Replacing ductwork in 2026 typically costs $40 to $65 per linear foot installed, which for a whole single-family home usually lands between $3,000 and $9,000 depending on size, access and material, with difficult crawlspace or attic work, custom metal trunks and added returns pushing toward $12,000; partial replacement of failed runs is proportionally less, and duct sealing (which is what most leaky-but-intact systems actually need) is $500–$3,000. In North Carolina the cost is driven less by material than by where the ducts live: vented crawlspaces and hot attics are where ducts fail and where the work is hardest.
Typical costs
| Job | Typical cost (2026) |
|---|---|
| Per linear foot, installed (flex or basic sheet metal) | $40 – $65 |
| Whole-house replacement, typical single-family | $3,000 – $9,000 |
| Whole-house with new metal trunks / added returns / difficult access | $8,000 – $12,000+ |
| Replace a few failed runs | $500 – $2,000 |
| Duct sealing (mastic / aerosol) instead of replacement | $500 – $3,000 |
When to replace vs seal
Replace when ducts are undersized for the system (high static pressure that sealing won’t fix), crushed or collapsed, disconnected in places you can’t reach, deteriorated (old duct board, rotted insulation, rodent damage), or contaminated with mold. Seal when the ducts are sized adequately and intact but leaky at joints and boots, which describes most homes. A duct leakage test and a static pressure reading tell you which; a contractor who recommends full replacement without either is guessing. Duct sealing vs cleaning.
The North Carolina factors
Crawlspaces: humid, tight, and where flex duct sags, disconnects and sweats; encapsulating the crawlspace at the same time protects the new ducts and improves humidity. Attics: 130°F in summer, so insulation value and sealed connections matter more; consider R-8 flex. Older homes: undersized returns are common; adding returns is often the highest-value duct change. Coast: salt air corrodes metal ducts and boots faster.
What to ask for
A Manual D (or at least room-by-room airflow targets), static pressure before and after, mastic-sealed joints and boots, properly supported and stretched flex, insulated ducts in unconditioned space, and a leakage test at completion. New ducts are usually done alongside equipment replacement, where they’re part of a proper installation. Every contractor on the North Carolina registry shows the license status we found.