Asked & Answered: Key learnings on radon safety and testing
by Oana Hyatt
March 2026
The issue of radon gas in homes is a topic that we’ve received plenty of questions about over the years, particularly in terms of what the obligations of both the buyers’ and sellers’ agents are during the negotiating process.
Our new Claims Manager, Oana Hyatt, has summarized the most common questions and answers.
Question: What should I tell my buyers about whether radon testing is necessary before they buy?
Answer: Buyers’ agents should direct their clients to the BCFSA’s Consumer Guide to Radon which sets out that a radon level exceeding 200 BQ/m3 amounts to a material latent defect that must be disclosed by sellers. Buyers’ agents should also review the answers provided by the sellers in the Property Disclosure Statement, particularly question 3.V and 3.W, and may want to inquire further about when and where exactly testing was done in the home.
Radon levels are generally highest on the lowest floors of a home, and highest during the winter. If the sellers disclose that radon levels have been tested and have exceeded 200 BQ/m3, buyers’ agents should direct their buyers to resources regarding remediation measures, which may include obtaining a quote for those remediation measures and considering a purchase price adjustment.
If the sellers do not disclose any recent radon testing, buyers may want to consider including a holdback to be used for mitigation if testing shows high levels of radon. In drafting a holdback clause, consider that testing for radon may take at least 90 days and is best done during the heating season, when windows are likely closed.
Question: Do I have to worry about radon if I’m listing a property in the Lower Mainland?
Answer: Radon is found all over British Columbia, although the Interior region generally has a much higher proportion of homes showing radon levels exceeding the material latent defect threshold of 200 BQ/m3 than coastal regions.
In Oliver, BC, 57% of homes tested during the winter of 2024-2025 showed excessive radon levels. For the Lower Mainland, the BC Centre for Disease Control’s 2021 map estimates 3% of homes have radon levels exceeding 200 BQ/m3 and requiring remediation.
Note that radon levels can vary from house to house, due to factors including how the foundation was built, the type and source of certain construction material, and how much ventilation there is in the house. There is no area of the province that is radon-free and the BCCDC recommends people test everywhere.
Question: Do I have to worry about radon if I’m listing a newly-built or recently-renovated home?
Answer: It depends. For homes built with a building permit applied for on or after March 8, 2024, the BC Building Code requires at a minimum roughing-in of a subfloor depressurization system. Such a system does not guarantee a reduction in radon levels indoors, and the installation of a fan may be required to actively move contaminated air to the outdoors.
Buyers may wish to confirm that such a system was properly installed and inspected, and may wish to speak to a testing professional about its sufficiency and whether radon testing is still recommended.
For recently-renovated homes, testing is a good idea, especially if structural or building envelope changes were made such as installing new windows or insulation, or finishing a basement.
Question: Do I have to worry about radon if I’m helping buyers with purchasing a penthouse condo?
Answer: Possibly, due to the stack effect which is the natural movement of warm air upwards in cold climates.
For more resources, see:
- “Radon: What You Should Know about This Invisible Health Hazard” Oana Hyatt, Legally Speaking #577, October 7, 2024
- Radon Precautions for Buyers and Sellers, BCFSA’s Consumer Alert, July 30, 2020
- BCFSA’s Radon Precautions Guidelines, July 30, 2020
- It’s Radon Season, October 28, 2021
- “Homeowners Left on Their Own to Deal with Deadly Gas”, Gemma Boothroyd, The Tyee, January 9, 2026
- BCREA’s Radon for REALTORS course
