Reduce radon in your home (factsheet)

If your radon test result is above the Canadian guideline of 200 Bq/m³, it's important to take steps to reduce it. This factsheet explains common ways to reduce radon in Canadian homes.

Radon mitigation options for existing homes

Reducing radon doesn't have to be complicated. Certified professionals trained through the Canadian National Radon Proficiency Program (C-NRPP) know how to tackle the problem. They'll find the most cost-effective solutions, using proven techniques to reduce your radon level.

Radon mitigation works. A system can usually be installed in less than a day and typically lowers radon levels by more than 90% at a cost similar to other common home improvements. For more information visit cnrpp.ca.

Active soil depressurization (ASD): Proven to work

Active soil depressurization is the most trusted and effective solution. This method can reduce radon levels by 90% or more, giving you peace of mind that your home is safe.

How it works:

• Install the system: A pipe installed through the foundation floor draws radon from beneath your home.
• Continuous protection: A fan attached to the pipe runs 24/7, pulling radon out and venting it safely outdoors.
• Tailored to your home: Certified specialists adjust the system for your home's design—whether you have a foundation slab, crawl space, or sump pit.

When installed by a certified professional, it works and performs reliably over the long term.

Balanced ventilation: Fresh air, lower radon

A balanced mechanical ventilation system can also help reduce radon levels by bringing in fresh air and removing stale air and radon gas. Examples include:

• Heat Recovery Ventilators (HRV)
• Energy Recovery Ventilators (ERV)

Ventilation systems are less effective than ASD. They need to be operated continuously, be well maintained and they generally reduce radon levels by only 20% to 50%.

Cracks, gaps around pipes and other potential radon entry points should be sealed to maximize the efficacy of a ventilation system.

Testing after installation: Make sure your system works

Step 1: Short-term test

Once your radon reduction system is turned on, it's important that a certified professionals perform a short-term radon test to confirm it is reducing the radon level to below the Canadian Guideline.

Step 2: Long-term test

During the first heating season after installation, do a long-term radon test in the same location as your original test. This will give you the most reliable picture of your home's reduced annual average radon level.

Step 3: Retest regularly

To ensure your system continues to protect you and your loved ones, inspect and maintain it regularly and retest for radon every five years.

Radon reduction in new construction

Building a new home?

When building a new home, you have the best opportunity to protect against radon from the start. Health Canada recommends that all new homes include a passive soil depressurization (PSD) system.

What is PSD?

PSD, also called a passive radon stack, is similar to an active soil depressurization (ASD) system but without a fan. A pipe runs from beneath the foundation to an exhaust point above the roof, allowing natural airflow to carry radon outdoors before it enters your home.

Why choose PSD?

Radon mitigation is more cost effective to install while the home is being built. PSD can reduce radon levels by 40-90% and can easily be upgraded to an ASD system by adding a fan if more reduction is needed.

Building radon protection into your new home is simple, effective, and gives you peace of mind for years to come.

Don't forget to test

If your new home has a passive radon stack, ASD system or HRV/ERV system, perform a long-term test (at least 91 days) during the heating season to ensure levels are below Canada's guideline of 200 Bq/m³.

Building radon protection into your new home is simple, effective, and gives you peace of mind for years to come.

For more information

For more information on radon testing and how to reduce radon in your home, visit: Canada.ca/radon.

For technical information refer to the Canadian General Standards Board document Radon mitigation options for existing buildings.