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1How Much Does Radon Mitigation Cost in Canada?
Last updated: By RadonIndex Research Team
A standard sub-slab depressurization system costs $2,000 to $3,000 for material and labour under the Health Canada Reduction Guide range reported by Homeowner.ca, and $2,000 to $4,000 installed across Canada with a national average near $2,900. Crawl spaces, mixed foundations and difficult pipe routes push a job toward the $4,000 to $10,000 band RenoQuotes publishes for complex installations.
What does each type of radon system cost?
The 7 prices below rest on 2 independent published sources, and every figure was re-read in the source it names before this page went up. Where a figure could not be found in the source credited with it, the row was removed rather than repaired, so a narrow range here means the evidence is narrow.
| Item | Typical range | Unit | Source |
|---|---|---|---|
| Sub-slab or sub-membrane depressurization system, material and labour | $2,000–$3,000 | installed | Homeowner.ca |
| Radon mitigation system, typical Canadian home | $2,000–$4,000(typ. $2,900) | installed | Homeowner.ca |
| Sump or drainage system depressurization | $2,000–$4,500 | installed | RenoQuotes |
| Crawl space sub-membrane depressurization | $3,000–$6,000 | installed | RenoQuotes |
| Complex or multi-system installation | $4,000–$10,000 | installed | RenoQuotes |
| HRV or ERV ventilation as a radon measure | $1,500–$3,500 | material and labour | Homeowner.ca |
| Radon fan replacement, fan only | $200–$300 | per fan | Homeowner.ca |
What drives the price?
Site access, the amount of prep and the material grade move radon mitigation pricing more than anything else in Toronto. Each factor below comes from the same sources as the table, so you can read a quote and see where the money goes.
- Foundation type. One slab with accessible routing sits at the bottom of every published range; mixed foundations, crawl spaces and multiple slabs climb.
- Where the pipe can run. An exterior route down a side wall is cheaper than chasing a pipe through a finished basement to the roofline.
- Whether the house already has a rough-in. RenoQuotes notes that activating an existing rough-in is often less than a full retrofit.
- Post-installation testing. A re-test after the system is running is the only proof the work succeeded, and not every quote includes it.
What's specific to Ontario and Toronto?
Ontario adds 13% HST to this work, and the province has one rule no national price guide carries: new homes here have radon coverage under the Tarion warranty. Confirm the current terms with Tarion before assuming it applies to you.
- Ontario new homes carry radon coverage under the Tarion warranty. If a certified test reads at or above the Health Canada guideline, mitigation can fall to the builder. Confirm the current terms with Tarion directly before relying on this.
How can I pay less?
Booking off-season, bundling neighbouring properties and reusing a sound existing base are the three levers that cut a radon mitigation bill without touching the parts that matter. Each one below is tied to a real number in the table above.
- Test properly before you buy anything. A short screening test cannot justify a $3,000 system.
- Ask whether the quote includes a post-mitigation test. If it does not, price that separately before comparing bids.
- Ask what the fan warranty covers and how long it runs, since the fan is the only moving part.
How did we research these numbers?
Every price on this page comes from a named Canadian source, and where sources disagreed we widened the range rather than pick a favourite. Here is how RadonIndex reconciled the numbers.
- Every figure on this page is a published Canadian range, not a quote from any company listed on this site. We hold no pricing from GTHA mitigators, and we do not estimate one.
- Health Canada guidance is to act above 200 Bq/m3. The World Health Organization uses 100 Bq/m3. Neither number is a safety threshold: risk falls continuously as the level falls.
- A mitigation quote is only meaningful after a long-term test. A three-month minimum during the heating season is the measurement Health Canada asks for.
Sources
Who can do the work?
RadonIndex lists 12 radon mitigation contractors across the Greater Toronto and Hamilton Area, rated 4.87★ on average across the 9 with three or more reviews. The three below rank highest on the RadonIndex Score described on our methodology page (August 2026 data). None of them set the prices above.
- R2
- M3
What do the terms on a radon mitigation quote mean?
These are the words that appear on a radon mitigation quote and decide what you are actually being charged for. Each one is defined the way a contractor uses it.
- Sub-slab depressurization
- The standard fix. A pipe is cut through the basement floor slab into the gravel beneath it, and a fan draws soil gas up the pipe and out above the roofline before it can enter the house.
- Suction point
- One hole through the slab where the system pulls from. A straightforward basement needs one; several slabs or poor sub-slab gravel can need more, and each one adds cost.
- Radon rough-in
- A capped pipe built into a newer home so a system can be added later. It is not a working system on its own, but activating one is usually cheaper than a full retrofit.
- Backdrafting
- When a depressurization system pulls combustion gases back down a furnace or water heater flue instead of letting them vent. A competent installer tests for it after commissioning.
- Post-mitigation test
- A fresh radon measurement taken after the system is running. It is the only proof the work succeeded, and not every quote includes it.
What else should I price before deciding?
Radon Mitigation is rarely quoted on its own. These guides cover the work most often bought alongside it, each researched the same way and priced from named sources.
Frequently asked questions
How much does radon mitigation cost in the GTHA?
- No published figure is specific to the Greater Toronto and Hamilton Area, so we do not print one. The Canada-wide ranges are $2,000 to $3,000 for a standard sub-slab depressurization system per the Health Canada Reduction Guide, and $2,000 to $4,000 installed with a national average near $2,900 per Homeowner.ca. Get at least two written quotes from C-NRPP certified mitigators.
Why is there such a wide spread between quotes?
- System complexity. A single suction point in an accessible basement with good sub-slab gravel sits at the low end. Mixed foundations, crawl spaces, several slabs or a difficult pipe route move a job into the $4,000 to $10,000 band RenoQuotes publishes for complex installations.
Is a cheaper option than a full system worth it?
- Sealing cracks alone rarely solves the problem, because it is close to impossible to find and seal every opening. HRV or ERV ventilation is rated at a 25 to 50 percent reduction against 80 percent or better for active depressurization, so it is a supplement rather than a fix.
Questions to ask your contractor
- What is your C-NRPP certificate number, and is the certified person the one doing the work?
- Does the quote include a post-mitigation test to prove the level actually dropped? What a re-test costs
- How many suction points are you pricing, and what happens if one is not enough? Why suction points move the price
- Where will the pipe run and where does it discharge relative to windows and the roofline?
- Will you test for backdrafting of the furnace and water heater once the fan is running?
- What is the warranty on the fan, and what does it cover after year one?