The highest potential category: predicted average indoor screening levels above 4 pCi/L. A zone is not a home test.
Loudon County radon • Tennessee
Loudon County, TN radon High potential. Uneven protection.
Loudon County is EPA Zone 1. New homes in the unincorporated county must be built radon-ready—but the rule changes at city and development boundaries.
Tellico Lake image: East TN Vacations
Radon in Loudon County, Tennessee: quick answers
EPA zone: Zone 1Region: East TennesseeState test data: State test figures couldn't be confirmed, so they aren't shown
Is radon a problem in Loudon County, Tennessee?
Yes, it can be. Loudon County is in EPA Zone 1, the highest radon-potential category, where the predicted average indoor screening level is above 4 pCi/L. Levels vary from house to house, so a test is the only way to know your home's level.
Do new homes in Loudon County, TN have to be built radon-resistant?
Yes in unincorporated Loudon County: its 2018 code, effective July 1, 2023, expressly includes the radon appendix. Whether Lenoir City and the City of Loudon adopted it couldn't be confirmed. Local code details
How do I test my home for radon in Loudon 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 Loudon 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 Loudon County from nearby cities. How to choose a radon professional
The county's 2018 IRC adoption makes passive radon-resistant new construction mandatory as of July 1, 2023.
NRPP and NRSB searches found no measurement professional based in Loudon County; the closest listings are in Knoxville and Oak Ridge.
01 / Building codes
The county line matters
Loudon County runs its own inspection program. But Lenoir City, the City of Loudon, and TRDA lands follow different code paths—and only one path is fully verified to include the radon appendix.
Unincorporated Loudon County
The county adopted the 2018 IRC for unincorporated areas and municipalities without their own equivalent code, effective July 1, 2023. Its appendix list expressly includes Appendix F, Radon Control Methods, with no amendment found that weakens it. Passive radon-resistant construction is therefore required for new dwellings covered by the county code.
“Appendix F Radon Control Methods; Appendix M Home Day Care – R-3 Occupancy.”
Read the county adoption resolution (PDF) · County Building Codes page
Lenoir City
The city says it enforces the 2021 IRC. The amendments are available only on request, so whether 2021 IRC Appendix AF—the radon appendix—is adopted could not be verified online.
City of Loudon
Ordinance 2025-16 adopted the 2021 IRC on final reading December 15, 2025. The amendment attachment is held by the recorder's office, leaving Appendix AF's status unverified online.
TRDA / Tellico Reservoir lands
The Tellico Reservoir Development Agency adopted the 2018 IRC with Appendices E, H, and J only. Appendix F is absent, so TRDA-governed properties—including much of the Tellico Village area—do not have an adopted radon-resistant construction requirement.
Important: radon-ready does not mean radon-tested
A passive system creates a pathway to vent soil gas. It does not prove the home's indoor level is low, and some systems need a fan added after testing. Test every new home—even where Appendix F applies.
02 / Risk & evidence
Zone 1, without a publishable county reading
The federal zone map points to elevated potential. Tennessee's dashboard can add context, but its Loudon County tooltip could not be verified well enough to publish a number.
EPA radon map
Highest potential category
1
Zone 3Zone 2Zone 1
EPA defines Zone 1 counties as having a predicted average indoor screening level above 4 pCi/L. The map predicts potential; only a test measures a specific home.
No Loudon County average, median, or maximum is reported here.
A confirmed Loudon tooltip could not be captured from the Tennessee dashboard. Repeated hovers landed on neighboring counties, demonstrating the mis-hover risk.
What the state dashboard can—and cannot—tell you
- Time window: the workbook displays 2022 and 2023 test years when the year filter is set to “All.”
- County map: tooltips may show an average, median, and maximum, but some values render blank.
- Not county counts: the pre- and post-mitigation bars are health-region aggregates. Loudon is folded into the East Region.
- Practical conclusion: the available dashboard does not support a Loudon-specific test count or percentage above 4 pCi/L.
No local radon rule was found for schools, public buildings, or sales
Searches found no Loudon County, Lenoir City, or City of Loudon ordinance comparable to Metro Nashville's public-building radon rule. Tennessee does not license radon professionals at the state level, and school testing is encouraged rather than mandated. Non-digitized local records could still exist.
How do I find a certified radon professional in Loudon 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 / Homebuyer guide
Verify the house, not the label
A Zone 1 map, a “radon-ready” claim, or an installed mitigation pipe is context—not a current measurement. Make testing and documentation part of due diligence.
For an existing home
- Write a radon contingency into the offer. Tennessee's disclosure form advises buyers to consider one; it does not require the seller to test or remediate.
- Use a certified professional. Tennessee does not license radon testers, so national NRPP or NRSB credentials are the meaningful check.
- Retest after mitigation. Verify that an installed system is operating and that a post-mitigation result exists.
Soil gas enters below the slab; a passive vent routes it above the roof.
For new construction, ask these questions
Which jurisdiction issues the permit?County, Lenoir City, City of Loudon, or TRDA can mean a different appendix status.
Was the radon appendix adopted?Ask for the adopted appendix list—not just the IRC edition.
Where is the vent termination?Confirm the passive system runs from below the slab or membrane to above the roof.
Is there a fan-ready electrical point?A passive system may need activation if the finished home tests high.
Was the finished home tested?Construction compliance alone does not establish the indoor radon level.
Can the builder provide the result?Keep the test report, system diagram, and any warranty with the home's records.
The unresolved questions worth closing
Lenoir City: request the 2021 IRC amendments from Codes Enforcement to confirm Appendix AF. City of Loudon: request Ordinance 2025-16's Attachment C from the recorder or building inspector. County: ask the clerk for the legible number of the 2023 code-adoption resolution. State dashboard: capture a tooltip that explicitly says “County: Loudon” before publishing any local average, median, or maximum.