Buy a radon test kit
Place the kit in the lowest lived-in level of the home
Keep windows and exterior doors closed during the test period
Follow the kit instructions exactly
Leave the kit in place for the required time
Seal and mail the kit to the lab if required
Review the test result when it returns
Retest if the result is near or above the action level
Hire a certified radon professional for a long-term or confirmatory test
Use a continuous radon monitor for real-time measurement
Test again after major renovations, foundation work, or HVAC changes
Test each home or unit separately if needed