Selling or Buying a Home With Radon in Pennsylvania: What York County Buyers and Sellers Need to Know

Radon comes up in nearly every York County home sale, and it causes more last-week contract stress than almost anything else in the inspection process. Here is how it actually works in Pennsylvania.

Disclosure: Pennsylvania's Real Estate Seller Disclosure Law requires sellers to disclose known material defects, and the state's standard disclosure form specifically asks about radon test results and mitigation systems. If you have tested, you must disclose the result. If you have never tested, the law does not force you to test — but nearly every buyer's agent in York County will request one during the inspection contingency, so it is coming either way.

Testing during the sale: buyers typically order a 48-hour continuous monitor test from a PA DEP-certified tester, placed in the lowest livable level under closed-house conditions. Results are usually emailed the day the monitor is retrieved. A reading at or above 4.0 pCi/L triggers a request for mitigation.

Who pays: there is no law. In practice, York County sellers almost always install the system before closing, because the buyer's alternative is to walk and the next buyer will test too. A typical system costs $900–$2,000, which is far less than a lost sale. Some deals settle on a credit instead; buyers should be cautious with that, because they then own the scheduling problem after moving in.

Timeline: a certified mitigator can usually do the diagnostic visit within a day or two, install within the week, and place the post-mitigation test 24 hours after install. Build in about ten days from the high test result to a verified passing number. Tell your mitigator the closing date up front.

Buying a home that already has a system: this is a good thing, not a warning sign. A house with a labeled, manometer-equipped system and a passing post-mitigation report is a house where the radon question has been answered. Have the inspector confirm the fan is running (manometer columns uneven), the exhaust terminates above the eave, and the system has a label with a certification number. Ask for the most recent test; if it's more than two years old, run a new one.

Sellers who want the smoothest path: test before listing. If the result is high, install the system on your own schedule, disclose the passing post-mitigation result, and take the most common contingency off the table entirely.