Does Connecticut Require Radon Disclosure in a Home Sale?
Does Connecticut Require Radon Disclosure in a Home Sale?
Yes, with limits. Connecticut requires most sellers of one- to four-unit homes to complete a Residential Property Condition Report, and that form asks whether a radon test has been performed and whether a radon control system is in place. If the seller has a test report, it must be attached. Connecticut does not require sellers to test for radon before listing, and the form only asks for what the seller knows. This article explains what the form covers, what it leaves out, who is exempt and how buyers and sellers can handle radon during a Connecticut sale.
What Connecticut law requires sellers to disclose
The requirement comes from Connecticut General Statutes Section 20-327b. It applies to anyone selling, exchanging or leasing with an option to buy a residential property of one to four units, including condominiums and cooperatives. The seller must give the buyer a written condition report before the buyer signs a binder, purchase contract, option or lease with a purchase option.
The Department of Consumer Protection publishes the official form. The current version, revised in July 2025, includes three radon questions:
- Radon testing. Has a test for radon been performed? If yes, the seller attaches a copy of the report. If no report is available, the seller names the company that did the testing and describes the results.
- Current radon system. Is there a radon control system in place? If yes, the seller explains.
- Recent radon system. Has a radon control system been in place in the previous 12 months? If yes, the seller explains.
The third question addresses a situation that’s easy to overlook. A system that was removed or turned off before listing still has to be disclosed if it was in place during the past year.
What the disclosure does not require
The form asks about radon testing. It doesn’t require it. A seller who has never tested can truthfully answer “no,” and the buyer learns nothing about the home’s current radon level. Connecticut also has no general requirement that a buyer or lender test for radon before closing.
The answers reflect the seller’s knowledge as an owner, not a professional inspection. The form says the seller’s statements are not a warranty to the buyer. It also says the report is not a substitute for inspections, tests and other ways of determining a property’s condition. An old test from a different season, a test taken in an unused part of the house, or a result from before a renovation may not reflect what the buyer will live with.
This matters because radon levels change. Results shift with the season, how the home is heated and ventilated, and changes to the structure. Our guide to radon testing in winter vs. summer explains why a single result is a snapshot rather than a permanent figure.
What happens if a seller doesn’t provide the report
Connecticut doesn’t block a sale when the report is missing. Instead, a seller who fails to provide it must credit the buyer $500 at closing. Some sellers may treat that as a minor cost, but skipping the report doesn’t remove other legal duties a seller may have, and buyers in Connecticut often have their attorney review disclosure issues before closing.
Who is exempt from Connecticut’s condition report
Several kinds of transfers don’t require the report, according to the statute. These include:
- Transfers between co-owners
- Transfers to certain family members without payment
- Newly built homes covered by an implied new-home warranty
- Sales by executors, administrators, trustees and conservators
- Transfers by federal, state or local government
- Transfers connected to foreclosure
Some of these exemptions carry exceptions related to crumbling concrete foundations, which aren’t relevant to radon. The practical result is that estate sales and foreclosures, two common types of transactions, may come with no radon information at all. Buyers in those situations have more reason to arrange their own test.
Why buyers often test anyway
Because the report only shares what the seller already knows, many buyers schedule a radon test during the inspection period. The EPA recommends testing homes at the point of sale, and it recommends fixing a home when radon is at or above 4 pCi/L. It also suggests considering action between 2 and 4 pCi/L. No radon level is considered completely safe, and long-term exposure to radon causes lung cancer.
A test during a sale runs on a tight timeline, so it’s usually a short-term test lasting a few days. To get a valid result, the house needs closed-house conditions, with windows and exterior doors closed except for normal entry and exit, for at least 12 hours before and throughout the test. Many buyers hire a certified radon measurement professional rather than placing a kit themselves, because an independent tester reduces the chance that the result is disturbed or disputed. If you want to understand the devices involved, our radon test kit comparison covers short-term kits, dual kits and continuous monitors.
If a result comes back near the action level, our article on what 4.0 pCi/L actually means explains how to read a borderline number and when a follow-up test makes sense.
Radon in Connecticut well water
Radon can also enter a home through private well water, and the condition report’s radon questions don’t specifically ask about water testing. The Connecticut Department of Public Health recommends testing both air and well water, since water can be elevated even when indoor air is low. The department’s action level for radon in water is 5,000 pCi/L, based on the average of two samples taken at the same time from the same location. Buyers of homes on private wells may want to add a radon-in-water test to their well water testing.
If the test comes back high
An elevated result is usually something to negotiate rather than a reason to walk away. Buyers and sellers commonly agree on a price credit, a repair before closing or an escrow holdback for mitigation. The most common fix for many homes is active soil depressurization, a vent pipe and fan system that draws radon from beneath the foundation and releases it above the roof. Sealing cracks alone is usually not a dependable way to lower significantly elevated radon.
Connecticut requires contractors who perform radon mitigation to hold a state credential along with national certification from the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). After a system is installed, a post-mitigation test confirms whether it brought the level down. Our guide to hiring a certified radon mitigator and our radon contractor checklist cover what to verify before work begins.
For a seller, an existing system with a recent post-mitigation test can be a selling point. It shows a radon issue was identified and addressed, and the condition report gives you a place to explain it.
Radon readings reported in Connecticut
Connecticut homeowners have submitted 91 radon readings to RadonResources.com, from towns including Hamden, West Hartford, Orange and Greenwich. Most of those submissions were at or above 4 pCi/L. That figure doesn’t describe Connecticut homes overall, because people with elevated results are more likely to look for information and share their number. It does show that high readings turn up in many parts of the state. You can browse radon readings homeowners have reported or visit our Connecticut radon page for local context.
Frequently asked questions
Does a Connecticut seller have to test for radon before selling?
No. Connecticut’s condition report asks whether a radon test has been done and requires the seller to attach the report if one exists, but it doesn’t require a new test. A seller who has never tested can answer “no.” Buyers who want to know the current level usually arrange their own test during the inspection period.
Does a Connecticut seller have to disclose an old radon test?
The form asks whether a test has been performed, without limiting the question to recent tests. If a test was done, the seller attaches the report or, if no report is available, names the testing company and describes the results. If you’re unsure how an older or partial result should be reported, a Connecticut real estate attorney can advise you on the specifics.
Does the condition report apply to condos in Connecticut?
Yes. The statute covers residential properties of one to four units, including condominium and cooperative units, unless the transfer falls into one of the listed exemptions. Radon in a condo depends heavily on the unit’s floor and location in the building, so a seller’s past test may not apply to every unit in the complex.
Can a buyer back out over high radon in Connecticut?
That depends on the purchase contract, not on a radon-specific law. Many contracts include an inspection contingency that lets the buyer request repairs, negotiate a credit or end the agreement within a set period. Review the contingency terms with your agent or attorney before the inspection window closes.
Putting the Connecticut rules to work
Connecticut’s radon disclosure tells buyers what a seller already knows: whether the home was tested, what the results were and whether a radon system is or recently was in place. It doesn’t tell anyone what the home’s radon level is today. Sellers who test before listing can answer the form with confidence and address a high result on their own schedule. Buyers who test during the inspection period can make decisions based on a current number rather than a history. If you’re ready to arrange a test or a mitigation estimate, you can connect with a radon professional in your area.
Sources and further reading
- Connecticut General Statutes, Section 20-327b, Residential condition reports (who must provide the report, timing, exemptions, radon questions).
- Connecticut Department of Consumer Protection, Residential Property Condition Report, revised July 2025 (radon questions, $500 credit, no-warranty language).
- Connecticut Department of Public Health, Radon Program and Radon in Your Well Water (5,000 pCi/L water action level).
- Connecticut Radon Program, Connecticut Radon Facts (real estate disclosure, mitigation contractor credentials).
- U.S. Environmental Protection Agency, Home Buyer’s and Seller’s Guide to Radon (point-of-sale testing, closed-house conditions).
- U.S. Environmental Protection Agency, Health Risk of Radon (action level and lung cancer risk).
This article is for general educational purposes and is not legal or medical advice. Disclosure requirements and contract terms can change, and individual transactions may raise questions this article doesn’t address. Consult a Connecticut real estate attorney for legal questions and a certified radon professional for testing or mitigation.
