Schools
Tennessee encourages school radon testing; it does not require it, set a retest schedule or require radon-resistant new-school construction. No radon item appeared in the Union County school policy manual’s table of contents.1314
The safety gap starts before a home is occupied.
The State Fire Marshal’s 2018 residential code adopts only Appendix Q—not Appendix F for radon control. Union County, Maynardville and Luttrell are also absent from the state’s current residential-permit list. Maynardville’s own code names its adopted appendices and excludes radon.123
Zone 1EPA’s highest-potential county designation.4
154Building permits reported for 2025 amid continued growth.10
01 / BUILDING CODES
Radon-resistant construction is not required by the records found.
The enforcement path changes at jurisdiction lines, but no reviewed record supplies a radon-construction mandate.
Jurisdiction
IRC edition
Radon appendix
What the record supports
State residential program2018 IRCAppendix Q onlyRule 0780-02-23 adopts the 2018 IRC and Appendix Q. Appendix F—Radon Control Methods—is not adopted, and optional standards are excluded.1
Maynardville2018-based*Appendix F excludedOrdinance #O-2022-8, September 2022, uses 2018-code amendments and lists A, B, C, E, H, Home Day Care, P, Q and T; all others are excluded. *Codified §12-201 still says 2012, likely a lag that is not confirmed.3
LuttrellNot verifiedOpenNo municipal adoption was found online. Luttrell is absent from the current state-permit list, so its exact local-enforcement or opt-out status requires direct confirmation.2
Maynardville’s appendix list is unusually clear: the ordinance says all unlisted appendices are excluded, and Appendix F is not named. A builder can still install a passive system voluntarily.
Nearby contrast: Knox County adopted Appendix F with local amendments, so a new home just south may receive a passive radon rough-in while one in Union County is not confirmed to.5
02 / RISK & DATA
The zone designation is clear. The county numbers are not.
EPA classifies Union County as Zone 1. The Tennessee dashboard produced contradictory tooltip values, so they are shown only as an audit trail—not as county statistics.
EPA radon zone
1
The highest-potential category: predicted average indoor radon may exceed 4 pCi/L. It is a county-scale planning signal, not a result for an address.4
Why no average is published here
On one county-labeled load, the Tennessee dashboard showed average 3.4, median 1.6 and maximum 2.4 pCi/L—an impossible ordering because the average exceeded the maximum. After reload, the average was blank while median 1.6 and maximum 2.4 remained.
3.4 / blankAverage across two loads
1.6Median shown on both
2.4Maximum shown on both
All three values are withheld as suspect. The dashboard’s lower band charts aggregate by health region and did not become county-level when Union County was selected.6
03 / LOCAL RULES
No Union County-specific radon rule was found.
The review found no extra local requirement for public buildings, schools or home sales. That is an online-source finding, not proof that no unpublished policy exists.
Home sales
No county-specific testing rule was found. Statewide disclosure covers known hazards, including radon, but no test is required before a transaction. Buyers should put testing in the inspection period.15
Homeowner access
TDEC offers free radon test kits to Tennessee homeowners. For a time-sensitive purchase, consider a credentialed professional and verify the current listing.9
How do I find a certified radon professional in Union 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.
04 / BUYER GUIDE
New, lakefront or rural: make the test explicit.
Union County’s growth and Norris Lake market add new homes and second homes without a confirmed radon-code backstop.
01
Test during the inspection period
A known-hazard disclosure is not a measurement. Put radon testing in writing and leave enough time to receive and act on the result.
02
Ask what “radon-ready” means
For new construction, request photos and details of any sub-slab layer, gas-permeable material, vent route, sealing and fan-ready provisions. Then test after occupancy.
03
Verify the professional
No credentialed measurer was listed as based in the county. Check the current NRPP or NRSB directory before hiring a provider traveling from outside Union County.
Growth context: Census QuickFacts estimated 21,450 residents on July 1, 2025—up 8.3% from 2020—with 10,255 housing units, 80.2% owner occupancy, a $204,000 median owner-occupied value and 154 building permits in 2025.10
A Tennessee county profile reports a $280,000 median home sales price for 2023, while Maynardville’s FY2025 audit attributes higher permit revenue to “significant housing development activity.”1116
05 / FAQ
Union County radon questions, answered.
Short answers grounded in the October 16, 2026 code, zone, dashboard and directory review.
Is Union County in a high radon zone?
Yes. EPA designates Union County as Zone 1, its highest-potential category. A zone is not a property test, so homes can measure above or below the county-scale prediction.
Does Maynardville require radon-resistant new construction?
No. Its 2022 ordinance gives an explicit residential appendix list and excludes all others. Appendix F, Radon Control Methods, is not included.
What about Luttrell and unincorporated Union County?
Neither appears on the current State Fire Marshal list of places requiring state residential permits. Their exact local-enforcement or opt-out status could not be verified online, and no radon mandate was found.
What do the state dashboard numbers say?
The tooltip produced internally inconsistent values across two loads, including an average greater than the maximum. This page therefore publishes no Union County average, median or maximum from that dashboard.
How many certified testers are based in Union County?
Zero NRPP- or NRSB-listed measurement professionals were based in the county when checked October 16, 2026. Nearby providers were concentrated around Knoxville and Powell.
06 / SOURCES
Read the record.
Official sources establish the code and risk framework. Dashboard and directory findings are dated observations.
- Tennessee Rule 0780-02-23 — 2018 IRC and Appendix Q.
- SFMO state residential permit list.
- Maynardville Municipal Code, Title 12.
- EPA radon-zones JSON and map guide.
- Knox County 2018 IRC amendments.
- Tennessee Radon Testing dashboard.
- NRPP professional search near 37807.
- NRSB Find a Professional.
- TDEC free radon test kit request.
- Census QuickFacts: Union County.
- Tennessee county profile: Union County.
- Union County assessor building-permit fee, SB1918.
- 50-state school radon law review.
- Union County Board of Education policy manual.
- Tenn. Code Ann. § 66-5-210 (disclosure form) — secondary source; verify against the current transaction form.
- Maynardville FY2025 audit.
- Norris Lake / Maynardville image source.