Radon Testing Before Buying a Home

Why Buyers Should Always Test

Radon levels vary significantly from house to house, even on the same street. A neighbor's clean test tells you nothing about the home you are buying. Sellers are not required by federal law to test for radon before listing or to disclose prior test results in most states. That said, many state disclosure laws require disclosure of known hazards. Ordering a radon test as part of the home inspection process takes the guesswork out of the equation and gives you documented, current results.

Short-Term Testing in Real Estate

Real estate radon tests are almost always short-term tests (48 hours to 7 days) because of transaction timelines. Tests should be placed in the lowest livable level of the home under closed-house conditions. The test should be performed by a certified tester, not collected by the buyer or the seller. This ensures the results are credible and conducted according to protocol. Electronic continuous monitors are common in real estate because they provide time-stamped data that demonstrates testing conditions were maintained throughout the test period.

What to Do If Results Are Elevated

If the test result is at or above 4 pCi/L, you have several options. You can request that the seller install a mitigation system before closing.

Sellers often prefer this to a price reduction, because a properly installed system resolves the issue permanently. You can negotiate a credit to cover the cost of mitigation after closing. You can order a confirmatory test to verify the initial result.

You can walk away from the transaction if results are extremely high and the seller is unwilling to remediate. Mitigation systems typically cost $800–$2,500 installed and reliably resolve the issue.

Reviewing Seller-Provided Test Results

Sellers sometimes provide prior radon test results as part of disclosure. When reviewing prior test results, check a few things. First, how old is the test. Results more than two years old may not reflect current conditions. Second, what type of test was used, since long-term tests are more reliable than short-term.

Third, was the test conducted by a certified tester or independently, since seller-conducted tests are less reliable. Finally, have there been renovation or construction changes since the test that could affect radon entry. When in doubt, request a new test as part of the transaction.

Radon and Real Estate Disclosures

Federal law does not require sellers to test for radon or disclose prior results, but many states have enacted radon disclosure requirements that apply to residential transactions. Sellers who are aware of prior test results showing elevated radon may have an obligation to disclose under state law and general common-law disclosure requirements. Buyers should confirm the radon disclosure requirements applicable in the state where the property is located. In all cases, independent testing is the most reliable protection.