Yes, Okanagan homeowners should test their homes for radon because testing is the only way to know the level. Radon cannot be seen, smelled or tasted, and results can vary significantly between neighbouring homes.
Health Canada recommends taking action when the long-term average is 200 Bq/m³ or higher. Use a long-term radon test for at least 91 days—ideally during the heating season—on the lowest level of the home where people regularly spend time.
When I tested my own Okanagan home, the average radon level was approximately 650 Bq/m³ more than three times Health Canada’s guideline. The result surprised me and confirmed why homeowners cannot judge their radon exposure from the home’s age, appearance or a neighbour’s test.
What Radon Is and Why It Matters Here
Radon is a gas produced when uranium in soil and rock breaks down. You can’t see it, smell it or taste it. It moves through the ground, finds its way in through cracks in the slab, sump pits, floor drains, and gaps around plumbing and service penetrations, and it collects in the lowest parts of a house: basements, crawlspaces, and the finished rooms below grade that people use as bedrooms and offices.
Radon is the second leading cause of lung cancer in Canada after smoking. Long-term exposure is what matters, which is why the guideline is set as an annual average rather than a single reading.
The Okanagan sits in an area where high results are common. Health Canada’s 2012 Cross-Canada Survey found 8% of BC homes above the 200 Bq/m³ guideline, with some regions as high as 29%. Community testing since then has found pockets where more than half the homes tested came back over the guideline. Locally, we’ve seen results well over 1,500 Bq/m³ in Kelowna homes.
Your Neighbour’s Result Doesn’t Tell You Anything
Two houses on the same street, built by the same builder in the same year, can test completely differently. What changes the result:
- What’s under the house. Soil type, gravel content, fractured bedrock and how easily gas moves through it.
- The foundation. Full basement, crawlspace, slab on grade, and the number of cracks and openings in it.
- How the house is run. Exhaust fans, dryers and fireplaces pull air out of the house, and some of what replaces it comes up out of the ground.
- Ventilation. A house with an HRV that runs is diluting indoor air. A house without one isn’t.
- The season. Winter results are usually higher than summer results.
So radon gets tested house by house.
What Counts as a Safe Level?
Health Canada’s guideline is 200 Bq/m³, measured as an average annual level in the normal occupancy area of the home. Above that, Health Canada recommends mitigating within a year, and sooner the higher the number is.
There’s no level that’s officially safe. The risk drops as the number drops, so getting a house from 700 down to 60 is a big improvement even though it isn’t zero.
One important detail: the guideline applies to a long-term average, not a short-term reading. A two-day test in July can’t be compared to it.
Our Own Test: 650 Bq/m³
We tested our own house with a long-term kit over the heating season. The 90-day average came back at 650 Bq/m³, more than three times the guideline.
We had no idea until we tested, and we do this for a living. That’s why we bring radon up with homeowners now.
Air Sealing and Radon Go Together
This part matters for anyone doing energy upgrades. When you tighten a house, you reduce the uncontrolled air leakage that used to dilute indoor air. That’s good for your energy bills and your comfort, and it’s what the BC Energy Step Code asks for on new homes. But if radon is coming into the house and the air changes go down, the concentration can go up.
That’s not a reason to skip air sealing. It’s a reason to test, and to make sure the house is ventilated. A new home built to current code has mechanical ventilation, usually an HRV, for exactly this reason. If you’re air sealing an older home, especially a basement, test for radon before and after so you know what happened.
What the BC Building Code Requires
The code has tightened over the years:
- 2012: radon provisions introduced, with a capped rough-in pipe required in designated areas.
- 2014: full soil depressurization requirements in higher risk regions.
- 2024: the regional exemptions were removed. For building permits applied for on or after March 8, 2024, a radon rough-in is required for Part 9 residential buildings across BC, because newer data showed radon turns up everywhere in the province.
A rough-in under the 2024 code means three things: a gas permeable layer under the slab (100 mm of clean coarse granular material in the prescriptive route), a continuous air barrier that’s sealed around the vent pipe, and a 100 mm vent pipe run vertically through conditioned space and out the roof, at least 3 m from any window or air intake.
A rough-in is not a working system. It’s the pipe and the sealed slab that let a system be finished with a fan if your test comes back high. Houses built before 2012 have no radon provisions at all.
When and How to Test
Test during the heating season, and run it for at least 91 days. Winter is when the house is closed up and the stack effect is pulling hardest on the ground under it, so that’s when the results reflect what you’re actually living with. A short summer test will usually read low and give you false comfort.
Put the detector in the lowest level you regularly use, at least 30 cm above the floor, away from exterior walls, drafts, windows and heat sources. Leave it alone and live normally while it runs.
| Option | Typical cost | What you get |
|---|---|---|
| Long-term alpha track kit (91+ days) | $40 to $80 including lab fee | The measurement Health Canada’s guideline is based on. The right choice for a first test. |
| Free kit from a municipality, regional district or library lending program | Free, sometimes with a waitlist | Same long-term test, no cost. Worth checking before you buy one. |
| Digital radon monitor | $200 to $350 | Continuous readings on an app. Good for watching changes and for confirming mitigation, but let it run months before you trust the average. |
| Certified measurement professional (C-NRPP) | Varies | Placement, documentation and interpretation done for you. Often used for real estate deals and for large or complicated buildings. |
What Mitigation Costs
If your result is high, the fix is usually active soil depressurization: a pipe from under the slab, sealed floor penetrations, and a fan that runs continuously and vents above the roof, so the gas gets pulled out from under the house instead of being drawn in.
Systems generally run $1,500 to $8,000, depending on the foundation, how many zones need to be covered and how hard the pipe is to route. Sometimes the answer is simpler and cheaper, such as sealing obvious openings and improving ventilation with an HRV, particularly on a borderline result.
When we mitigated our own house, we got three quotes:
We went with the $6,500 quote. Ten minutes on site isn’t long enough to work out where the pipe should go, and a system nobody tests afterwards might not be doing much.
What to Ask a Mitigation Contractor
- Are you C-NRPP certified?
- How long will you spend on site before quoting, and will you do diagnostic testing to find out how the gas moves under the slab?
- Where will the fan and pipe run, and how will it look and sound?
- Is a follow-up radon test included, and how long after start-up?
- What result are you targeting, and what happens if we don’t get there?
Local Radon Companies
Thrive doesn’t do radon testing or mitigation. Companies working in the Okanagan include Synergy Radon, Point the Way Radon Services and Radon Care. Health Canada’s C-NRPP directory lists certified measurement and mitigation professionals across the country.
Frequently Asked Questions (FAQ)
How much does a radon test cost?
A long-term kit is usually $40 to $80 including the lab fee, and some municipalities, regional districts and libraries hand them out free or lend digital monitors.
How long does a radon test take?
At least 91 days, with those days falling in the heating season. Anything shorter can’t be compared to the 200 Bq/m³ guideline.
My house is new. Do I still need to test?
Yes. Homes permitted since March 2024 have a radon rough-in, but a rough-in isn’t a working system, and new houses can still test high. Test after you move in and go through a heating season.
Does a basement suite or a crawlspace change anything?
Test the lowest level people actually use. If you have a suite downstairs, that’s where the people are, so that’s where the test goes.
Can air sealing make radon worse?
It can raise the concentration if radon is getting in and ventilation doesn’t keep up. Test before and after, and make sure the house has working ventilation.
Will an HRV fix a high radon level?
It can help, and on borderline results it’s sometimes enough. High results usually need soil depressurization, which removes the gas before it gets in rather than diluting it afterwards.
Do I have to tell a buyer about a high result?
Talk to your realtor or a lawyer about disclosure. A mitigated house with test results in hand is an easier sell than an untested one.
About The Author
