How should I handle radon when buying or selling a Tennessee home?
Test during the sale. Tennessee requires sellers to disclose radon problems they know about, but no one is required to test, so a disclosure form that says "no" or "unknown" doesn't tell you the radon level (Tenn. Code Ann. § 66-5-201 et seq.). EPA recommends sellers test before listing and buyers test before closing if no recent result exists (EPA Home Buyer's and Seller's Guide to Radon).
Key facts
- Tennessee sellers must disclose known radon problems on the property disclosure form; testing isn't required (Tennessee radon laws).
- Some sales need no disclosure form at all, including the first sale of a new home with a written builder warranty (Tenn. Code Ann. § 66-5-209).
- Fix the home if the average of two short-term tests, or a continuous-monitor average, is 4 pCi/L or higher (EPA).
- Every new home should be tested after move-in, even if it was built radon-resistant (EPA).
What does a Tennessee seller have to disclose about radon?
Sellers of most homes with one to four units must give buyers a disclosure statement that covers known environmental hazards, including radon (Tennessee radon laws). It covers only what the seller knows. A seller who never tested has nothing to disclose, and buyers can waive disclosure. Several kinds of sales are exempt, including foreclosures, many transfers between family members, and sales by an owner who hasn't lived in the home in the previous three years (Tenn. Code Ann. § 66-5-209).
How do I test for radon during a home sale?
EPA lists three short-term options for real estate tests, each running at least 48 hours in the lowest level that could be used as living space (EPA):
| Option | How it works | Fix the home if |
|---|---|---|
| Two tests at once | Two identical short-term tests side by side | The average is 4 pCi/L or higher |
| Two tests back to back | One short-term test, then a second right after in the same spot | The average is 4 pCi/L or higher |
| Continuous monitor | An electronic monitor that records radon hourly | The average is 4 pCi/L or higher |
For a valid test:
- Keep windows and outside doors closed for at least 12 hours before and during a test that lasts under four days.
- Place the test at least 20 inches off the floor, away from drafts, heat, humidity and outside walls.
- Ask the seller or occupant to sign a non-interference agreement; many professionals also use tamper-evident seals or monitors that log movement.
EPA recommends a qualified tester for real estate tests (CDC). Tennessee doesn't license radon testers, so look for NRPP or NRSB certification. See how to find a certified radon professional.
What if the radon result comes back high?
High radon is fixable, and EPA notes most homes can be fixed for about the cost of other common repairs (EPA). Buyer and seller can negotiate who pays and when the work is done, and the contract can spell that out.
- Get estimates from one or more certified mitigation professionals.
- Sealing cracks alone isn't enough; EPA doesn't recommend sealing as the only fix.
- Retest after the system is installed, ideally with an independent tester rather than the company that installed it.
See how radon mitigation works and what your result means.
What should I ask about a newly built home?
Ask the builder whether radon-resistant features were installed and whether the home was tested. Whether those features are required depends on the city or county that issued the building permit; your county guide shows the local rule. Test after you move in either way. If the result is 4 pCi/L or higher and the home has a passive vent pipe, adding a fan can turn it into an active system (EPA).
What if the home already has a radon system?
Ask the seller for the system's paperwork and the most recent test result. Before testing, make sure the fan is running, and keep it running for the whole test. Ask whether the house has had structural or heating and cooling changes since the last test, since those can change radon levels (EPA).
Buyer checklist
- Ask the seller for any past radon test results and mitigation records
- Read the disclosure form's radon answer, and remember it covers only what the seller knows
- Add a radon test to your inspection period, using a certified tester
- If the result is 4 pCi/L or higher, negotiate the fix and who pays
- After closing, retest after any mitigation and every 2 years with a system
Frequently asked questions
Does Tennessee require a radon test to sell a house? No. Tennessee requires disclosure of known radon problems but doesn't require testing.
Can I use the free state kit during a home sale? The free kit is a 3–5 day do-it-yourself test. EPA recommends a qualified tester for real estate, and a certified professional's report is easier to rely on in a negotiation. The free kit is a good choice after you move in.
Should a seller fix radon before listing? EPA recommends testing before listing. Fixing early gives the seller more time and control, and a record of the fix and a follow-up test can be a selling point.
Next step: Find a certified radon tester →
Sources: EPA – Home Buyer's and Seller's Guide to Radon (PDF) · Tenn. Code Ann. § 66-5-210 · Tenn. Code Ann. § 66-5-209 · CDC – Testing for Radon · NRPP · NRSB
Last reviewed October 22, 2026 by the Tennessee Radon Authority editorial team. How we research.