Radon decisions should begin with a measurement and a clear testing purpose. Tell the provider whether the test is for your own planning, a property transaction, or a follow-up after mitigation. Ask which locations, conditions, duration, and reporting method are appropriate to that purpose.
Understand the Result
EPA recommends fixing homes at 4 pCi/L or higher and considering mitigation between 2 and 4 pCi/L. EPA also states that no known safe exposure level exists; a result below the action level is not a guarantee of no risk. Ask the testing professional to explain uncertainty and any recommended confirmation.
Compare a Defined Mitigation System
A proposal should describe the planned approach for the actual foundation, routing, equipment placement, electrical work, discharge, and appearance. Ask how separate basement areas, crawlspaces, or additions affect the design. Clarify the post-installation test, documentation, maintenance, and what the contractor will do if the agreed performance target is not achieved.
- What qualifications and testing protocols will the provider use?
- Who performs the follow-up measurement, and when?
- What indicator or alarm shows whether the installed system is operating?
Measure the Home Rather Than Guessing by Region
A regional map or a neighbor's result cannot determine the radon level in your house. Discuss the foundation layout, occupied lower levels, recent alterations, and heating or cooling patterns with the testing provider. Follow the selected test's instructions, including any required closed-building conditions, rather than changing ventilation to influence the result. Ask your state radon program about provider requirements and available guidance. For mitigation, clarify how additions, multiple foundation areas, or later energy improvements affect the design. Keep the installation records and post-work test results, and discuss when another measurement is appropriate.
Questions Homeowners Ask
Can a neighbor’s result tell me mine?
No. Arrange a measurement for your home under the appropriate protocol. Nearby information can encourage testing but does not establish your indoor result.
Does a working fan prove the radon level is acceptable?
No. Equipment operation and measured indoor radon are different checks. Ask for the follow-up testing and ongoing review recommended for the installation.
Sources And Local Resources
Official sources checked October 17, 2026. Confirm current requirements with the authority responsible for your property.
- U.S. EPA: Radon Action LevelEPA recommends fixing at 4 pCi/L or above and considering action at 2–4 pCi/L; no known safe exposure level.
- U.S. EPA: Radon ResourcesTesting is needed to know a home’s radon level; links to state and tribal program guidance.