Buying an Alberta Home? Make a Radon Testing Plan

Add radon to your property questions early

When you are comparing homes in Calgary or Grande Prairie, ask whether the property has been tested for radon. Radon is an invisible, odourless radioactive gas that can enter buildings from the ground. Long-term exposure can increase lung-cancer risk. MyHealth Alberta notes that both new and older homes can have elevated levels, and neighbouring houses can have very different results.

That makes the individual property's testing history more useful than reassurance based on its age or neighbourhood. Put the question on your list before an offer deadline gets close.

Sources: MyHealth Alberta: radon

A home inspection and a radon test run on different timelines

Health Canada's current measurement guide recommends testing for three to twelve months, including at least 91 days during the heating season. The aim is to estimate the home's annual average. A brief reading during an inspection cannot establish that long-term result.

RECA notes that the offer and condition-removal process rarely leaves enough time for reliable radon testing. Ask your inspector exactly what any proposed radon service includes. If a suitable test has not already been completed, discuss the uncertainty, possible mitigation costs and your offer conditions with your real estate professional and lawyer.

Sources: Health Canada: Guide for radon measurements in homes; Real Estate Council of Alberta: radon information bulletin

Request the report and the work history

RECA's buyer checklist recommends obtaining test results and, where mitigation has been completed, evidence of the work and follow-up testing. Start a small radon file alongside your other property documents.

• Ask for the full test report, including dates, duration, device and room tested.
• Ask whether substantial renovations have taken place since the test.
• If a mitigation system is installed, request contractor details, receipts and subsequent results.
• Ask whether the home has a radon rough-in and have a qualified professional assess its usefulness. A rough-in alone does not establish the home's radon level.

Sources: Health Canada: Guide for radon measurements in homes; Real Estate Council of Alberta: residential buyer radon checklist

Read the long-term average in context

Canada's guideline is 200 becquerels per cubic metre, written as Bq/m³. Health Canada recommends corrective action within one year when the average annual level exceeds that guideline, with faster action at higher concentrations. A result below the guideline is not a promise of zero risk.

Compare the guideline with the long-term average rather than an hourly peak. If a test below 200 Bq/m³ included fewer than 91 heating-season days, Health Canada recommends retesting during the next heating season. For a result close to the guideline, ask a qualified radon professional about measurement uncertainty and next steps.

Sources: Health Canada: Guide for radon measurements in homes; Health Canada: radon guideline

Get a property-specific mitigation plan

Health Canada recommends using a mitigation professional certified through the Canadian National Radon Proficiency Program (C-NRPP). A common approach uses a pipe and fan to draw soil gas from beneath the foundation and discharge it outdoors. The appropriate design depends on the house.

Request a written assessment and quote rather than relying on a general repair allowance. Ask what installation, follow-up testing and ongoing system checks are included. Keep the completed work records for your own use and any future sale.

Sources: Real Estate Council of Alberta: residential buyer radon checklist; Health Canada: reducing radon levels in your home

Make the next step clear before and after the move

If you are selling, discuss existing results with your real estate professional before listing. RECA's seller checklist identifies an unmitigated result of 200 Bq/m³ or higher as a material latent defect requiring disclosure. Get advice about your property's records and obligations.

If testing remains on your move-in list, choose a suitable long-term kit or certified measurement professional, follow the placement instructions and calendar the test's end date. Plan for follow-up testing after mitigation or changes affecting the home's structure or ventilation.

Sources: Health Canada: Guide for radon measurements in homes; Real Estate Council of Alberta: residential seller radon checklist; Health Canada: testing your home for radon

Before you act

General educational information, not individualized health or legal advice. Confirm property-specific testing and mitigation with a qualified radon professional, and contract or disclosure questions with your lawyer and real estate professional.