Should I Test for Radon When Buying a House in Massachusetts?
Yes, it's inexpensive and worth adding to the inspection. What a radon test tells you, what happens if the level is high, and what sellers should have ready if the home already has a mitigation system.
Yes. Radon is a natural, odorless gas that can build up in basements and lower levels, and the only way to know the level is to test. A test costs little next to everything else in the purchase, runs during your inspection period, and a high result is usually fixable with a mitigation system. It's rarely a reason to walk away. It's a reason to negotiate.
How does a radon test work?
Your home inspector or a radon tester places a monitor on the lowest livable level, usually for at least 48 hours, with windows and doors kept closed. The result is reported in picocuries per liter (pCi/L). The U.S. EPA recommends fixing a home at 4 pCi/L or higher and suggests considering it between 2 and 4.
Book the test at the start of your inspection period so the result comes back before your inspection deadline.
What happens if the result is high?
- Get a mitigation quote. Most systems use a pipe and fan to pull air from under the slab and vent it above the roof.
- Negotiate. Common outcomes are the seller installing a system before closing or giving a credit toward one. Your attorney writes it into the agreement.
- Retest after mitigation to confirm the system works.
What if the home already has a system?
That's a good sign, as long as it works. Ask for:
- The installation paperwork, and
- A post-mitigation test result showing the level came down.
Check that the fan is running. Most systems have a gauge (a manometer) on the pipe.
What should sellers have ready?
If you've tested or installed a system, put the paperwork together before you list. When I list a home that's had radon mitigation or a prior repair, like a sealed foundation crack, I offer the documentation to buyers' agents up front. Buyers trust what they can read.
Questions people actually ask.
Is radon common on the North Shore?
Levels vary house by house, even on the same street. That's why you test the house you're buying instead of relying on the neighborhood.
Does Massachusetts require radon testing to sell?
No statewide test is required for a sale. Buyers choose to test during the inspection period.
Can I test the water too?
Homes on private wells can have radon in the water. Ask your inspector about a water test if the home has a well.
This article is general information about Massachusetts real estate, not legal, tax, or financial advice. Every property and transaction is different. For advice on your situation, talk with me and, where appropriate, an attorney, lender, or tax professional.