Radon Precautions for Buyers and Sellers

Published on 30 July, 2020
older couple working with real estate professional

It is important for home buyers and sellers to understand the risks associated with radon levels in homes, and to have enough information about radon to make an informed decision when buying or selling real estate. 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 and reach dangerous levels. According to Health Canada, radon is the second leading cause of lung cancer in Canada after smoking. In 2014, the BC government amended the building code to require new properties to include rough-ins, or a passive pipe in the basement, which can make it easier (and cheaper) to install a radon mitigation device in the future if it’s needed, for radon remediation in certain areas. Radon is measured in becquerels per cubic metre (Bq/m3). This consumer guide answers some common questions about radon levels and property sales in BC. For more information about radon, visit the website of the BC Lung Association.

Radon Precautions for Buyers and Sellers

It is important for home buyers and sellers to understand the risks associated with
radon levels in homes.

  • How much radon is too much?

    Radon is measured in becquerels per cubic metre (Bq/m3). 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 a material latent defect and both you and any real estate professional you are working with have an obligation to disclose this to a potential buyer. 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 should 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. If you have not completed a radon test, a buyer may reduce their offer price, or request to holdback funds, so that the homecan be tested, and remediated if necessary, after the sale.

  • As a buyer, what should I be asking about radon?

    Ask if the seller has conducted a long-term radon test and if they have, request a copy of the results. If they have done a test, ask where in the home the test was done. If the main floor 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 no test was done or a test should be redone, you may want to request a holdback to use those funds for mitigation if testing shows high levels of radon. Talk to your real estate professional about your options for structuring your offer in these circumstances.

  • 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 as more people become aware of its risks, you may see more buyers 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 holdback funds, so that the home can be tested, and remediated if necessary, after the sale.
  • How is testing done?

    Health Canada recommends that only testing of at least 90 days be used because shorter term tests are not 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 requires you to put a small plastic “puck” in the lowest level of your home that is occupied for four or more hours daily. 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 days testing you can send the test in and get the results.

    You may 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. Visit their website to find a radon tester or mitigation expert in your area.

  • 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 unduly complicated. Remediation can be completed in a few days and at the time of this writing, rarely exceeds five thousand dollars. You should seek further advice from a radon remediation specialist regarding costs.
  • Is radon prevalent in condominiums or townhomes?

    Townhomes, much like single-family homes, are tested in the lowest occupied level of the home that is 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 may wish to consider 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 do I go for more information?

    Here are some links that may help:

    If you have questions about radon or any other aspects of a real estate transaction, our Professional Standards Advisors are here to help. Contact them by calling 604.683.9664 (toll free 1.877.663.9664) or by email at [email protected].