Does radon lower a property’s value?

Published on May 29, 2026

The presence of radon in a house can affect a real estate transaction, particularly during a home inspection, a negotiation, or when obtaining a mortgage. In some cases, it may even be considered a hidden defect. Here’s what you need to know to better protect yourself when buying or selling.

Is radon in a home considered a hidden defect?

Yes. Radon in a residence can be considered a hidden defect if it was not disclosed, unless the sale is made without legal warranty.

The seller is not always required to provide a radon test. However, they must generally disclose any known results or work performed (with supporting invoices) to ensure transparency at the time of sale.

Good to know

A prudent and diligent person should always conduct a pre-purchase inspection. You may also, at your own expense, request a radon test before purchasing a home.

Positive radon test during a sale: What are your options?

If a test reveals elevated radon levels during a real estate transaction (above 200Bq/m³), you can renegotiate the purchase price or have radon mitigation work completed before the sale.

Pro tip

“Don’t have time for a radon test before a real estate transaction? You can include an escrow account in the sale agreement. The seller deposits an amount that can be used, if needed, to cover the cost of mitigation work within an agreed-upon timeframe. If radon levels in your home prove to be non-concerning, the amount is returned to the seller.”

Yves AllardAssistant Director, Residential, CAA-Quebec

Is it safe to buy a home with radon?

Yes, you can buy a home with radon if mitigation measures are planned or feasible.

Keep in mind that this radioactive gas can be present in any home in Quebec, regardless of its age or location. In Canada, approximately one in five homes has a concerning radon level, according to Health Canada, which can increase the risk of lung cancer.

Radon can also affect a property’s value. In some cases, its presence can become a negotiating factor. You may be able to have the sale price adjusted, especially if mitigation work is needed to reduce radon levels.

How to protect yourself from radon in a real estate transaction

When selling a home, be transparent. When buying, be vigilant if:

the building is located in a high-risk area; or
the basement includes a bedroom, home office, or family room where at least one person spends at least 4 hours a day.

You can make a conditional offer to purchase subject to a radon test. Of course, the seller must allow you to carry out the test. Be cautious if they refuse.

Good to know

In general, the radon test is paid for by the buyer when requested as part of a pre-purchase inspection. However, certain agreements between the parties may provide for cost-sharing or the seller covering the cost.

Is a home with a radon mitigation system an advantage?

A home equipped with a radon mitigation system can be viewed positively by potential buyers, as it indicates the radon problem has been addressed. However, it is important that the system is functional and that results are documented. This type of system is recommended by Health Canada and is the standard measure for radon remediation.

Can radon affect your home insurance premium?

No. Home insurance covers sudden and accidental events, not situations related to maintenance or gradual exposure. Since radon is generally not covered, it typically has no impact on your premium.

Where to find reliable information on radon in Quebec and Canada

You can find reliable information on radon from the following resources:

FAQ – Radon and real estate transactions

1. Can radon lower a home’s value?

Yes, the presence of radon can affect a property’s value and become a negotiating factor, especially if mitigation work is required.

2. Who pays for the radon test in a real estate transaction?

The test is generally paid for by the buyer as part of a pre-purchase inspection, but the parties may agree to a different arrangement.

3. What should you do if a radon test comes back positive during a sale?

Options include renegotiating the purchase price, completing the work before the sale, or setting up an escrow amount.

4. Is the seller required to provide a radon test?

No, but they must generally disclose any known results or radon-related work already completed.

5. Can your financial institution require a radon test?

Yes. While not common, a financial institution may require a radon test before approving a mortgage. This can happen, for example, if an inspection report raises concerns, if a previous test revealed high levels of radon, or if the property is located in a region with higher radon concentrations.