The bottom line
High-potential geology. No radon-ready guarantee.
Athens, Etowah, and Sweetwater use the 2018 IRC, but none has a verified, enforceable radon appendix for homes. Unincorporated McMinn County has no residential building-code program. In a Zone 1 county, “built to code” and “new” do not mean radon-protected.
Zone 1 risk, with a small measured sample
McMinn County is in the EPA’s highest-potential category. The Tennessee dashboard’s McMinn-labeled tooltip returned identical values on two loads, but those voluntary reports do not describe every home.
>4 pCi/L predicted average
The zone designation is a broad planning signal, not a house result. Individual homes can test above or below the county prediction.
No jurisdiction requires radon-resistant construction
The county and its principal municipalities reach the same practical outcome through different code paths: no mandatory radon-control features for new one- and two-family homes.
Unincorporated McMinn
The county is not on Tennessee’s residential-permit-required county list. Its site offers electrical, septic, and flood-plain information, but no county building-permit program.
The opt-out resolution number was not located and remains an open record question.McMinn County official site ↗Athens
Ord. No. 1105, §8, passed December 21, 2021, adopts the 2018 IRC without naming appendices. The modifications address sprinklers, electrical, seismic, and energy provisions—not radon.
Under IRC R102.5, an appendix applies only when specifically adopted. Appendix F was not.Athens §12-267 ↗Etowah
Ord. 891, dated July 24, 2023, says “2018 IRC with appendices” without listing them. Etowah appears on the state permit-required city list, so the State Fire Marshal enforces the 2018 IRC for homes—and the state does not enforce optional appendices.
Whether Etowah’s own inspector applies Appendix F to any locally permitted work is not yet confirmed.Etowah §150.25 ↗Sweetwater
Ord. #998, adopted June 2022, replaced the city’s residential code with the 2018 IRC. Its exceptions address sprinklers, electrical, seismic, and energy provisions; no appendix list or radon provision appears.
Sweetwater is not on the state permit-required city list and enforces its own code.Sweetwater Municipal Code ↗Test every home, including a newly built one. None of these code paths guarantees a passive radon system, fan wiring, or post-construction radon measurement.
How do I find a certified radon professional in McMinn 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.
Ask for the test the paperwork will not prompt
Tennessee’s standard property-condition disclosure form has no radon-specific question. Buyers should make radon testing an explicit part of the inspection period.
Keep a radon contingency
Use the inspection window for a house-specific result. Disclosure is not a measurement.
Test new construction
Code minimums do not include the radon appendix anywhere in McMinn County.
Verify “radon-ready”
Request plans and component details rather than relying on a marketing label.
Plan for access
With no listed local pro, schedule early enough for an out-of-area tester during a short contingency.
U.S. Census QuickFacts reports 57,404 residents, 24,424 housing units, 75.8% owner occupancy, a $211,800 median owner-occupied value, and 125 building permits in 2025. More new homes and transactions are entering a Zone 1 county without mandatory radon-resistant features. Census QuickFacts ↗
Primary records and live directories
Code, dashboard, and directory checks were reviewed on October 16, 2026.
- MTAS statewide building standards
- Tennessee residential permits
- State permit jurisdiction lists
- Athens Municipal Code §12-267
- Athens Municipal Code §12-268
- Etowah Code §150.25
- Sweetwater Municipal Code
- McMinn County official site
- Tennessee Radon Testing dashboard
- NRPP professional search
- NRSB professional directory
- EPA Map of Radon Zones: Tennessee
- Census QuickFacts — McMinn County
The dashboard’s pre/post bar charts are Southeast Region aggregates, not McMinn County counts, and are intentionally not reproduced here. Illustration created for this guide to explain how soil gas can enter a home; it is not a photograph of a specific property.