Under Ontario’s new-home warranty program administered by Tarion, if a long-term radon test shows average indoor levels exceed the guideline of 200 Bq/m³, the warranty covers radon mitigation costs up to $50,000. carst.ca The claim requires a certified test (minimum three months) and mitigation must be performed by a certified professional. carst.ca

For homeowners of newly built properties (typically within the first 7 years) this coverage provides significant peace of mind. carst.ca

This video explains how the Tarion Warranty Corporation warranty covers excessive radon in new homes built in Ontario. It defines Radon, how it enters homes through the ground, and why testing is essential. The video outlines the steps: long-term measurement (ideally 91 days), what happens if levels exceed the guideline (200 Bq/m³), and how buyers should ensure both builder registration and radon mitigation are included in their warranty coverage. It emphasizes that early detection and proper mitigation protect both health and warranty rights.

Ontario New Home Warranty - Radon Coverage

Under Ontario’s Tarion Warranty Program, radon issues are covered when indoor levels exceed 200 Bq/m³, as per Health Canada guidelines. Claims may qualify under:

• Year 1 - Fit for habitation or Ontario Building Code (OBC) non-compliance
• Year 2 - Health and Safety (OBC violation)
• Years 3-7 - Major Structural Defect (MSD) coverage

Homeowners must submit C-NRPP-certified radon test results (minimum 3-month test).
Tarion’s financial limit for radon remediation is $15,000 per home.
Personal injury or property damage caused by radon is not covered.

(Source: Tarion / CARST Radon Warranty Guidelines)

Radon Testing: What Homeowners Should Know

Testing is the only way to know if radon is a concern in your home. Fall and winter are the best seasons to test because windows stay closed and radon levels tend to build. Tarion Even new homes should be tested - radon depends on the soil beneath the home, not just building age. Tarion If results exceed the Health Canada guideline of 200 Bq/m³, take action through mitigation. Tarion If levels are below that threshold, continue to monitor (e.g., every five years) because radon levels can change. Tarion

Eight Quick Facts About Radon

1. Radon is a naturally occurring radioactive gas formed by the breakdown of uranium in rock and soil. Tarion
2. Every home contains some radon because the gas can enter through cracks and openings in foundations. Tarion
3. High indoor radon levels over time increase the risk of lung cancer; it is the leading cause in non-smokers. Tarion
4. The guideline set by Health Canada is 200 Bq/m³; levels above this should be addressed promptly. Tarion
5. Since radon is invisible and odorless, the only way to know your level is to test. Tarion
6. The best time to test is during colder months when windows/doors are closed, typically fall/winter. Tarion
7. Elevated radon can be mitigated - certified professionals can install systems to reduce levels. Tarion
8. In Ontario, new homes under warranty: if a long-term test (at least 3 months) shows >200 Bq/m³, the new-home warranty covers remediation for up to around $50,000 (for purchase agreements signed after Feb 1 2021). Tarion

New Home Warranty: Radon Protection

In Ontario, your new-home warranty covers remediation if indoor radon levels exceed the guideline of 200 Bq/m³. Coverage lasts up to 7 years from possession of the home and may include up to $50,000 for mitigation work when the Purchase & Sale Agreement is signed after Feb 1 2021. A long-term test (minimum 3 months) must be performed by a device or professional certified under the Canadian National Radon Proficiency Program (C-NRPP).

If the builder fails to act on elevated radon levels, Tarion steps in.

As of February 1, 2021, the Home Construction Regulatory Authority (HCRA) became the official regulator for new-home builders and vendors in Ontario, overseeing licensing, competency and the Ontario Builder Directory. Tarion Meanwhile, Tarion focuses exclusively on administering new-home warranties and resolving disputes, rather than builder licensing. Tarion These changes strengthen consumer protection by separating builder regulation from warranty administration and providing clearer roles and accountability in the new-home market. news.ontario.ca