What Are Testing Requirements: “Closed Building Conditions”?
If you’ve ever scheduled a radon test, you may have been told that your home or building must be under “closed building conditions.” But what does that really mean, and why is it so important? Closed building conditions ensure that radon test results are accurate and reflect the actual risk to occupants.
What Are Closed Building Conditions?
Closed building conditions are a set of requirements designed to keep indoor environments stable during a radon test. Specifically, they mean:
These conditions must be maintained for at least 12 hours before the test begins and remain in place for the entire testing period.
It is OK for normal Entry & Exit
Occupants and workers may come and go as needed, provided closed-building conditions are maintained and smoking is strictly prohibited.
Units must be move-in Ready.
Units must mimic exact conditions to those that wiull be in place durig normal occupancy. Door seals, drywall completed, flooring, appliances, etc must all be in place for accurate testing.
Why Closed Conditions Are Necessary
Radon levels inside a building fluctuate with weather, ventilation, and air pressure. Leaving windows or doors open can artificially lower radon concentrations, giving a false sense of safety. Closed building conditions create a “worst-case” scenario—trapping radon indoors so the test measures the highest likely exposure level.
How Long Conditions Must Be Maintained
👉 Bottom line: Radon testing under closed building conditions provides the most reliable results. Call The Radon Boss today to schedule your test with certified professionals—trusted nationwide for accurate testing and proven solutions.
