Sealing cracks and controlling water also helps radon work; to price exterior or interior waterproofing, use our foundation waterproofing cost calculator.
Official sources checked on November 10, 2026.
The radon mitigation system cost in Canada is usually a few thousand dollars installed. Health Canada’s radon reduction guide puts the most common method, sub-slab depressurization, at about $2,000 to $3,000 including material and labour, while Take Action on Radon reports $3,000 to $11,000 for recent systems (average of about $2,700 for systems installed from 2013 to 2021). Budget about $50 to $75 a year for the fan’s electricity; in Ontario, add 13% HST to quotes, and eligible households can apply for up to $1,500 from the Lungs Matter program.
Want a figure for your own house? Our basement renovation cost calculator has a separate radon mitigation line with Ontario, Québec and B.C. prices (before tax), so you can add it to the rest of your basement budget.
In this guide
Radon mitigation system cost at a glance
These are the numbers that matter before you call a contractor. Official figures come first; commercial prices are only a cross-check.
| Item | Typical cost or figure | Source (date) |
|---|---|---|
| Sub-slab depressurization (most common method) | About $2,000 to $3,000, material and labour | Health Canada radon reduction guide (February 2023) |
| Systems in recent Canadian data | $3,000 to $11,000; average about $2,700 (2013 to 2021 installs) | Take Action on Radon (January 2026) |
| Standard detached home, published Canadian prices | About $2,000 to $4,000; complex jobs $4,000 to $6,000 or more | Three Canadian contractor and price-guide sources, July to August 2026 |
| Sealing cracks and openings (support only) | A few hundred dollars to $2,000 or more | Health Canada guide (2023) |
| Heat recovery ventilator (HRV) | $1,500 to $3,500, material and labour | Health Canada guide (2023) |
| Fan electricity | About $50 to $75 a year | Health Canada guide (2023) |
| Replacement fan | $200 to $300; fans last 5 to 10 years or more | Health Canada guide (2023) |
| Long-term radon test kit | About $45 to $70, plus possible lab fees | York Region (October 2025) |
| Installation time | Less than a day in most homes | Health Canada (September 2026) |
Why the official ranges differ: Health Canada’s guide gives a typical price for one method, while Take Action on Radon summarizes hundreds of real installations, including large or complicated homes. Its own average (about $2,700) sits below its current range because it covers older installs. For a standard detached house with one suction point, the $2,000 to $4,000 band is the realistic starting point in 2026.
How a radon mitigation system works (and what you are paying for)
A mitigation system pulls radon out of the soil under your house before it can seep in, and sends it outside. According to Health Canada’s page on reducing radon (updated September 22, 2026), the most common method is sub-slab depressurization, it can be installed in less than a day, and it will cut radon by more than 80% in most homes.
A typical quote for a standard system covers:
- One suction point: a hole through the basement slab (or a connection to the sump pit or an existing rough-in pipe).
- Pipe from that point to the outside, routed inside the house or along the exterior wall.
- An in-line fan that runs all the time to keep slight suction under the slab.
- A pressure gauge (often a U-tube manometer) so you can see that the system is working.
- Sealing of the main openings in the slab and around the sump.
- A post-mitigation test, if the contractor includes it (ask: many do not).
If you have not tested yet, start there: a mitigation quote only makes sense once a long-term test shows a result above 200 Bq/m³. Our radon test guide explains how to run a 3-month test and read the result.
Radon mitigation cost by method
Active soil depressurization is the method Health Canada calls the most effective and reliable. The others either suit a particular foundation (crawl spaces, sumps) or only help a little.
| Method | When it is used | Cost (official) | How much it helps |
|---|---|---|---|
| Sub-slab depressurization | Basement or slab-on-grade with a concrete floor | About $2,000 to $3,000 | More than 80% reduction in most homes |
| Sub-membrane depressurization | Crawl space with a dirt or gravel floor: a plastic membrane is sealed down and a fan pulls from under it | Included in the $2,000 to $3,000 range for sub-slab and sub-membrane systems | Same principle as sub-slab |
| Sump or drain tile connection | Homes with a sump pit or weeping tile; the sump gets an airtight cover | Not given separately by Health Canada | Depends on how well the drain tile reaches under the slab |
| Sealing cracks and openings | Always done as part of a system | A few hundred dollars to $2,000 or more | Not a standalone fix, says Health Canada |
| Heat recovery ventilator | Homes that need more fresh air anyway | $1,500 to $3,500 | About 25 to 50% in most homes; limited |
Source: Health Canada, Radon Reduction Guide for Canadians (publication date February 2023). The ranges are not adjusted for inflation, which is one reason recent installs often land higher.
RénoClair tip
If your sealing or HRV quote promises to “solve” a high radon result on its own, ask for a second opinion. Health Canada says sealing is not a standalone technique and that ventilation has limited effect; a fan-driven depressurization system is the reliable fix.
What pushes the price up or down
Two houses with the same radon level can get very different quotes. The main reasons:
- An existing rough-in pipe. Ontario’s 2024 Building Code requires a radon rough-in pipe in all new homes, according to the HCRA homeowner guide (October 2025). If the rough-in already runs outside, the guide says it is easy to add a fan to make it an active system. Without one, a contractor will likely cut a hole in the slab or use the sump pit.
- How many suction points. A tight, uniform gravel layer under the slab may need one; a large footprint, an addition or a split foundation can need two or more.
- Finished basement. Drywall, flooring and built-ins make it harder to find a spot for the pipe and to seal openings.
- Pipe route. Interior routes through closets or a garage are tidier but need more carpentry; exterior routes are simpler but more visible.
- Crawl spaces. Laying and sealing a membrane takes time and can add to the bill.
- Electrical work. The fan needs power near its location; if there is no outlet or circuit there, expect an electrician’s charge.
Planning other basement work? Do the radon system first, then insulate and finish. Our basement insulation guide covers the wall and floor choices, and any big renovation is a good reason to retest afterwards.
Running costs after installation
The fan runs around the clock, so a mitigation system has a small but permanent cost. Health Canada’s guide gives three figures to plan with:
- Electricity: approximately $50 to $75 a year.
- Fan life: five to ten years or more.
- Replacement fan: $200 to $300.
Your actual electricity cost depends on the fan’s wattage and your utility rates, so treat $50 to $75 as an estimate, not a bill. Glance at the manometer every season; if the liquid levels become even, the fan has likely stopped. Our winter home maintenance checklist is a good place to add that check.
Worked example: 10-year cost of a radon mitigation system in Ontario
Scenario: a detached house in Ontario. A 3-month test reads 350 Bq/m³ in the basement family room. A C-NRPP certified professional quotes a single-point sub-slab system for $3,000 before tax (inside the published $2,000 to $4,000 band). We compare it with a complex job at $6,000 (two suction points and a finished basement). Assumptions: 13% HST on the system, the replacement fan and test kits; the high end of Health Canada’s electricity estimate ($75 a year, entered as given, without adding tax); one fan replacement at $300; two long-term test kits at $70 (after installation and at the five-year retest).
| Cost over 10 years | Standard system | Complex system |
|---|---|---|
| System, with 13% HST | $3,390.00 | $6,780.00 |
| Fan electricity (10 × $75) | $750.00 | $750.00 |
| One replacement fan ($300 + HST) | $339.00 | $339.00 |
| Two long-term test kits ($70 + HST each) | $158.20 | $158.20 |
| Total over 10 years | $4,637.20 | $8,027.20 |
| Average per year | $463.72 | $802.72 |
| Total if Lungs Matter pays the maximum $1,500 | $3,137.20 | $6,527.20 |
What the example shows: the installation is most of the cost. Over 10 years, running and retesting add $1,247.20 in both cases, so the complex job ends up $3,390.00 more than the standard one, exactly the difference in the taxed installation price. If you qualify for the full Lungs Matter amount, the standard system costs $1,890.00 up front after the grant.
Redo this calculation with your own basement in our basement renovation cost calculator. Its Ontario radon line ($1,600 to $3,800 before tax, November 2026) also covers a sump pump with battery backup, so it starts lower than the official ranges above; use it for planning, and rely on a certified quote for the real number.
When you need to mitigate: Health Canada’s timeline
The Canadian guideline is 200 Bq/m³ as an annual average. Health Canada’s Guide for radon measurements in homes (updated May 22, 2026) says to mitigate within one year when radon is higher than 200 Bq/m³, and sooner if the level is higher. C-NRPP gives the same one-year advice.
- Older documents still show a two-year tier. The 2023 radon reduction guide and some municipal pages still say 200 to 600 Bq/m³ can wait up to two years. The current measurement guide does not; plan on one year.
- US numbers are not the Canadian guideline. 37 Bq/m³ equals 1 pCi/L, so a US report in pCi/L needs converting before you compare it with 200.
- Base the decision on a long-term test. C-NRPP calls a test of 91 days or more best practice; short tests are for checking a new system, not for deciding whether you need one.
For the French-language guide aimed at Québec, see our radon detector article (in French).
Help with the cost in Ontario
Lungs Matter radon mitigation support
The Canadian Lung Association’s Lungs Matter program (page updated October 16, 2026) offers up to $1,500 towards home radon mitigation. To be eligible you must have been diagnosed with lung cancer or be from a low- or moderate-income household; in Ontario, total household income must be no more than $105,100. You need long-term results (at least 90 days) above 200 Bq/m³ from a C-NRPP certified test kit and a quote from the C-NRPP certified professional who will do the work.
- Apply before the work: the program is for mitigations that have not already been completed.
- Funding is limited, and meeting the criteria does not guarantee a grant; priority goes to low-income households.
Tarion warranty for newer homes
If you bought a new home in Ontario under a purchase agreement signed on or after February 1, 2021, Tarion’s warranty covers remediation of radon above 200 Bq/m³ for up to seven years, within a limit of up to $50,000 for environmental hazards. Both the test and the remediation must be done by C-NRPP certified professionals. Contact your builder first, before paying for a system yourself.
What the 2024 Ontario Building Code changed
New homes must now include a capped, sealed and labelled radon rough-in pipe, according to the HCRA guide. The code does not require builders to test, and it does not install a fan: testing is up to the homeowner. HCRA says the updates came into full effect in April 2025; another municipal page gives January 1, 2025, so check with your builder if the date matters for your home.
How to compare radon mitigation quotes
Get two or three quotes and line them up item by item. A good quote answers each of these:
- Is the installer certified by C-NRPP? Health Canada, Tarion and Lungs Matter all point to certified professionals.
- How many suction points, and where will the pipe run (inside or outside)?
- Where exactly will the exhaust discharge outside, and how far is it from windows and doors?
- Which fan model and wattage, and what warranty on the fan and on the work?
- Is a pressure gauge included, and will they show you how to read it?
- Which openings will be sealed (sump, floor drains, cracks, slab edges)?
- Is electrical work included, or will you need an electrician?
- Is a post-mitigation test included, and who pays if the result is still above 200 Bq/m³?
- Does the price include HST?
After installation: retesting schedule
- First check: C-NRPP says a short-term test should start after the fan has run for at least 24 hours and last at least 48 hours.
- Long-term confirmation: Health Canada’s guide recommends a three-month test in the following fall or winter, and an initial long-term test within two years of activating the system.
- Every five years: both Health Canada and C-NRPP recommend a long-term test at least once every five years with a working system.
- After major renovations to the basement or the heating and ventilation system, test again.
Common mistakes that raise the cost
- Paying for a system on the strength of a short-term test or a single digital reading.
- Choosing sealing or an HRV alone when the result is well above 200 Bq/m³.
- Finishing the basement first, then paying extra to open walls for pipe routes.
- Hiring an uncertified installer, which can disqualify you from Lungs Matter or Tarion.
- Forgetting the post-mitigation test, so you never know whether the system worked.
- Ignoring a silent fan: check the gauge each season and budget for a replacement.
Frequently asked questions
How much does a radon mitigation system cost in Canada?
Usually a few thousand dollars. Health Canada lists about $2,000 to $3,000 for sub-slab depressurization, Take Action on Radon reports $3,000 to $11,000 for recent systems, and published prices for a standard detached house are about $2,000 to $4,000 in 2026, before HST. Estimate your own project with our basement renovation cost calculator.
Is radon mitigation worth it?
Yes, if your long-term test is above 200 Bq/m³. Health Canada says a mitigation system reduces radon by more than 80% in most homes, and the work usually takes less than a day.
How long does it take to install a radon mitigation system?
Usually one day or less. Health Canada says less than a day, and C-NRPP says most homes can be mitigated in one day.
How much electricity does a radon fan use?
Health Canada estimates about $50 to $75 a year for the fan’s electricity. Fans last five to ten years or more and cost $200 to $300 to replace.
Can I install a radon mitigation system myself?
Health Canada recommends a C-NRPP certified professional, and both Lungs Matter and Tarion require certified work, so a do-it-yourself system can cost you that help.
Is there a radon mitigation grant in Ontario?
Yes: the Canadian Lung Association’s Lungs Matter program offers up to $1,500 to eligible households, with an Ontario income limit of $105,100. Funding is limited and you must apply before the work is done.
Does Tarion cover radon mitigation?
Yes, for new homes with purchase agreements signed on or after February 1, 2021: remediation of radon above 200 Bq/m³ is covered for up to seven years, within a $50,000 limit for environmental hazards.
How often should I retest after radon mitigation?
Test after the fan has run at least 24 hours, do a long-term test the following heating season, then repeat a long-term test at least every five years.
The bottom line
Plan on roughly $2,000 to $4,000 plus HST for a standard radon mitigation system in Ontario, more for crawl spaces, several suction points or finished basements, plus about $50 to $75 a year to run the fan. Test first, hire a C-NRPP certified professional, check Lungs Matter or Tarion before you sign, and retest after installation and every five years. The basement renovation cost calculator can help you fit the system into your wider basement budget.
Sources
- Health Canada, Reducing radon levels in your home (modified September 22, 2026; read November 10, 2026).
- Health Canada, Radon Reduction Guide for Canadians (publication date February 2023; read November 10, 2026).
- Health Canada, Guide for radon measurements in homes (modified May 22, 2026; read November 10, 2026).
- Take Action on Radon, Reducing radon (modified January 6, 2026; read November 10, 2026).
- Canadian Lung Association, Lungs Matter radon mitigation support (modified October 16, 2026; read November 10, 2026).
- C-NRPP, Steps to reduce radon (undated; read November 10, 2026).
- Tarion, Radon and your warranty (undated; read November 10, 2026).
- HCRA, What every homeowner should know about radon (October 2025; read November 10, 2026).
- York Region, Radon: test your home (modified October 30, 2025; read November 10, 2026).
- Commercial prices: three Canadian contractor and price-guide sources, July to August 2026, used only as a cross-check.
