Should you test your Sewickley home for radon before you list it, or let the buyer handle it during inspection?
Most sellers treat this as a formality, if they think about it at all. The instinct is to skip the pre-listing test. Pennsylvania's disclosure law doesn't require it, and testing before you have a buyer feels like inviting a problem you might not otherwise have to put in writing. That instinct makes sense on its own terms. It's also backwards, and the reason has less to do with radon itself than with who controls the calendar once a contract is signed.
What Pennsylvania's Disclosure Law Actually Requires
Pennsylvania's Real Estate Seller Disclosure Law, codified at 68 Pa.C.S. § 7301 et seq., puts the seller's duty at § 7303. The disclosure form itself, the Seller's Property Disclosure Statement, treats radon as a hazardous substance item under § 7304(B)(14). The obligation is narrow. Sellers must disclose radon test results they know about. The statute does not require anyone to test in the first place.
That distinction is the whole loophole. A seller who has never ordered a test has, technically, nothing to disclose on that line of the form. No test, no known result, no violation. Pennsylvania has required this kind of disclosure since 2000, part of a wave of state radon rules that followed a 1984 case in Limerick, Montgomery County, where a nuclear plant construction worker set off radiation monitors on his way into work because of radon levels in his own house, not the plant. The law exists because radon is a documented issue across much of the state, and the question of whether to test before listing sits in the space the statute leaves open for each seller to decide.
Why Allegheny County Makes That Gap Smaller Than It Looks
Sewickley sits in Allegheny County, which the EPA classifies as Radon Zone 1, meaning the predicted average indoor screening level exceeds 4 picocuries per liter, the threshold at which the agency recommends mitigation. Pennsylvania carries this designation across 49 of its 67 counties. According to the Pennsylvania Department of Environmental Protection, roughly 40 percent of homes tested statewide come back above that 4.0 pCi/L action level. The EPA has also set a secondary 2.0 pCi/L level at which mitigation is worth considering, well below where most sellers assume the conversation even starts.
None of that changes what the disclosure form asks a seller to certify. It does change what happens after the form is signed, because a buyer purchasing in a Zone 1 county rarely skips the test just because the seller did.
The Buyer Tests Anyway
Standard Pennsylvania agreements of sale build in an inspection contingency, typically 10 to 15 days, during which the buyer can order any testing they want, radon included. A short-term charcoal canister test needs 48 to 96 hours under closed-house conditions to produce a reliable reading, and a DEP-certified lab typically turns results around in another 24 to 48 hours. Stack those windows together and a buyer who orders a test on day two of a ten-day contingency can have results in hand before the contingency period even closes.
The Pennsylvania Association of Realtors treats radon testing as close to routine in the state's high-radon counties, and its guidance to member agents spends less time on whether a buyer will test and more on making sure the seller doesn't do anything that could throw off the reading, like running attic fans or leaving windows open during the closed-house window.
So the seller who skipped the pre-listing test hasn't avoided the radon conversation. They've moved it into the ten days after they already have a signed contract, with a buyer holding a contingency and an exit if the number comes back high.
Same Conversation, Different Leverage
What actually changes is not whether the test happens. It's who is standing where when the number comes back.
| Test before listing | Wait for buyer's test | |
|---|---|---|
| Who sets the timeline | Seller, weeks in advance | Buyer, inside a 10 to 15 day window |
| Contractor selection | Seller can compare quotes | Often whichever certified contractor can schedule fastest |
| Result if elevated | Priced in or fixed before the home hits the market | Renegotiated mid-contract, sometimes with a walk-away clause in play |
| Disclosure once a result exists | Must be disclosed either way | Must be disclosed either way |
That last row is the part sellers tend to miss. Once a test exists, the duty to disclose an elevated result attaches whether the test happened in March before the sign went up or on day six of a signed contract. Testing early doesn't create legal exposure that testing late avoids. It just changes who is in control when the result lands.
What Fixing It Actually Costs
Radon mitigation in Pennsylvania commonly runs $800 to $2,500, depending on foundation type and system design, and the work has to be done by a contractor holding active certification through the PA DEP's Bureau of Radiation Protection under Act 43. There's no grandfather provision for uncertified installers. A system installed by someone without that credential won't satisfy a mitigation contingency written into an agreement of sale, no matter how well it actually lowers the reading.
A seller who tests before listing has room to get two or three quotes, pick a contractor on their own schedule, and treat the fix the way they'd treat any other pre-sale improvement, priced and finished before a buyer ever walks through the door. A seller negotiating mid-contract is usually choosing from whoever the buyer's inspector recommends and whoever can start soonest, which is rarely the same contractor who'd have offered the best price with more notice.
The Part the Disclosure Form Doesn't Erase
Pennsylvania gives buyers up to two years after settlement to bring a claim under the disclosure law if a seller is later found to have known about and withheld a material defect. That clock only starts on results a seller actually possessed. A seller who genuinely never tested has nothing on record to have withheld, and that protection is real. It's also the only thing the don't-test approach buys. It doesn't stop the buyer's own test from happening, and it doesn't give the seller any say in when that test lands or who gets hired to fix what it finds.
For a homeowner deciding what to handle before a Sewickley listing goes live, radon deserves the same treatment as any other pre-listing question: something to evaluate on the seller's own timeline, not something to leave for whoever shows up with an inspection report. That's the same lens worth applying to the broader set of pre-listing and relocation questions that come up before a home in the Quaker Valley corridor goes to market, and it applies just as directly to a radon test as it does to a repair or an update.
A Few Questions Worth Asking Before You List
Does a mitigation system hurt resale value? Not typically. A documented, working system signals that a known issue was addressed by a certified professional, which tends to reassure buyers more than it deters them.
Can any contractor do the mitigation work? Only if you want the result to hold up in a contract. Pennsylvania requires active DEP certification under Act 43 for anyone performing mitigation for compensation, with no exception for otherwise capable but uncertified installers.
What if I test and the result comes back low? Then you have a documented result to disclose showing the home tested below the action level, which closes the question before a buyer ever raises it.
Before your Sewickley home goes on the market, it's worth finding out what a radon test, or any other pre-listing decision, actually means for your number and your timeline. The Monica Sample Group can walk through that with you before you list, not after you're already under contract. Request a Free Home Valuation to start that conversation on your own schedule.
