Radon is a naturally occurring radioactive gas that can enter homes through foundation openings, cracks in slabs, crawlspaces, and wall penetrations. Because it is odorless, tasteless, and invisible, the only reliable way to know whether radon is present at harmful levels is to test for it.
Including radon testing as part of your home inspection helps protect both your investment and your family’s long-term health.
What Radon Is and Why It Matters
Radon forms from the natural breakdown of uranium in soil and rock. Because it moves upward through the ground, it can seep into buildings and accumulate to elevated levels indoors.
According to the U.S. Environmental Protection Agency (EPA), exposure to elevated radon levels is the second leading cause of lung cancer in the United States and the leading cause among non-smokers:
https://www.epa.gov/radon
This makes radon testing an important consideration during a home inspection, especially in areas known for higher radon potential.
Radon Risk Is Not Limited by Geography
Radon levels vary significantly from home to home, even between neighboring properties. A home can test high for radon whether it’s new or old, small or large, finished or unfinished.
Because radon cannot be detected without testing, relying on geographic generalizations is not sufficient to assess risk.
How Radon Testing Works
Radon testing during a home inspection typically involves placing a radon monitor in the lowest livable area of the home for a specified period, often 48 hours or longer. These monitors measure the level of radon gas in the air and provide a concentration result in picocuries per liter (pCi/L).
The EPA recommends that homeowners take action to reduce radon levels if the result is 4.0 pCi/L or higher, but there is no known safe level of radon exposure:
https://www.epa.gov/radon/what-epas-action-level-radon-and-what-does-it-mean
Testing during the inspection process allows buyers to understand indoor air quality before closing.
Radon Testing and Negotiation
Knowing the radon level before closing gives buyers and sellers a clear basis for discussions. If elevated levels are found, options may include:
- Requesting mitigation system installation
- Asking for seller credits at closing
- Negotiating repair or price adjustments
Because mitigation systems can be installed both before and after purchase, having objective data helps buyers plan responsibly.
Radon Mitigation Is Effective
Radon mitigation systems — such as sub-slab depressurization systems — are proven to lower indoor radon concentrations when properly installed. The EPA provides guidance on the types of systems that can be used and what results can be expected:
https://www.epa.gov/radon/health-risk-radon
This information is useful for both buyers and homeowners planning long-term maintenance.
Make Radon Testing Part of Your Inspection
Home inspection radon testing isn’t mandatory, but it is a valuable addition, especially for health-conscious buyers. Because radon exposure risk cannot be assessed visually, a test is the only way to know whether a home has elevated levels.
Understanding radon levels early in the buying process allows buyers to address concerns proactively rather than reactively.
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