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Consumer Guide to Radon
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This FAQ explains what radon gas is and when high levels of the gas must be disclosed by your agent to a buyer. The information also explains how to test for radon, and where to get more information about the impacts of radon on your health.
What is radon?
Radon is a naturally occurring, radioactive, odourless and colourless gas that is generated through the decay of uranium and other elements in soil minerals. As radon seeps up through the ground, it can find its way into your home through cracks in your property foundation and walls. Because new homes are built to be energy efficient and are sealed from the outside, radon can build up in your home over time to dangerous levels.
According to Health Canada, radon is the number two cause of lung cancer in Canada behind smoking. In 2014, the BC government amended the building code to require new properties to include rough-ins for radon remediation.
Do I have to test my house before selling it?
No. There are currently no legal requirements to test your property for radon. That being said, radon is the number two leading cause of lung cancer in Canada after smoking, and as more people become aware of its risks, more buyers will be asking for radon test results when they make offers. If you have not completed a radon test, a buyer may reduce their offer price, or request to hold back funds, so that the home can be tested, and remediated if necessary, after the sale.
How is testing done?
Health Canada recommends that only long-term tests of at least 90 days be used. Shorter term tests are not nearly as accurate. Radon tests can be purchased at a hardware store, and from online radon detection and mitigation services. The test is simple to perform and just requires you to put a small plastic puck in a specified area of your home on the lowest occupied level for four or more hours a day in. For instance, if you only use your basement for laundry, you would not test that level but would test the next level up in your home. After 90 or more days you can send the test in and get the results.
Some people may also prefer to work with a professional to test for radon. In Canada, radon testing and remediation companies must be certified through the Canadian National Radon Proficiency Program (C-NRPP). To find a radon tester or mitigation expert in your area, you can visit the following website: https://c-nrpp.ca/find-a-professional/.
How much radon is too much?
While Health Canada suggests there is no safe amount of radon, anything over 200 Bq/m³ should be remediated within two years. Anything over 600 Bq/m³ should be remediated within a year.
Do I have to tell a buyer how much radon is in my home?
Radon levels above 200 Bq/m³ are considered to be a material latent defect and must be disclosed to a potential buyer by your real estate professional. Levels below 200 Bq/m³ do not need to be disclosed, however if a buyer asks about radon levels and whether your home has been tested, you must either provide a truthful answer or refuse to answer the question.
Having your home tested will put you in the best position to deal with potential radon in your home. You may decide to remediate before you list your home for sale which is a value added for any buyer, or you may choose price your home to reflect that buyers may need to remediate the property after the home transfers.
How difficult is it to remediate a radon problem and how much does it cost?
Unlike many structural issues that can arise in a home, radon remediation is not complicated. It can take a few days to complete and on average, in urban areas, and is not overly expensive.
As a buyer, what should I be asking a seller about radon?
- First, ask the seller if they have conducted a long-term radon test and if they have, request a copy of the results.
- Ask where in the home the test was done. If it was the main floor that was tested because the sellers never use the basement, but you plan on spending more than four hours down there, you may want it to be tested again If the results are above 200 Bq/m³, you may want to speak to your real estate professional about reducing your offer by the approximate cost of radon mitigation.
- If no test was done, you may want to request a holdback to use those funds for mitigation if testing shows high levels of radon.
Is radon prevalent in condominiums or townhomes?
Townhomes, much like single family homes, are tested in the lowest level of the home occupied for four or more hours a day. The differences are evident, however, in how the property is remediated. If your townhome sits over a large common garage, venting of radon may need to occur at that point instead of in your basement. Regardless of where remediation work needs to be done, if your townhome is part of a strata corporation, the strata council will need to approve and engage a radon mitigation expert.
If you are in a condominium tower, your strata corporation should be testing all levels of the building. As a unit owner, you can test your suite. If levels of radon exceed 200 Bq/m³, notify your strata council or strata management company so that they can discuss potential remediation.
In taller towers, radon will also typically affect those occupying spaces below grade or at ground level more than those who occupy space on upper levels. Sometimes, however, it is the upper units which experience higher levels of radon. This is known as the stack effect. Because warm air rises, it can draw air up through elevator shafts and stairwells allowing radon gas to accumulate on the higher floors.
Mitigation efforts such as venting parkade air and adjusting HVAC systems can often reduce the stack effect.
Where can I go for more information?
Here are some links that may help:
- Government of Canada Radon Guideline: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/radiation/radon/government-canada-radon-guideline.html
- Radon testing and mitigation specialists: https://c-nrpp.ca/find-a-professional/
This content was developed with financial support from the Real Estate Foundation of BC.