Radon Testing When Buying or Selling a Home in York County, PA

A radon test rarely comes up until a home is under contract — and then it comes up fast, on a clock. If you're buying or selling in York County, here's what Pennsylvania law actually requires, what it doesn't, and where radon fits into a typical closing timeline.

What Pennsylvania law actually requires

Pennsylvania's Real Estate Seller Disclosure Law (68 Pa.C.S. § 7304) requires sellers to complete a property disclosure statement, including a yes/no question on whether hazardous substances — a category that includes radon — are present on the property, and whether it's been tested. What the law doesn't do is require a seller to test in the first place: if a seller has never tested, they answer honestly based on what they actually know, with no legal obligation to go find out before listing. If information later becomes inaccurate before settlement, the seller has to notify the buyer.

In practice, that means a seller who has never tested answers honestly that they haven't — which tells you the home hasn't been checked, not that it's clear.

If you're selling: what actually gets asked of you

You only have to disclose what you know. If you tested years ago and mitigated, disclose the result and the system. If you've never tested, you can say so — there's no requirement to order a test before you list. Some sellers test anyway, specifically because a known low result heads off a buyer's own testing contingency later in the process, and a documented, working mitigation system is a point in the home's favor rather than a liability once it's on paper.

If you're buying: why the timing matters more than the law

A Pennsylvania home inspection contingency runs on whatever window is negotiated into the agreement of sale — there's no statewide standard length, so check your specific contract rather than assuming a default. Radon tests take time regardless of how long that window is: even a short-term test needs a minimum exposure period (commonly 2–7 days) to produce a reliable reading, which means it usually has to start on day one of your inspection period, not partway through it, if you want the result back before your contingency deadline.

Because sellers aren't required to have tested, "the disclosure form doesn't mention radon" tells you nothing about your actual exposure — it just means nobody's checked. With 68% of homes in a state-run York County survey testing above the EPA's action level, an independent test as part of your own purchase process is the only way to know where the specific house you're buying stands. If a result comes back high, that's a negotiating point, not a deal-breaker — radon mitigation is a standard, well-understood fix, and typical installation costs are modest relative to a home purchase.

New construction: do you still need to test?

Yes — and this is the part buyers of new builds most often miss. Pennsylvania DEP's certification rules include an exemption for radon-resistant features installed in new construction before occupancy — the builder doesn't need a DEP-certified radon mitigation contractor to install passive radon-resistant features (like a vapor barrier and vent pipe) during the build itself. But that exemption covers installation before occupancy only. It does not cover testing after you move in, and it does not mean the home is guaranteed to test low. Radon-resistant construction reduces risk; it doesn't eliminate the need to verify with an actual post-occupancy test.

So whether the home is a 1920s rowhome or was finished last month, the same rule applies: a result on paper beats an assumption. Radon testing in York, PA covers what a standard test involves and how to read the number once you have it.

What to do next

• Selling: if you haven't tested and want to head off a buyer request mid-contract, test now on your own timeline instead of under contingency pressure.
• Buying: start your radon test the day your inspection period opens, not partway through it, so the result is back before your deadline.
• New construction: don't assume radon-resistant features mean a guaranteed low result — test after you move in like you would any other home.

Get a Free Radon Estimate — we'll connect you with a PA DEP-certified professional who can test on your closing timeline.