Predicted average indoor screening level below 2 pCi/L. EPA cautions that elevated homes occur in every zone. EPA map ↗
Franklin County Radon · Tennessee evidence brief
Franklin County, TN radon Zone 3 on the map. 7.0 pCi/L in the state’s test data.
Franklin County is labeled “low potential,” yet the state dashboard’s county average is above the EPA action level. Meanwhile, no local jurisdiction reviewed here requires radon-resistant new construction.
Radon in Franklin County, Tennessee: quick answers
EPA zone: Zone 3Region: Middle TennesseeState test data: State test figures couldn't be confirmed, so they aren't shown
Is radon a problem in Franklin County, Tennessee?
It can be. Franklin County is in EPA Zone 3, the lowest predicted radon-potential category (below 2 pCi/L on average). Homes with high radon are still found in Zone 3, and the Tennessee Radon Program has found homes needing action in every Tennessee county, so test to know your home's level.
Do new homes in Franklin County, TN have to be built radon-resistant?
No. Unincorporated Franklin County was listed as opted out of the state program, and Winchester, Monteagle and Decherd each adopted codes that leave out the radon appendix. Local code details
How do I test my home for radon in Franklin County?
Order a free short-term kit from the Tennessee Radon Program online or by calling 1-800-232-1139. Place it on the lowest lived-in floor, about 3 feet off the floor, for 3 to 5 days, then mail it back right away. How to test your home
What radon level means I should fix my home?
EPA recommends fixing your home if radon is 4 pCi/L or higher, and considering a fix between 2 and 4 pCi/L. Confirm a high short-term result with a second test first. What your result means
Who can test or fix radon in Franklin County?
Tennessee doesn't license radon professionals, so look for NRPP or NRSB certification. Search both national directories by ZIP code; certified professionals often serve Franklin County from nearby cities. How to choose a radon professional
01 / THE SIGNAL
The numbers demand context, not comfort.
The EPA map and Tennessee dashboard answer different questions. One predicts county-level potential; the other reports recent test results. Here they point in opposite directions.
2022–2023 tests; Franklin County label confirmed on two live loads. TN dashboard ↗
Shown in the Franklin County tooltip on the first verified load. Sample size is not available at the county level.
No NRPP- or NRSB-listed measurement professional was based in the county. Directory listings are not a census.
What the dashboard can support
The displayed county average is 7.0 pCi/L—above EPA’s 4.0 pCi/L action level—and the displayed median is 2.3. Those values were tied to the tooltip’s own “County: Franklin” label, reducing the map’s known mis-hover risk.
The pre- and post-mitigation charts cannot supply county percentages or counts: they show health-region aggregates, not Franklin County results.
02 / BUILDING CODES
No confirmed radon appendix anywhere reviewed.
Unincorporated Franklin County was listed as opting out of the state residential program. Each municipality with a published residential code omitted the edition’s radon appendix.
Unincorporated Franklin County
No IRC enforced through the state residential program
RRNC not requiredThe state’s May 2024 jurisdiction list, using data accurate as of December 23, 2023, marks the county OPT OUT. The status must be re-confirmed because opt-out resolutions expire after election cycles.
Winchester
2024 IRC · effective July 1, 2026
Appendix BE omittedThe city lists local sprinkler, electrical, footing, and smoke-alarm amendments, but no radon appendix. The 2024 adopting ordinance number is not published on the city page.
Monteagle
2018 IRC + Appendix Q only · Ord. #13-21, Aug. 2021
Appendix F omittedThe adoption names the tiny-house appendix only; the radon appendix is not included.
Decherd
2018 IRC · Ord. #435, July 2021
Appendix F omittedNo appendices are listed in the residential-code adoption.
Estill Springs
2018 IRC + Appendices J and Q; 2012 Appendix G · Ord. #22-465, Dec. 2022
Appendix F omittedThe adopted appendix list does not include radon.
Cowan
2006 IRC · Ord. #11-06-01, Aug. 2011
Appendix F omittedNo appendices are listed. The online codification was last updated in 2016, so a newer ordinance may not appear.
Huntland
No IRC · 1999 Standard Building Code · Ord. #2005-1, Mar. 2005
No radon provision foundThe published code predates the IRC. Its 2006 codification may not reflect later ordinances.
County-rule search: no Franklin County- or city-specific radon rule was found for public buildings, schools, or real-estate transactions. Tennessee’s statewide radon program offers free test kits and guidance; it does not turn these local code omissions into construction requirements. TDEC radon program ↗
How do I find a certified radon professional in Franklin County?
Tennessee doesn't license radon testers or mitigators, so national certification is the best way to check qualifications. The Tennessee Radon Program points residents to two directories: search them by ZIP code and widen the radius if nothing is listed nearby.
We don't recommend or rank companies. Before you hire, check the certification number in the directory yourself and ask for a follow-up test after any system is installed. Questions to ask a radon professional.
03 / FOR HOMEBUYERS
What the evidence changes at closing.
No local code or Zone 3 label proves a home is low-radon. The practical response is a measured result tied to the house.
Add a radon test contingency.
Tennessee’s disclosure form addresses known radon concerns, but the state does not require a seller to test. Ask for a test rather than relying on the absence of a prior disclosure. Disclosure form ↗
Test new construction too.
Winchester omits Appendix BE, the reviewed 2018-code towns omit Appendix F, and unincorporated status is listed as opt-out. “New” is not equivalent to “radon-resistant.”
Use the free-kit route.
TDEC offers free test kits statewide. With no locally based credentialed measurer in the directories, a homeowner kit is an immediate starting point. Request a kit ↗
Growth context: a 2026 estimate places Franklin County at 45,967 residents, up 7.29% from 2020. More homes and transactions do not change the science, but they enlarge the number of properties entering a market with no confirmed radon-resistant construction requirement. Population source ↗
04 / RADON TESTING RESOURCES
Radon testing resources
Practical ways to test, get live guidance, find a certified professional, and respond to a high result.
Test your home
- Free test kit from TDEC, Tennessee’s radon program.
- Buy a kit by phone: 1-800-SOS-RADON (1-800-767-7236).
- Live help with your questions: 1-800-55RADON (1-800-557-2366).
- Find a certified pro: NRPP 800-269-4174 · NRSB 866-329-3474.
Hotline information: U.S. EPA and CDC
If your result comes back high
1-800-644-6999 — the Fix-It Hotline, for general guidance on lowering radon in your home.
Hotline information: U.S. EPA and CDC
Learn more
Why it matters
- Radon causes about 21,000 U.S. lung cancer deaths a year — the second-leading cause overall and the number-one cause among people who never smoked.
- At 4 pCi/L, EPA estimates about 62 in 1,000 smokers could get lung cancer from lifetime exposure, versus about 7 in 1,000 people who never smoked.
- About 1 in 15 homes has high radon.
- Retest at least every 2 years if you have a mitigation system, and after renovations or changes to how you use the lowest floor. EPA recommends taking action at 4 pCi/L and considering it between 2 and 4 pCi/L.
Health statistics: American Lung Association
05 / SOURCE FILE
Primary evidence and supporting references.
Links below are grouped by the question they support. Live-directory and dashboard findings reflect checks performed October 15, 2026.
Radon risk and testing data
Residential codes
Professional directories and real estate
NRPP directoryhttps://nrpp.info/pro-search/
NRSB directoryhttps://nrsb.org/for-professional/
Population estimatehttps://worldpopulationreview.com/us-counties/tennessee/fastest-growing