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Asset Classes

Focus Area

Indoor Air Quality and Hazards


IAQ Hazards

Question #

I6.3 – Radon Risk Assessment


Has a Radon Risk Assessment been performed?


Applicable to all buildings (systems or equipment in the owner or landlord’s control)


Yes or No

If no, for properties located in Canada, go to link, find the region where this building is located and enter the % of homes in that region with high radon levels: ____ %


Radon is a colourless, odourless, naturally occurring radioactive gas present in soil, rock and water.

In outdoor environments the concentration of radon is low, and the associated health risk is negligible. However, radon can enter buildings through any openings that are in contact with the sub-surface soil and rock, and can accumulate to higher concentrations which results in a higher health risk for the occupants within.

Health Canada has identified elevated radon concentrations in every public health unit across Canada and as such, it is recommended that every building be tested in order to confirm if radon levels within are acceptable. The only way to know the radon concentrations that are present within a building is to test for it.


    1. Conduct testing in the following locations:
      • Radon testing must occur in all occupied areas where the floors or walls are in direct contact with the ground or is over crawlspaces, utility tunnels or parking garages. Health Canada defines an occupied area as one that is occupied by an individual for four hours per day
      • Unoccupied rooms should also be tested at the same time as occupied rooms if there are plans for them to become occupied in the near future
      • If none of the ground contact floors are occupied, test all occupied rooms on the first occupied floor level above
    2. Measurement of occupied areas within a building is required for a minimum duration of 91 days. The testing period will occur entirely during the heating season.
    3. Use only measurement devices approved by C-NRPP
    4. Final analysis must be completed by a laboratory certified by the C-NRPP or similar. Not all measurement protocols require laboratory analyses (e.g., E-PERM Electrets) so long as the analyst is accredited to conduct that analysis through C-NRPP
    5. The radon risk assessment report must be signed by an individual certified by the C-NRPP or similar certification body


    • Radon Risk Assessment Report

Adapted BB3 Question

Question 05.02.01 – Has a radon risk assessment been completed for the building?

Suggested Lead

In-house, with third-party support




Other Notes

High radon levels can potentially exist on upper floors due to the upward movement of air from stack effect or if radon is suspected to be emanating from building materials. However, Health Canada has conducted large-scale testing of federal buildings and these factors are not considered to be significant. If elevated radon levels are identified on the lower floors, the C-NRPP mitigation professional could potentially conduct diagnostic testing on the upper floors while the mitigation strategy is being developed, to confirm the full scope of mitigation required


3 Points