Does a House Need a Radon Test Before Selling in Lancaster County?
Pennsylvania does not legally require radon testing as a condition of selling a home, but Lancaster County’s EPA Zone 1 designation and 64% elevated-test rate make it a near-universal practice. Buyers almost always request a radon test during their inspection contingency window, and Pennsylvania sellers are legally required to disclose any radon test results they already have on the Seller’s Property Disclosure Statement. If results come back above 4.0 pCi/L, the standard options are seller-installed mitigation before settlement or a credit to the buyer equal to the cost of a PA DEP-certified mitigation system — typically $843–$1,600 in the Lancaster area.
If you’re buying or selling a home in Lancaster County, radon is a conversation you’re going to have. It’s not optional, it’s not a technicality — it’s one of the most common sticking points we see in real estate transactions here, and one of the most misunderstood.
Here’s what you actually need to know.
Why Lancaster County Has a Radon Problem
Radon is a naturally occurring radioactive gas that seeps up from uranium-bearing rock into homes through foundation cracks, floor drains, and other openings. You can’t smell it, see it, or taste it. And it’s the second leading cause of lung cancer in the United States, after smoking.
Pennsylvania has one of the most serious radon problems of any state in the country — an estimated 40% of Pennsylvania homes have radon levels above the EPA’s action guideline of 4 picocuries per liter (pCi/L).
Lancaster County is even more extreme. Testing data from 1986 to 2016 shows that 64% of Lancaster County homes that have been tested came back above that same EPA threshold — out of more than 20,000 tests. The EPA classifies all of Lancaster County as Zone 1, the highest-risk designation, predicting average indoor radon levels above 4 pCi/L.
What does that mean for a buyer or seller here? It means you should assume radon is a factor until you know otherwise.
Is Radon Testing Required When Selling a Home in PA?
No, Pennsylvania does not legally require radon testing as a condition of sale. But that doesn’t mean it won’t come up — it almost always does.
Here’s why:
Pennsylvania’s Real Estate Seller Disclosure Law requires sellers to disclose all known radon test results on the Seller’s Property Disclosure Statement. If you’ve had your home tested before, those results must be disclosed before the buyer signs the Agreement of Sale. You can’t hold them back.
On the buyer side, radon testing is almost always requested during the inspection contingency window — the 10- to 15-day period after an accepted offer when buyers conduct their due diligence. If you’re buying a home in Lancaster, Lititz, Manheim Township, Hempfield, or anywhere else in the county, your agent will almost certainly recommend radon testing as part of your inspection.
If you’re working through the home buying process in Lancaster, PA, this is one of the steps that matters more here than almost anywhere else in the country.
How Radon Testing Works During a Home Sale
For real estate transactions in Pennsylvania, radon testing must follow PA DEP protocols — specifically, the short-term test under closed-house conditions.
What that means in practice:
- A certified radon tester places a continuous radon monitor or charcoal canister in the lowest livable level of the home — typically the basement
- The home must remain in “closed house” conditions (windows and exterior doors kept closed, except for normal entry and exit) for at least 12 hours before and throughout the 48–96 hour test period
- The tester retrieves the device, processes the results, and produces a certified test report
Professional radon testing through a PA DEP-certified tester typically costs $150–$300 and takes 48–96 hours. You can buy a do-it-yourself test kit at a hardware store for $20–$30, but those don’t meet the contractual requirements for a real estate transaction contingency. For a real estate deal to move forward based on the test results, you need a certified test.
One important note for sellers: if your home already has a radon mitigation system installed, disclose it on the Seller’s Property Disclosure Statement. A well-maintained system is actually a selling point — it shows the issue was addressed professionally.
What Happens If the Test Comes Back Above 4.0 pCi/L
This is where most buyers and sellers get nervous. A test result above the EPA action level doesn’t kill the deal. In most cases, it’s a resolved issue within a few days of negotiation.
There are two standard paths:
Option 1: Seller installs a mitigation system before settlement
The seller hires a PA DEP-certified radon mitigation contractor to install an Active Soil Depressurization (ASD) system — the most common and effective type of mitigation. The contractor runs a pipe from below the foundation through the basement and out through the roof or sidewall, creating negative pressure that pulls radon gas out of the soil before it enters the home.
After installation, a post-mitigation test confirms that levels have dropped below 4.0 pCi/L. When the buyer’s contingency specifies this confirmation, the seller must meet that threshold — not just install a system.
Option 2: Seller provides a credit, buyer mitigates after closing
The seller offers a credit at settlement equal to the estimated mitigation cost, and the buyer handles it after closing. This is often faster and avoids scheduling delays near the settlement date.
In Lancaster County, mitigation typically costs $843–$1,600 for a standard residential installation, depending on the home’s construction and foundation type. For a $500,000 home, that’s a relatively small number relative to the transaction — and most deals proceed once this is negotiated.
One critical requirement: the mitigation contractor must hold current PA DEP certification. If you hire an uncertified contractor, the installation cannot satisfy a real estate contingency clause under Pennsylvania law. This isn’t optional.
Understanding what sellers pay at settlement in Lancaster County is part of the same conversation — a radon mitigation credit is often one of the line items that shows up on your settlement statement if it wasn’t handled before listing.
What Sellers Should Think About Before Listing
If you’re getting ready to sell your home in Lancaster County, you have a few choices before you put a sign in the yard.
Test before listing. A pre-listing radon test tells you exactly what you’re working with. If levels are below 4.0 pCi/L, you have a clean result you can disclose proactively — which builds buyer confidence and eliminates radon as a negotiating chip. If levels are above 4.0, you can install a mitigation system before listing, disclose the post-mitigation results, and market your home with confidence.
Price it in if you don’t fix it. If you know about elevated radon and choose not to mitigate, you must disclose the results. Buyers will factor in the mitigation cost when they make their offer — and they often ask for a credit that exceeds the actual installation price. Handling it upfront is almost always the better financial move.
Understand your disclosure obligation. If you’ve never tested, you have nothing to disclose. But once you have results — whether from a test you ordered or one the buyer orders during their contingency — those results become part of the transaction. Sellers who test before listing control the narrative. Sellers who learn the results for the first time from a buyer’s test are negotiating under a deadline.
This is exactly the kind of conversation I have with every Lancaster County seller before we go to market. Your specific situation — home age, foundation type, existing systems, and target price — determines which approach makes the most sense.
What Buyers Should Do
If you’re buying a home in Lancaster County, include radon testing in your inspection contingency. Name it specifically — don’t assume it’s covered under a general inspection clause. Work with your agent to set a threshold (typically 4.0 pCi/L per EPA guidance) and define what the seller must do if that threshold is exceeded.
Don’t waive radon testing to strengthen your offer without understanding what you’re giving up. A mitigation system costs $843–$1,600. Elevated radon levels over years of exposure carry health consequences that can’t be undone. The test window is short — 48 to 96 hours — and it won’t delay your closing if it’s scheduled at the start of your inspection period.
If you’re also navigating the home appraisal process, keep in mind that radon doesn’t affect appraised value. But a documented, professionally installed mitigation system can be noted as a home improvement — and it removes a potential future negotiating point for subsequent buyers when you eventually sell.
The short version: in Lancaster County, radon testing is part of how a real estate transaction works. Build it into your timeline and your contingency language, and it won’t be a surprise.
Frequently Asked Questions
Does radon testing delay a home sale in Lancaster County?
Not if it’s scheduled promptly. Radon testing takes 48–96 hours under closed-house conditions and is typically completed early in the 10- to 15-day inspection contingency period. If results are elevated, negotiating a mitigation credit or scheduling a PA DEP-certified installation adds a few days but rarely disrupts settlement timelines.
Who pays for radon testing and mitigation in a Pennsylvania home sale?
Buyers typically pay for the radon test ($150–$300) as part of their inspection costs. If results come back above 4.0 pCi/L, whether the seller pays for mitigation — or provides a closing cost credit instead — is negotiated through the Agreement of Sale. In Lancaster County, mitigation systems typically cost $843–$1,600.
Is a radon mitigation system a deal-breaker for buyers?
Rarely. In Lancaster County, where more than 60% of homes have tested above EPA action levels, buyers and agents understand that mitigation is common and effective. A properly installed PA DEP-certified system that produces post-mitigation results below 4.0 pCi/L is a resolved issue — not a red flag.
What is the PA DEP radon certification requirement for real estate transactions?
Pennsylvania law requires that contractors who perform radon mitigation as part of a real estate transaction hold current PA DEP mitigation certification. Hiring an uncertified contractor means the installation cannot satisfy a contingency clause in the Agreement of Sale. Always verify certification before hiring.
Does a home with a radon mitigation system sell for less?
Not typically. A properly installed and documented mitigation system shows that the radon issue was addressed professionally. Many buyers see it as a positive — the work is already done, and they won’t need to negotiate for it. The system should be disclosed on the Seller’s Property Disclosure Statement and maintained in working order.
Radon is not a reason to panic, and it’s not a deal-breaker. But given that Lancaster County has one of the highest radon test rates in Pennsylvania, it belongs on every buyer’s and seller’s checklist — not as an afterthought, but as a standard part of the process.
If you’re getting ready to buy or sell a home in Lancaster County and have questions about how radon fits into your specific situation — whether that’s how to structure a contingency, manage a seller credit, or decide whether to test before you list — I’m glad to walk you through it. Reach out anytime.
About Craig Hartranft
Craig Hartranft is a top-ranked Lancaster County REALTOR® and Founder of The Craig Hartranft Team, Berkshire Hathaway’s #1 real estate team in Lancaster County, with 460 homes sold and $195M+ in sales in 2025, plus over 1,400 five-star reviews across Google and Zillow.