Radon in an Illinois home sale
Most Chicagoland radon decisions happen with a contract clock ticking. Here is how the law actually allocates responsibility, what remains pure negotiation, and the playbooks that keep a 4.7 pCi/L result from becoming a dead deal.
What Illinois law requires — precisely
The Illinois Radon Awareness Act makes radon a disclosure matter in residential sales: sellers provide buyers the state’s radon pamphlet and disclose known elevated results or prior testing information. That’s the legal core. What the Act does not do is force anyone to test, or force a seller to fix an elevated result — those choices belong to the parties and their contract.
The buyer’s playbook
- Test during the inspection window. Radon isn’t bundled into a standard home inspection — request it explicitly; transaction tests are performed by IEMA-licensed measurement professionals, typically with 48-hour continuous monitors.
- Elevated result? Price it immediately. A written mitigation quote — commonly low four figures — turns fear into a figure inside your window.
- Ask for one of three remedies: seller-managed installation with a verification retest before closing, a credit equal to the quote, or a price adjustment. Rank them with your attorney; all three close deals every week here.
- If the seller won’t move, decide like an owner: you can install the same system after closing for the same quote. Walking away over a mitigatable number is sometimes right — but only when the rest of the deal was marginal anyway.
The seller’s playbook
- Disclose what you know, fully. Old test results included. Illinois requires it, and discovered surprises cost more than disclosed ones.
- Consider testing before listing. A pre-listing test keeps the timeline yours: mitigate calmly at market pace, or price the disclosure in — either beats a mid-contract scramble.
- If a buyer’s test comes back elevated, counter with data: your own quote in hand converts their inflated repair ask into a documented number.
- If you install, keep the paper. The scope of work, the license number, and the post-mitigation retest become part of the house’s story — and your next disclosure’s best page.
Deadline mechanics worth respecting
Chicagoland contracts commonly run inspection and attorney-review periods measured in business days, and radon answers must fit inside them. The workable rhythm: test result in hand by mid-window, quote within a day or two (contractors here quote from reports and photos routinely), negotiation posture set before the window closes. Tell every bidder your deadline in the first message — see the quote form’s timeline field, built for exactly this.
Common questions
Can a seller refuse the buyer’s request to mitigate?
Yes — and the buyer can respond with a credit demand, a price renegotiation, acceptance, or (contract permitting) walking away. Radon sits in the same negotiation bucket as any inspection finding. What a seller cannot do is un-know the result: it must be disclosed to future buyers, which is why refusing a low-four-figure fix rarely survives a second listing cycle.
Who pays for the mitigation in a typical Chicagoland deal?
There is no statutory answer — it lands where negotiation puts it, and local custom splits between seller-managed installs (buyers like the certainty of a verified retest before closing) and credits at closing (sellers like the speed, buyers like choosing their own contractor). The written quote is what both versions are priced against.
Does a radon disclosure or a mitigation system scare buyers off?
A mitigated home with documentation typically reads as maintained, not damaged — the system removes a common inspection surprise. What genuinely spooks buyers is an undisclosed history surfacing late. Disclosure plus a verified system is the strong position; disclosure plus a written quote is a workable one; surprise is the only losing posture.
We’re under contract on new construction. Is radon still a thing?
Yes — tight new homes can hold soil gas effectively, and builders in this region frequently include passive rough-in pipes rather than active systems. Test like any other purchase; if elevated, activating the rough-in (adding a fan) is usually a modest scope your attorney can put on the builder or price into the deal.
Sources
- Illinois General Assembly — Illinois Radon Awareness Act (420 ILCS 46)
- U.S. EPA — Home Buyer’s and Seller’s Guide to Radon
- IEMA-OHS — Illinois Emergency Management Agency and Office of Homeland Security — Radon Program
- Illinois General Assembly — Radon Industry Licensing Act (420 ILCS 44)
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