Ductwork Cost & Lifespan (Halifax, 2026)

Galvanized sheet metal trunk duct and branch takeoffs running between floor joists in an unfinished basement

"How much does ductwork cost?" is a fair question with an annoying answer: it depends more on your house than on your ducts. The metal itself is a modest share of the bill. What actually sets the price is how hard it is to get to — and that's why online calculators and real quotes so often disagree.

Still, "it depends" is not useful when you're trying to budget. So here are real ranges, what moves them, how long ducts actually last, and — the question that saves people the most money — how to tell whether you need replacement at all.

Everything below is a planning estimate, not a quote — drawn from Canadian cost data as of mid-2026. Prices move with material costs, and the scope of your specific project determines the actual cost. We've deliberately framed these toward the higher end: we'd rather you budget generously and come in under than plan around a best-case number and get caught short.

What ductwork actually costs

Two ways to look at the number, both useful.

By the linear foot, which is how duct is actually priced:

Insulated flexible duct — roughly $15–$25 per linear foot installed.
Rigid galvanized sheet metal — roughly $30–$45 per linear foot installed.

Sheet metal costs more up front and lasts far longer, which is most of the argument for it.

By the whole job, published figures for a 1,500 sq ft home tend to cite $4,500–$7,500 for a full replacement. Take that as the easy-access floor, not the expected price. It assumes an open basement and a cooperative layout. Once you're working through finished ceilings, across multiple storeys, or adding returns that were never there, $8,000–$12,000 or more is a more realistic planning figure — and a large or genuinely difficult house can exceed it. Where a home has no ducts at all and a system goes in from scratch, the combined equipment-and-ductwork figure can reach $15,000 or more.

Roughly 30–40% of the bill is labour, with materials making up most of the rest. That ratio is the tell: you're largely paying for time in awkward spaces, not for steel — which is exactly why the same duct costs very different amounts in two different houses, and why no honest number exists before someone has seen yours.

What drives your number up or down

Two houses the same size can quote thousands apart. The reasons are consistent:

Access. The dominant factor. An open, unfinished basement is quick work. Running new trunk through finished ceilings, closed walls, or a tight crawlspace means opening things up, working in constrained space, and repairing afterward.
Layout and storeys. A single-storey ranch on a slab-free basement is straightforward. Getting supply and return to a third floor is not.
How much is custom. Standard fittings are cheap. Odd angles, tight joist bays, and awkward transitions need custom-fabricated pieces — better results, more shop time.
Returns. Older homes are chronically short on return air. Adding returns where none exist means new runs and new grilles, and it's frequently the difference between a system that works and one that doesn't.
Material choice. Sheet metal over flex, insulation levels, and sealing method all move the total.
What's behind the walls. In pre-1980s homes, old duct insulation and tape can contain asbestos. If it turns up, it's licensed abatement work that has to happen separately, by a specialist, before duct work continues. We don't do abatement — but we'll tell you straight if we think you're looking at it.

How long ductwork actually lasts

Lifespan is mostly a material question, and the spread is wide:

Rigid galvanized sheet metal — commonly cited at 25 years, and in practice often well beyond it. It doesn't rot, doesn't mould, and doesn't degrade on its own. Sheet metal that was installed properly in a dry basement can still be doing its job decades later.
Insulated flexible duct — more typically 10–15 years. The inner liner tears, insulation compresses, and long unsupported runs sag into airflow-killing curves.
Duct board / fibreglass — shorter still, and vulnerable to moisture damage.

The honest summary: age alone is a weak reason to replace metal ductwork. If a contractor's opening argument is "it's twenty years old," ask what they actually found. Condition and sizing are the real criteria.

When ducts genuinely need replacing

The signals that matter:

Rust, corrosion, or moisture damage — particularly in a damp basement or crawlspace.
Crushed, collapsed, or disconnected runs — a section that came apart is dumping conditioned air into a joist bay.
Sagging flex on long runs, throttling airflow with every curve.
Undersized for the system — the big one in retrofits. Ducts sized for an oil furnace often can't move the volume a heat pump needs. That's not wear; it's a mismatch, and no amount of good condition fixes it.
Missing returns, which starve the system no matter how good the supply side is.
Persistent symptoms — rooms that never warm up, high bills, whistling, dust — that survive sealing and balancing.

The middle ground most homes actually need

Here's the part that saves money: full replacement is the exception, not the rule.

Most houses need targeted work — sealing the leaky joints, replacing the few sections that have failed, resizing an undersized trunk, adding the return that was never there. That's a fraction of a full replacement and it fixes the majority of real complaints. Duct sealing alone addresses a surprising share of comfort problems, since a typical system leaks 20–30% of the air it moves.

Full replacement earns its cost in a few clear cases: the system is undersized throughout, corrosion is widespread, the layout is fundamentally wrong, or the ducts are being rebuilt anyway as part of a furnace conversion. Outside those, partial rework is usually the better buy — and if someone quotes a full replacement without walking your system first, get a second opinion.

The full catalogue of what tends to be wrong is in our guide to common ductwork problems in older Halifax homes.

The Halifax wrinkle: conversions

A lot of local duct spending right now isn't about worn-out ducts at all — it's about changing systems. Halifax has a large stock of postwar homes built around oil furnaces, and when those convert to a heat pump, the ductwork question arrives with it.

An oil furnace pushes small volumes of very hot air. A heat pump moves larger volumes of cooler air, which needs more duct capacity and considerably more return. Ducts that served the furnace faithfully for forty years can be genuinely undersized for the new equipment — in good condition and still wrong for the job. That's the single most common reason a Halifax homeowner gets a ductwork quote in 2026. There's more on that specific job in our oil furnace to heat pump conversion guide and on ductwork sizing for ducted heat pumps.

Worth knowing before you budget: rebate programs are aimed at the equipment, not the air side. The duct work usually sits outside what they cover, so scope it early rather than discovering the gap after the heat pump is ordered.

Getting a quote worth trusting

A few things separate a real quote from a number:

They looked at the whole system, not just the piece you complained about.
They measured or calculated, rather than eyeballing what "should" fit.
They checked the returns, not only the supply side.
They told you what you don't need. A contractor who talks you out of the expensive option when the cheap one will work is showing you how they'll behave later.
The scope is written down — what's being replaced, what's being sealed, what's being left alone. Scope is the price; a number without a scope attached isn't a quote, it's a guess.

Where we fit in

Ductwork is our trade, so we'll give you the straight version: most homes we look at need less than they expect, and the ones that need more usually need it for sizing reasons, not age. We assess what's there, tell you honestly what it needs, and quote the air side clearly — resizing, sealing, returns, transitions, and custom fabrication where the layout calls for it. Refrigerant work and commissioning go to our licensed heat-pump partners; the air side is ours.

And to say it once more plainly, because it's the honest bottom line on any cost article: every figure here is an estimate. The scope of the work — how much duct, how accessible, what has to be opened up, what the new system actually demands — is what determines the cost. If you want a real number for your house rather than a range from the internet, get in touch. A look at the system is what turns "it depends" into a figure you can budget against.

Related services

Frequently asked questions

How much does it cost to replace ductwork?

Treat any figure you read as an estimate, not a quote — the scope of the specific project is what sets the cost. That said, for planning: a full replacement in a typical 1,500 sq ft Canadian home commonly starts around $4,500–$7,500 where access is easy, and realistically runs $8,000–$12,000 or beyond once finished walls, multiple storeys, added returns, or custom transitions come into it. We'd rather you budget toward the higher end and be pleasantly surprised than plan on the lowest number online and get a shock. The material is a smaller share than people expect — roughly $15–$25 per linear foot for insulated flex, $30–$45 for galvanized sheet metal, with labour 30–40% of the bill. The biggest swing factor isn't the duct, it's how hard your house is to work in.

How long does ductwork last?

It depends heavily on the material. Rigid galvanized sheet metal is the durable option — commonly quoted at 25 years and routinely still doing its job well beyond that, because it doesn't rot, mould, or degrade. Insulated flexible duct is the shorter-lived one, more typically 10–15 years, since the inner liner tears, the insulation compresses, and long sagging runs choke off airflow. A general rule: if your ducts are rigid metal, age alone isn't a reason to replace them. If they're flex and over 15, they're worth inspecting.

Should ductwork be replaced after 20 years?

Not automatically, and we'd be suspicious of anyone who says otherwise without looking. Twenty-year-old galvanized sheet metal in a dry basement is often in genuinely good condition and has decades left. What actually triggers replacement is condition and fit, not birthdays: rust or crushed sections, joints that have come apart, or ducts that are simply the wrong size for the system you're putting in. Plenty of older Halifax homes need their ducts reworked because a heat pump needs more airflow than an oil furnace did — that's a sizing problem, not an age problem.

Is it cheaper to repair ductwork or replace it?

Repair, almost always — and it's the right answer more often than people expect. Sealing leaky joints, replacing a few crushed or disconnected runs, and adding a missing return costs a fraction of a full replacement and fixes most real-world complaints. Full replacement earns its cost when the system is undersized throughout, badly corroded, or being rebuilt anyway for a furnace conversion. An honest contractor should tell you which category you're in before quoting the expensive one. Either way the figure depends on scope — how much duct, how accessible, and what has to be opened up to reach it.

What makes ductwork cost more than the quote I saw online?

Access, mostly. Online figures assume an open, workable basement. Costs climb when ducts run through finished ceilings and walls that have to be opened and repaired, when the house has multiple storeys or a tight crawlspace, when the layout needs custom-fabricated transitions rather than off-the-shelf fittings, and when returns have to be added where none exist. In older homes, discovering asbestos-containing materials around old duct insulation or tape also changes the job — that's specialist abatement work that has to be handled separately before duct work continues.

Does new ductwork come with the heat pump quote?

Usually not the full cost of it, and this is where budgets get blown. Heat-pump quotes are built around the equipment, and the air-side work your ducts may need — resizing, sealing, added returns, a new plenum transition — is often quoted thinly or assumed away. Rebate programs generally target the equipment, not the ductwork. Get the duct side scoped separately and early so you're budgeting the whole project rather than discovering the gap after the equipment is ordered.

How Much Does Ductwork Cost — and How Long Does It Last?