Should You Test for Radon When Buying a Home in Montgomery County, PA?
Yes. Pennsylvania has one of the most serious radon problems in the United States, and the state Department of Environmental Protection (DEP) estimates that about 40 percent of Pennsylvania homes have radon above the EPA action level of 4 picocuries per liter (pCi/L). A radon test during your inspection period is inexpensive, and if the result is high, a mitigation system typically costs less than $1,500 to install. That makes radon one of the most fixable issues a buyer can find.
What is radon and why is it a concern in Pennsylvania?
Radon is a natural radioactive gas that forms when uranium in soil and rock breaks down. It can seep into a home through cracks in the foundation, floor drains, and other openings, then build up indoors. You cannot see, smell, or taste it, so testing is the only way to know.
Radon matters because long-term exposure raises the risk of lung cancer. According to the American Lung Association, radon is the second leading cause of lung cancer in the U.S. and the leading cause among people who have never smoked.
How common is radon in Montgomery County?
A regional radon mitigation company's summary of surveyed homes puts Montgomery County at about 33 percent above 4 pCi/L, with another 24 percent between 2 and 3.9 pCi/L. Neighboring counties in that same summary range from about 26 percent (Delaware County) to 43 percent (Chester County).
Those are averages. Radon levels can differ a lot between two homes on the same street, so the only number that matters is the one from the house you are buying. The DEP also publishes radon test results by zip code if you want a sense of your area.
When and how do I test for radon when buying?
Timing: Order the test during your inspection period, right alongside your home inspection, so you have results before your contingency deadline.
Who tests: Use a tester certified by the Pennsylvania DEP. Many home inspectors are certified and can place the test during the inspection.
How it works: A short-term test runs for at least two days in the lowest livable level of the home, usually the basement. The house should stay closed up during the test.
Results: You will usually have results within a few days, in time to negotiate.
What radon level is too high?
The EPA and the Pennsylvania DEP recommend taking action at 4 pCi/L or higher. The DEP notes that if a short-term result comes back between 4 and 8 pCi/L, a second test can help confirm the level. In a purchase, buyers usually do not have time for a long-term test, so most negotiate based on the first professional result.
Levels between 2 and 4 pCi/L are below the action level, but there is no completely safe level of radon. Some buyers choose to mitigate in that range for peace of mind.
How much does radon mitigation cost?
According to the Pennsylvania DEP, a permanent radon mitigation system generally costs between $800 and $1,200. In our area, we find that they are between $1,100 and $1,500. Most systems use a pipe and an exterior or attic fan to pull radon from beneath the foundation and vent it above the roofline. Installation usually takes about a day, and you should hire a DEP-certified mitigation contractor.
What if the home already has a radon system?
That is a good sign, but still test. Check that the fan is running and that the gauge on the pipe (called a manometer) shows the system is working. The DEP recommends retesting homes with mitigation systems every two years.
Who pays to fix high radon?
It is negotiable. Common outcomes include:
The seller installs a mitigation system before closing and provides a post-mitigation test
The seller gives a credit so you can install the system yourself after closing
The price is adjusted to reflect the cost
Because mitigation is predictable and relatively affordable, high radon rarely needs to be a deal breaker. We help buyers request the outcome that fits their timeline and comfort level.
Should high radon make me walk away from a house?
Usually not. Unlike many inspection findings, radon has a clear, proven fix with a known price range. What matters is that you test, understand the result, and negotiate before your inspection contingency ends.
Buy with fewer surprises.
The Shaina McAndrews Team at eXp Realty has more than 10 years of experience guiding Montgomery County buyers through inspections, radon testing, and repair negotiations. We are licensed in PA and NJ, and we plant a tree for every home we close (more than 1,000 so far). Book a quick call and we will walk you through how we protect you during the inspection period.
Schedule a Buyer Strategy Consultation
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Call or text 215.767.7150 or visit MontCoLiving.com.
Sources
Pennsylvania Department of Environmental Protection, Radon in the Home
Pennsylvania DEP Radon Action Month guidance, as reported by WPXI (mitigation cost and retesting)
American Lung Association radon findings, as reported by CBS News Pittsburgh
Pennsylvania Association of Realtors, Nearly 40% of Pennsylvania Homes Tested Have Radon
RadonRid, county radon survey summary for southeastern Pennsylvania
