Buying and selling a home
There is a radon issue in my transaction. What happens now?
Outside a transaction, radon is a house problem with no deadline. Inside one it becomes a contract problem, and the contract is what makes it urgent — not the gas, which has been there for decades.
That changes the correct order of operations. The first question in a live deal is almost never "what does this number mean"; it is "how many days do I have, and what still fits inside them".
Who this is for. A buyer, a seller, or an agent working a live deal, usually with a contract clock already running.
The reading order
5 steps, 22 resources. Nothing below is written here — every link goes to the page that holds the substance, and the note under each one says what it adds at that point in the sequence. A hub that restated its own links would just be competing with them.
Before anything is listed or offered
The cheapest version of this entire situation is a test that happens before there is a contract to disrupt.
- Selling or buying? Tool
Works through whether to test before listing, and what a pre-listing result obliges you to do with it.
- Should a seller install before listing Guide
The case for and against pre-emptive work, including the scenarios where it costs a seller money for nothing.
- Selling Checklist
Printable, for the weeks before a listing goes live.
- Buying Checklist
Printable, for a buyer whose inspection window has not opened yet.
- Save the result to a permanent record Page
Assemble the testing and mitigation history onto one sheet before the disclosure conversation, not during it. Missing installer details and warranty wording are what turn a disclosure into a re-test under deadline.
- Selling or buying? Tool
When a result lands mid-deal
The days you have left determine which options are even available, which is why the timeline comes before the negotiation.
- A failed test, right now Page
The immediate triage: what has to happen this week and what can wait.
- Radon sequence in a transaction Diagram
Which stages are fixed and which are negotiable, drawn so you can see where the days actually go.
- Failed test during inspection Guide
The specific case of a result arriving inside an inspection contingency, which is where most of these start.
- Radon in a real-estate transaction Page
The full sequence, from contingency through amendment to closing documentation.
- A failed test, right now Page
The negotiation
This resolves in a small number of recognisable ways. Knowing the shape of the outcome space keeps a deal from becoming a standoff over a few hundred dollars.
- Should I negotiate? Tool
Takes your result, your remaining days, and your leverage, and returns which of the standard resolutions your situation actually supports.
- Negotiating radon repairs Guide
How the conversation goes when both sides are reasonable, and where it stalls when one is not.
- Who pays Guide
What is customary, what is negotiable, and why custom varies by market rather than by law.
- Buyer credits vs mitigation Guide
The trade-off between cash at closing and completed work, including which one survives a lender.
- Negotiating Checklist
What to have in hand before the conversation, and what has to end up in writing.
- Home-Sale Radon Negotiation Outcome Taxonomy Dataset
The outcome categories themselves, defined so a conversation can name what it is aiming at.
- Home-Sale Negotiation Outcome Frequency Dataset Dataset
Read the methodology on this one first. It is a published instrument with no observations yet, and it says so.
- Should I negotiate? Tool
Timelines, lenders, and closing
Radon delays closings through paperwork and scheduling far more often than through the mitigation work itself.
- Closing delays caused by radon Guide
Where the days are actually lost, which is rarely where people expect.
- Inspection practice Newsroom
How inspection practice shapes whether radon comes up at all, and how that varies.
- Radon and market conditions Newsroom
Why the same result is negotiated differently depending on how much leverage the market is handing each side.
- Closing delays caused by radon Guide
Houses that already have a system
An existing system is an asset or a liability depending entirely on whether anyone can produce documentation for it.
- Selling with a system Guide
What to gather so the system reads as a feature rather than as evidence of a past problem.
- Buying a home with high radon Guide
Buying into a known elevated result deliberately, with the work priced into the deal.
- Selling a home with high radon Guide
Selling with a known result and disclosing it properly, which is a narrower obligation than most sellers assume.
- Selling with a system Guide
What you should be able to do afterwards
- Count backwards from your closing date and know which options still fit.
- Name the resolution you are negotiating toward instead of arguing about a number.
- Decide between a credit and completed work on grounds other than which sounds simpler.
- Assemble the documentation that makes an existing system an asset.
Related hubs
- Testing your home — A number is only as good as the conditions it was collected under.
- Costs and value — We explain what moves a price. We do not publish one we have not measured.
- State regulations — Almost nothing about radon is federal law. Nearly all of it is state practice.
- All nine hubs — the full learning centre.
Confidence and limits of this page
Every decision resource on this platform states its own boundaries. This is not a disclaimer — it is the part of this hub you should read before relying on it.
- What we knowClaims on this page we stand behind, each traceable to an approved source or to observable structure.
- Published buyer and seller guidance describes testing during a transaction and treats mitigation as negotiable between the parties rather than as a legal requirement.
- Disclosure obligations exist in some states and concern known results and required pamphlets; in Illinois the statute requires disclosure and does not require testing or mitigation.
- Contract deadlines rather than the measurement itself are what make radon urgent in a live deal.
- What we do not knowQuestions you may reasonably have that this page does not answer.
- How often each negotiated outcome actually occurs, in this market or nationally. We publish the outcome taxonomy and an empty instrument for the frequencies, because we have observed none.
- What any individual agent, lender, or counterparty will accept, which is local practice rather than rule.
- What research would settle itWhat it would actually take to answer the above — naming it is the difference between honesty and hedging.
- A body of recorded transaction outcomes with result, days remaining, and resolution, which is exactly the instrument we have published and not yet filled.
- Comparison of disclosure practice across states, which would need primary collection from filings rather than from statute text.
- What we do not claimClaims you might expect to find here and will not, with the reason.
- We do not claim what a given negotiation will cost or concede, because we hold no transaction observations and any figure would be invented.
- We do not give legal advice about disclosure, and nothing here substitutes for counsel licensed in your state.
- We do not claim any state requires testing or mitigation on a residential sale unless the statute says so and we have cited it.
- What we cannot independently verifyFacts this page relies on that we could not confirm ourselves.
- Local custom in your market on who pays, which varies by county and by year and is not published anywhere we could cite.
- The current content of the cited statutes and guidance, for the network reason stated in our methodology.
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Sources
- U.S. EPA — Home Buyer’s and Seller’s Guide to Radon
- Illinois General Assembly — Illinois Radon Awareness Act (420 ILCS 46)
- U.S. EPA — A Citizen’s Guide to Radon
- IEMA-OHS — Illinois Emergency Management Agency and Office of Homeland Security — Radon Program