Radon is the one item on this list that will not show up on a home inspection, cannot be seen or smelled, and cannot be made a condition of your purchase. It is also, by some distance, the one with the most serious consequences.
And New Brunswick has a lot of it.
The number that matters here
1 in 4 New Brunswick homes have radon levels higher than the recommended 200 Becquerels per cubic meter (Bq/m3).
Government of New Brunswick — Office of the Chief Medical Officer of Health
One in four. That is the province’s own figure, and it is the single most important thing on this page.
The province is also clear that levels vary considerably from one area to the next, and that testing is the only way to know. There is no map that will tell you, no rule of thumb about which side of the river you are on, and no way to reason it out from the age or style of the house. Two houses beside each other can read very differently.
Why it is worth caring about
Health Canada is blunt about the risk:
Radon exposure is the number one cause of lung cancer in non-smokers … 16% of lung cancers are estimated to be from radon exposure, resulting more than 3,000 lung cancer deaths in Canada each year.
Health Canada — Radon: what you need to know
People who smoke and are also exposed to radon carry a higher risk again. And Health Canada notes that while the risk below the guideline is small, “there is no level that is considered risk free”.
I am not raising this to alarm anybody. I am raising it because it is cheap to test, usually inexpensive to fix, and almost nobody in a real estate transaction mentions it.
How it gets in
Radon comes up out of the ground and enters through the same openings that let water in — which is why this page and the one on wet basements are really two halves of the same conversation.
Health Canada lists the routes: cracks in foundation walls and floor slabs, construction joints, openings around water connections and support poles, floor drains and sumps, empty spaces in walls, and the water supply. Levels are highest in basements and crawl spaces, being closest to the source and the least ventilated.
If you are finishing a basement, or having exterior drainage done, that is the moment to deal with radon as well. The work overlaps almost entirely.
⚠️ Why this cannot be a condition of your offer
This is the part that catches people, and it is worth understanding before you write an offer rather than after.
A valid radon measurement takes at least 90 days, and ideally three to twelve months, and it should be done in the fall and winter when the house is closed up. Health Canada is explicit that short-term tests do not replace long-term testing.
No conditional period runs for three months. So radon is structurally impossible to test for before closing, and any short-term reading somebody waves at you during a transaction is not a substitute for the real thing.
What that means in practice: buy the house, test it in your first winter, and budget for mitigation in case. That is the honest sequence, and it is the same advice regardless of which house you buy, because one in four is not a risk you can dodge by choosing a different address.
What testing actually involves
A long-term alpha track detector is a small plastic device you put in the lowest lived-in level of the house, leave alone for three months or more, and post to a lab. It is not complicated and it does not need anybody to visit.
In New Brunswick, kits are available from NB Lung and from some hardware stores, or you can have a professional do the measurement for a fee. Put it in the room you actually use at the lowest level — a finished basement family room, not an unheated crawl space you never enter.
What it costs to fix
The province publishes the figure directly:
For most houses, a radon mitigation system typically costs between $3,000 and $5,000, though some may be higher.
Government of New Brunswick — Office of the Chief Medical Officer of Health
Set against the other things on an older Fredericton house — exterior foundation drainage at $10,000 to $20,000, or a full rewire — that is a modest number for the risk it removes. New Brunswick also points to the Homeowner Repair Program and the Lungs Matter grant programme as possible sources of support.
If your reading is over the guideline, Health Canada recommends corrective action within one year, and sooner the higher the level.
What I tell buyers and sellers
Buying: assume you will test. Put a kit in during your first fall, and hold the mitigation figure in the back of your mind as a possible year-one cost, the same way you would with a roof that has a few years left.
Selling: if you have tested and the result was low, that is a genuine and unusual selling point and I would say so in the listing. If you tested high and mitigated, that is also a selling point — a documented system and a follow-up reading is a better story than an untested house. Keep the paperwork.
What I would not do is test during a listing and then not disclose an unfavourable result. Once you know, you know.
Where to go from here
Radon overlaps with the other things worth checking in an older house here — wet basements most of all, since the entry routes are the same. Aluminum wiring, oil tanks and insurance and fogged windows are the others I check for. If you are buying outside the city on a well and septic, the rural and acreage guide covers water testing alongside this.
The buying guide covers what the rest of the purchase costs here. Or call or text me at (506) 261-7373. I answer my own phone.
Sources
- Government of New Brunswick, Office of the Chief Medical Officer of Health — Radon
- Health Canada — Government of Canada radon guideline
- Health Canada — Radon: what you need to know
This page is general information from a REALTOR®, not medical or health advice. Radon measurement and mitigation should be carried out using certified devices and qualified professionals. For health questions, speak with your doctor or the Office of the Chief Medical Officer of Health.
