Radon in Illinois · home sales
Illinois radon disclosure: what the Radon Awareness Act requires
Before a buyer signs, an Illinois seller hands over an IEMA pamphlet and a radon disclosure form. Testing stays optional. These are the rules, each linked to the statute or rule text.
What the seller must give the buyer
- Pamphlet and disclosure form
- Before a buyer is bound by a purchase contract, the seller must give the buyer the IEMA pamphlet Radon Testing Guidelines for Real Estate Transactions and the Illinois Disclosure of Information on Radon Hazards form.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Seller shares known results
- A seller must hand over any radon test results in their possession that show elevated levels in the home.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Form covers past mitigation
- On the form the seller initials whether elevated radon is known, or whether they have no knowledge of it or earlier elevated levels were mitigated.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Late disclosure before acceptance
- If the disclosures come after the buyer has made an offer, the seller must finish them before accepting the offer and let the buyer review and possibly amend it.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Property disclosure report radon line
- The general Residential Real Property Disclosure Report also asks the seller whether they are aware of unsafe radon levels on the premises.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
What the Act does not require, and who it covers
- No seller testing requirement
- The Radon Awareness Act does not require a seller to test for radon or to mitigate.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Covers one to four units
- The Act covers sales of homes and lots with one to four dwelling units, including manufactured housing lots.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Third floor units excluded
- Dwelling units on the third story or higher, such as many condominium units, are excluded from the Act.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
If the buyer tests during the sale
- Use a licensed tester for sales
- IEMA's real estate guidelines tell buyers and sellers not to rely on a radon result from anyone other than a licensed measurement professional or technician.Illinois Emergency Management Agency and Office of Homeland Security (IEMA-OHS), read October 15, 2026
- Home inspectors need the radon license
- A home inspector who runs radon tests for clients needs an IEMA-OHS measurement license. The only retail exemption excludes sellers that also serve the client through home inspection or real estate representation.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Simultaneous test option
- For a sale, the Illinois rule allows simultaneous testing: at least two similar detectors placed together and exposed for the same period, with the average used to decide on mitigation.Illinois General Assembly, Joint Committee on Administrative Rules (Illinois Administrative Code), read October 15, 2026
- Continuous monitor option
- The second real estate option is a continuous monitor that records at least hourly, run for at least 48 hours.Illinois General Assembly, Joint Committee on Administrative Rules (Illinois Administrative Code), read October 15, 2026
- Test each lowest area
- A test is required in each of the lowest structural areas suitable for occupancy, so a house with a basement and a crawl space area gets a test in each.Illinois Emergency Management Agency and Office of Homeland Security (IEMA-OHS), read October 15, 2026
- Closed house 12 hours before
- Windows and doors stay closed starting at least 12 hours before a short term test and throughout it.Illinois Emergency Management Agency and Office of Homeland Security (IEMA-OHS), read October 15, 2026
- Results due within 45 days
- The tester must give the client the radon test results within 45 days after testing.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Mitigators cannot test own work
- A mitigator who also holds a measurement license may not do the before or after tests at a house where they installed the system, unless another independent person has measured.Illinois General Assembly, Joint Committee on Administrative Rules (Illinois Administrative Code), read October 15, 2026
Renting in Illinois
- Landlords give tenant pamphlet
- Landlords must give tenants and applicants the IEMA pamphlet Radon Guide for Tenants, any records showing a radon hazard in the unit, and the tenant radon disclosure form.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
- Tenant 90 day test right
- A tenant has 90 days from the start of the lease to test. If the result exceeds the IEMA action level and the landlord chooses not to mitigate, the tenant may end the lease.Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026
EPA's guidance for buyers and sellers
EPA's Home Buyer's and Seller's Guide applies in every state; the state rules above come first where they differ.
- Three short-term sale options
- For a home sale, EPA's buyer and seller guide accepts any of three short-term testing options to decide whether to fix.U.S. Environmental Protection Agency, read October 15, 2026
- Buyer may ask for retest
- A buyer may ask for a new test, for example when the seller's test is more than about two years old.U.S. Environmental Protection Agency, read October 15, 2026
- Sale test placement
- In a sale, the test device goes in the lowest level that could be used regularly, finished or not.U.S. Environmental Protection Agency, read October 15, 2026
- Contract: who pays mitigation
- EPA suggests buyers consider contract terms for the radon test, including when any mitigation happens and who pays for it.U.S. Environmental Protection Agency, read October 15, 2026
Have a number already? Read your result on EPA's scale. Need a licensed mitigator before closing? Illinois's license list. Hiring an inspector for the sale? Illinois home inspector rules.
Sources
- Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026.
- Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026.
- Illinois Emergency Management Agency and Office of Homeland Security (IEMA-OHS), read October 15, 2026.
- Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026.
- Illinois General Assembly, Joint Committee on Administrative Rules (Illinois Administrative Code), read October 15, 2026.
- U.S. Environmental Protection Agency, read October 15, 2026.
- U.S. Environmental Protection Agency, read October 15, 2026.
This page explains the rules; it is not legal advice for a particular contract.