BC Building Code Radon Requirements: What 'Radon-Ready' Actually Means for Your Home
BC's building code requires radon vent rough-ins in new homes. Here's what 'radon-ready' actually means, what it doesn't do, and what every BC homeowner needs to know.
If you’ve purchased or built a new home in BC in recent years, you may have heard that it’s “radon-ready.” The phrase sounds reassuring — as though the problem has been handled. It hasn’t.
BC’s building code requires radon vent rough-ins in new residential construction across much of the province. BC Radon Control is C-NRPP certified for both radon testing and mitigation throughout the Fraser Valley. Understanding what this requirement actually covers — and what it leaves unaddressed — is something every BC homeowner should know.
What BC’s Building Code Actually Requires
BC’s building code requires new residential construction to include a radon vent rough-in. This is a pipe — typically a 4-inch PVC sleeve — installed through the concrete slab or beneath the sub-floor membrane, running from below the foundation up through the structure and out through the roof.
The rough-in creates the pathway for a future sub-slab depressurization system. It does not draw air. It does not create suction. It does not reduce radon levels in your home. In the plainest terms, it is an empty pipe that makes future mitigation faster and less disruptive if levels turn out to be elevated.
The requirement reflects a meaningful commitment in BC’s building code to make radon mitigation more accessible in new homes. It is not a statement that new homes are safe from radon.
What “Radon-Ready” Actually Means
A home described as “radon-ready” has the rough-in infrastructure in place. Installing an active sub-slab depressurization (ASD) system in a radon-ready home is faster and often lower-cost than in a home without one — because the pipe penetration through the slab has already been done.
What “radon-ready” does not mean:
- The home has been tested for radon
- Radon levels are below Health Canada’s action level of 200 Bq/m³
- A mitigation system has been installed or activated
- You are protected from radon exposure
A new home can have a radon rough-in and still have radon levels of 600, 800, or higher Bq/m³. The rough-in is preparation infrastructure. Without a test and — if needed — an active mitigation system, it provides no protection.
Why New Homes Can Still Have High Radon
Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil and rock. Its concentration beneath any given plot of land is determined by local geology — and geology does not respect construction vintage.
A home built in Chilliwack in 2024 sits on the same soil as a home built in 1985. If the soil has elevated uranium concentrations — and much of the Fraser Valley does — both homes can have elevated radon. The building code requirement ensures the new home has an easier path to mitigation if levels are elevated. It does not change what the soil below the slab contains.
Additionally, concrete slabs in new homes develop hairline cracks as they cure and settle. Floor drains, utility penetrations, and sump pits are all potential radon entry points regardless of construction year. A rough-in does not seal these pathways — it only provides the infrastructure to depressurize beneath the slab once an active fan is connected.
Existing Homes: The Larger Risk Pool
The building code requirement applies to new construction. The majority of homes in the Fraser Valley — particularly those built before the requirement came into effect — have no rough-in and no mitigation infrastructure in place.
For owners of older homes, the absence of a rough-in does not make mitigation impossible. A C-NRPP certified contractor performs sub-slab diagnostics, drills through the existing concrete slab at the optimal suction point, routes the pipe through the structure, and installs the fan. The work takes one day in most cases and the result is the same: radon drawn from beneath the foundation and vented safely above the roofline.
Health Canada recommends that all homes in Canada test for radon regardless of age. This is because no home characteristic — construction year, foundation type, or code compliance status — predicts radon levels reliably enough to substitute for a direct measurement.
What to Do if Your Home Has a Rough-In
If your home has a radon vent rough-in, here is the correct sequence:
1. Test first. The rough-in tells you nothing about your current radon levels. Test with a long-term alpha track detector (91 days minimum) — this gives you the most accurate picture of your home’s annual average. For real estate transactions, a short-term professional test (96-hour minimum) using a continuous monitor is the C-NRPP-accepted format.
2. Interpret your results using Health Canada’s guidelines. Below 100 Bq/m³: no action required, retest every few years. Between 100 and 200 Bq/m³: consider mitigation, particularly if there are children or smokers in the home. Above 200 Bq/m³: Health Canada recommends mitigation.
3. Activate the rough-in if mitigation is needed. A C-NRPP certified technologist connects a fan to the existing rough-in pipe, seals accessible entry points, and installs a pressure indicator. The system runs continuously and silently. This is the point at which “radon-ready” becomes actual radon protection.
What to Do if Your Home Doesn’t Have a Rough-In
For homes without a rough-in — the majority of the housing stock across the Fraser Valley — the process is the same, with one additional step at installation:
1. Test. Same protocol: long-term test for an accurate annual average, or short-term for a real estate transaction.
2. If elevated, have a full system installed. A C-NRPP certified contractor performs sub-slab pressure diagnostics to locate the optimal suction point, drills through the slab, routes and installs the pipe, and connects the fan. Foundation cracks and visible entry points are sealed as part of the installation.
BC Radon Control installs mitigation systems in one day. Our systems are guaranteed to bring radon levels below Health Canada’s 200 Bq/m³ action level — and typically achieve under 30 Bq/m³. Every installation includes a post-installation verification test, a 1-year labour warranty, and a 5-year manufacturer warranty on the fan. If levels don’t drop below 200 Bq/m³, we return at no charge.
For a full explanation of what mitigation involves and what to expect on the day of installation, see our radon mitigation page. For testing options — both long-term and short-term — see our radon testing page. If radon came up during a real estate transaction, our guide to radon and real estate in BC covers disclosure obligations, what test is accepted, and how to negotiate around elevated results.
The Bottom Line
BC’s building code radon requirement is meaningful progress. It ensures that new homes have the infrastructure to make mitigation faster and less disruptive when it’s needed. But it does not test homes, does not install active systems, and does not protect occupants on its own.
The only way to know your home’s radon level is to measure it. The only protection comes from knowing — and acting on what you find.
If you’re in the Fraser Valley and want certified radon testing or a mitigation quote for a new or existing home, BC Radon Control offers free quotes with no obligation. Contact us to get started.
Have questions about radon in your home?
Speak with a C-NRPP certified professional in the Fraser Valley.