaints)
• Before/after leakage measurement (if available)

Put your notes in My Plan so every contractor is quoting the same scope goal:
My Plan

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HVAC ductwork replacement cost factors

Access and crawl-space work

Replacing ducts in an open basement is not the same project as replacing ducts buried in finished ceilings or tight chases.

The cost to replace ductwork in a crawl space often runs $3,000 to $7,300 because low clearance slows removal, hanging, sealing, and insulation. Ask whether the quote includes disposal and vapor-barrier repairs before comparing it with an attic or basement bid.

Returns, the missing line item

Comfort problems often trace back to inadequate return air. Good scopes address:

• Return locations
• Return sizing
• Door undercuts/transfer grilles where needed

Design versus like-for-like replacement

Some contractors replace ducts exactly as-is. That can lock in old problems.

Ask: “Are you redesigning for airflow, or copying the existing layout?”

Balancing and close-out

If you want comfort, you want balancing. If balancing isn’t included, the system can still feel wrong after replacement.

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Sanity-check table: what should be in a “good” duct quote

• A sketch or description of new supply/return layout
• Materials specified (flex vs metal, insulation, sealing approach)
• Access plan (what will be opened, what will be repaired)
• Balancing/verification plan (how they’ll confirm airflow distribution)
• Clear exclusions (patching, drywall, painting, asbestos concerns, etc.)

Printable ductwork quote checklist

• Are you replacing, sealing, or redesigning? Why?
• How many supplies and returns are included?
• Are you adding returns or transfer pathways where needed?
• How will you verify the result (balancing, airflow checks)?
• What finish work is included/excluded (drywall/paint)?

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If you only do 3 things

1. Decide the scope level (repair vs sealing vs partial vs full replacement).
2. Ask about returns (they’re often the comfort bottleneck).
3. Require verification (balancing/airflow checks) if comfort is the goal:
   My Plan

Four examples (how scope changes the quote)

Beginner example #1: One room always hot/cold

Often a targeted fix (return pathway, crushed duct, balancing) solves it without full replacement.

Beginner example #2: Old flex ducts in a hot attic

A partial replacement plus sealing and better insulation might deliver comfort without a full redesign.

Pro example #1: Finished ceilings hide duct problems

Access becomes the cost driver. A staged plan can reduce disruption.

Pro example #2: Full replacement paired with a new heat pump

Best practice is to coordinate sizing, airflow targets, and commissioning so the new HVAC actually performs.

Edge cases (when you should pause)

• Suspected asbestos or unsafe materials. Consult appropriate professionals before demolition.
• You’re replacing ducts to “fix” dust. Duct replacement won’t solve source issues without filtration and sealing strategy.

Common mistakes to avoid

• Buying “new ducts” without returns, balancing, or verification
• Comparing quotes that assume different access and finish work
• Replacing ducts without addressing the airflow design problem

Troubleshooting: “I replaced ducts and it’s still uncomfortable”

Check:

• Returns and return pathways (doors, transfer)
• Register placement and obstructions
• Balancing (was it done?)
• Envelope leaks that overwhelm HVAC

Sources & further reading

• U.S. Department of Energy — Duct sealing and efficiency basics: https://www.energy.gov/energysaver/duct-sealing
• ENERGY STAR — Heating and cooling guidance: https://www.energystar.gov

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About this post: We wrote this to give homeowners a simple way to compare ductwork quotes based on scope and verification. For safety and code compliance, use licensed HVAC professionals for duct system work.