The highest predicted radon-potential category. A zone still cannot determine one home’s reading.
Both local 2018 IRC records leave out Appendix F, Radon Control Methods.
No Greene County professional appeared in NRPP or NRSB searches on October 16, 2026.
01 / Risk & evidence
The zone is clear. The county readings are not.
Two independent references place Greene County in EPA Zone 1, associated with predicted indoor averages above 4 pCi/L. That planning label establishes elevated potential—not a reading for any individual house.67
Tennessee Radon Testing dashboard · 2022–2023
No defensible Greene County reading could be extracted.
The county tooltip was not exposed in the dashboard’s accessibility text, and repeated interactions did not produce a county-labeled result that could be verified. Average, median, maximum and county test count therefore stay unpublished.8
—County average not verified
—County median not verified
—County maximum not verified
Do not turn a region into a county
The pre- and post-mitigation charts were visibly labeled by health region, and Greene County belongs to the Northeast Region aggregate. The dashboard says clicking a county can filter those views, but that interaction could not be confirmed.
02 / Building codes
Two local enforcers. The same radon gap.
Greeneville and Greene County each operate their own code program. Both point to the 2018 IRC, but neither record adopts Appendix F—the chapter that contains Radon Control Methods.
Municipal enforcement
Town of Greeneville
Town Building Department
2018 IRC
Final ordinance number and effective date unverified
The available adoption document includes Appendices A, B, C, E, G, H, J, K, M, N, O, P and Q. Appendix F is absent, so radon-resistant new construction is optional under that record.13
County enforcement
Unincorporated Greene County
County Building & Zoning Office
2018 IRC + J
Resolution number and effective date unverified
The county says it adopted the 2018 IRC “with Appendix J.” Appendix J covers existing buildings and structures—not radon. Appendix F was not adopted.4
“Greene County has adopted the 2018 Edition of the International Building Code and the 2018 Edition of the International Residential Code with Appendix J.”
Greene County Building Safety/Codes page · read October 16, 2026
What Appendix F would add
The 2018 IRC identifies Appendix F as “Radon Control Methods,” with requirements intended to reduce soil-gas entry into a dwelling. Neither local adoption record includes it.3
03 / Local rules
No separate local radon rule was found
Research found no Greene County or Greeneville mandate for public buildings, schools or real-estate transactions beyond Tennessee’s statewide norms. That is a “not found” result, not proof that no internal practice exists.
Schools
Tennessee is classified as encouraging—not requiring—radon testing in public schools. No mandated retesting cycle or radon-resistant new-school requirement was identified.12
Public buildings
No local rule comparable to Metro Nashville’s public-building radon regulation could be located. A call to the county health department or Town Recorder would be needed to close the question definitively.
Real estate
Tennessee’s standard seller form explicitly names radon gas as a potential environmental hazard and advises buyers to consider a radon inspection contingency.11
How do I find a certified radon professional in Greene 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 / Homebuyer guide
New does not mean radon-ready.
The decisive local fact is the combination: Zone 1 potential, no adopted radon appendix in either jurisdiction, and no verified county dashboard reading to use as a shortcut.
Put testing in the contract
Tennessee’s standard disclosure names radon and advises buyers to include radon among inspection contingencies. “Unknown” is not the same as “tested.”11
Test new construction too
Neither Greeneville’s nor Greene County’s cited 2018 adoption includes Appendix F. Ask for any radon-system plans, but do not assume they were required.
Check current credentials
Search the NRPP and NRSB directories immediately before hiring. Listings, credentials and travel areas can change after this dated snapshot.
Treat the zone as a prompt
Zone 1 means high predicted potential at the county scale. Only a test can answer the question for a specific home.
Start with Tennessee’s free test-kit program
TDEC offers free radon test kits to Tennessee homeowners. For a time-sensitive transaction, consider a certified measurement professional.
05 / Quick answers
Greene County radon FAQ
Concise answers where the records are clear, with uncertainty left intact where they are not.
Is Greene County in a high-radon area?
Yes. EPA classifies Greene County as Zone 1, its highest-potential category. That designation describes broad predicted potential, not the reading in a particular house.
Does Greeneville require radon-resistant new construction?
No requirement appears in the available 2018 IRC adoption document. Its appendix list omits Appendix F, Radon Control Methods. The final ordinance number and effective date remain unverified.
Does unincorporated Greene County require it?
No. The county states it uses the 2018 IRC with Appendix J, which covers existing buildings and structures. It does not name Appendix F.
What county readings does the Tennessee dashboard show?
No Greene County-specific average, median, maximum or test count could be verified. The dashboard’s pre/post charts were labeled by health region and showed Northeast Region aggregates.
How many certified professionals are based in the county?
Zero appeared in the NRPP and NRSB directory searches conducted October 16, 2026. The closest NRPP result was 16.7 miles away in Jonesborough; NRSB returned none within 100 miles.
Does Tennessee’s disclosure form mention radon?
Yes. The standard Residential Property Condition Disclosure explicitly names radon gas among possible environmental hazards and advises buyers to consider a radon inspection contingency.