If you’re closing on a house in Elizabethtown or anywhere in Hardin County, radon testing is probably sitting somewhere in your contract contingencies right now — and most buyers and sellers have no idea what the test actually involves or how it can affect the closing date. Here’s what the process looks like from contract to closing table.
Do I need a radon test before closing on a house in Kentucky?
Kentucky law does not mandate radon testing before every sale, but most purchase contracts written through standard Kentucky Realtors forms include a radon testing contingency, and lenders or buyers frequently request it voluntarily given the state’s well-documented radon levels. Sellers must also disclose known radon test results under KRS § 324.360.
In practice, the contingency usually gives the buyer a set window — often 10 to 14 days, though this varies by contract and should be confirmed with your agent — to order a test and review results before the inspection period closes. If you want the full disclosure-law breakdown, see our guide on Kentucky’s real estate radon disclosure requirements.
Who pays for radon testing and mitigation during a Kentucky real estate closing?
There is no statewide rule assigning who pays for radon testing or mitigation in a Kentucky home sale — it is negotiated in the purchase contract, and local custom varies by county and even by transaction, so confirm the split with your agent before signing.
In many Hardin County transactions, the buyer orders and pays for the initial test since it’s part of their due-diligence period, and then negotiates with the seller over who covers a mitigation system if results come back elevated. Some contracts cap the seller’s repair obligation at a dollar amount; others simply give the buyer the right to walk away. Because this is a negotiated term rather than a legal mandate, read your specific contract language — don’t assume either party’s obligation based on what a friend’s deal looked like.
How long does a radon test take before a closing date?
A real-estate radon test requires a minimum 48-hour continuous measurement period under closed-house conditions, following the ANSI/AARST MS-PC-2019 protocol used by certified testers nationwide, plus time to place and retrieve the device and process results — so plan for roughly three to five business days total.
Closed-house conditions mean windows and exterior doors stay shut except for normal entry and exit, starting at least 12 hours before the test begins and continuing through the full measurement period. In older homes around Downtown Elizabethtown and Freeman Lake area with basements or crawl spaces, the device typically goes in the lowest level anyone uses regularly — not a true unoccupied crawl space — placed at least 20 inches above the floor and away from exterior walls, windows, and HVAC vents per the measurement protocol. If a seller or occupant opens windows during the test window, most certified testers will flag or invalidate the results, which can cost the transaction days it may not have.
Continuous monitors vs. passive test kits
Real estate transactions typically use a continuous radon monitor (CRM) rather than a mailed charcoal canister. A CRM records hour-by-hour data with time stamps and tamper indicators, which gives both parties’ agents a verifiable chain of custody — something a passive canister test can’t offer in a fast-moving closing timeline.
What radon level triggers mitigation before closing in Kentucky?
The U.S. Environmental Protection Agency sets 4 picocuries per liter (pCi/L) as the action level at which mitigation is recommended, a threshold referenced by EPA’s radon program nationwide, including in Kentucky’s high-radon-potential counties. Many real estate contracts in Hardin County and across the state use this same 4.0 pCi/L number as the contractual trigger for renegotiation or mitigation.
Results between 2 and 4 pCi/L don’t carry the same mandatory trigger but are often still discussed between buyer and seller, since EPA itself notes risk exists below 4 pCi/L — it’s just not the formal action threshold. If a test lands above 4.0 pCi/L, the next contractual step is usually either mitigation by a licensed operator before closing or a credit so the buyer can arrange it after taking possession.
Can a home sale fall through because of radon test results?
Yes — a radon test above the contract’s stated threshold can delay or void a Kentucky home sale if the contingency gives the buyer a right to cancel, renegotiate repairs, or request a credit, and the parties can’t agree on next steps within the inspection period deadline.
Most disputes resolve with mitigation rather than a canceled contract, since a sub-slab depressurization system is a routine, well-understood fix and most sellers would rather install one than lose a buyer. The licensed operators in our network handle system installation after test results come back, and can usually schedule around a tight closing timeline — but confirm installation lead time with the provider directly, since scheduling varies by season and current workload.
This article is general information for homebuyers and sellers in Kentucky, not legal advice. Radon testing contingencies, disclosure obligations, and repair-cost allocation are governed by your specific purchase contract and applicable Kentucky statute; consult your real estate agent or an attorney for guidance on your transaction.