If a radon test came back above 4 pCi/L, you have a real problem — but not the one you probably think. The house isn’t unsellable. The problem is time.
Why radon kills financed sales — and not cash ones
When a buyer uses an FHA or VA loan, the appraiser must certify the property meets HUD’s Minimum Property Standards. HUD 4000.1 §II.A.1 requires a “safe and sanitary” living environment. VA Pamphlet 26-7 Chapter 12 carries the same language.
Neither document names radon by statute — but a result above 4 pCi/L triggers a repair condition from the appraiser in practice, particularly in high-radon states like Tennessee and Minnesota.
A repair condition means:
- Mitigation system installed ($800–$2,500 for most homes)
- Post-mitigation retest — minimum 48 hours
- Result must read below 4 pCi/L before the lender releases funds
That cycle takes three to six weeks at minimum, longer in winter when contractors back up. If you’re already under contract with a financed buyer who orders a radon test, you’re looking at a delay that can break the deal — especially if the buyer has a rate lock expiring or their own sale contingency.
Cash buyers don’t use lenders. No appraiser, no repair condition, no retest cycle. The radon reading factors into the offer, and the close happens on schedule.
What mitigation actually costs
A sub-slab depressurization system — a PVC pipe running from beneath the foundation slab to outside the roofline with a small fan — is the standard fix. It works on over 99% of homes according to the EPA. Most homes retest below 2 pCi/L after installation.
Installed costs:
- Single-point system, accessible slab: $800–$1,200
- Multi-point or block foundation: $1,500–$2,500
- Crawl space with soil gas membrane: $2,000–$3,500
The fan runs continuously (electricity: roughly $5–$10/month) and lasts 7–10 years. A working system is a feature, not a red flag — buyers in high-radon areas see certified mitigation as proof the seller addressed it.
The discount happens when there’s no mitigation and the seller drops the price instead. Buyers and their agents routinely request $10,000–$20,000 off an unmitigated home, even when the fix costs $1,500. Don’t let that math work against you.
Disclosure: what each state requires
Tennessee: TCA § 66-5-202 requires disclosure of known material defects. A test result above 4 pCi/L that you know about must go on the disclosure form.
Minnesota: Minn. Stat. § 513.59 goes further — it explicitly mandates radon disclosure by statute, not just under the general “known defects” catch-all. The Minnesota Department of Health estimates about 40% of Minnesota homes test above the EPA’s action level. The legislature made disclosure statutory because the problem is that common.
Florida: FL § 689.261 covers known material defects. Florida radon levels are generally lower, but inland counties with limestone and phosphate deposits can run high. If you know, you must disclose.
Texas: TREC Form OP-H Section 5 and TX Property Code § 5.008 apply the same requirement. Texas averages are lower than the Upper Midwest, but the disclosure obligation is the same.
If you tested and the result was high, you disclose in every state we buy in. The question isn’t whether — it’s how to handle the sale after you do.
East Tennessee: some of the highest radon geology in the country
Not all radon is equal. Geography matters.
East Tennessee sits on the Chattanooga Shale formation — uranium-bearing black shale and karst limestone that drives some of the highest natural radon concentrations in the country. Knox County is EPA Radon Zone 1, the highest tier, projected average indoor radon above 4 pCi/L.
Knox County is not alone. Zone 1 counties in East Tennessee: Anderson, Blount, Claiborne, Campbell, Grainger, Hawkins, Jefferson, Sullivan, Union, Washington, and Hamblen. If your house is in any of these counties, a high radon reading is a realistic expectation, not a surprise.
Buyers and agents in East Tennessee know this. A tested-and-mitigated house is more sellable than one with no test record, because “we don’t know” is a harder negotiation than “we know and we fixed it.” We buy houses throughout East Tennessee — see our Knoxville page for how the process works in that market.
Minnesota: where disclosure is mandatory by statute
Minnesota has a different problem: mandatory disclosure under Minn. Stat. § 513.59 means every buyer is already asking the radon question before they schedule a showing.
The Twin Cities metro, the Iron Range, and river valley communities are the highest-concentration areas. In Burnsville, Woodbury, Edina, or Eden Prairie, an unmitigated home with a high radon reading goes into every showing with that fact on the disclosure form. Financed buyers make mitigation a contingency. Sellers who want to avoid that negotiation either mitigate before listing or sell to a buyer who won’t require a repair condition.
We buy houses throughout Minnesota as-is. See our Minnesota page for details on the process there.
Three paths — with the math on a $280,000 house
| Path | Timeline | Costs | Net proceeds (est.) |
|---|---|---|---|
| Mitigate, retest, list with agent | 90–120 days | $1,500 + 6% commission ($16,800) | ~$261,700 |
| Disclose, reduce price, list with agent | 60–90 days | 6% + $10k–$20k reduction | ~$243,200–$253,200 |
| Sell as-is to a cash buyer | 7–14 days | None | ~$238,000–$252,000 |
The mitigation-and-list path wins financially — if you have 90 days. The cash-buyer path and the price-reduction path land at similar numbers. Where cash wins is schedule and certainty: no repair condition to satisfy, no retest cycle, no buyer who walks when the short-term test comes back borderline.
What a cash sale looks like when radon is involved
Here’s what happens after you submit your address:
- We call within 24 hours. If you have a test result, share it — we work from the actual number.
- We factor the mitigation cost into the offer. A system costs $800–$2,500; the offer reflects that honestly.
- You pick the closing date — as short as 7 days, or longer if you need time to move.
- We close through a title company. No showings, no inspection repair cycle, no lender conditions.
We buy houses in Tennessee and Minnesota with elevated radon readings. The result changes the number — it doesn’t end the call.
When we are not the right answer
If the timeline allows it, mitigation and a conventional sale is the better financial outcome. The math on a $280,000 home shows roughly $9,000–$23,000 more in your pocket than a cash sale — if you have 90 days.
Use a licensed agent instead if:
- The house is otherwise in good condition
- You have 60+ days before your deadline
- Radon is the only known issue
- You can cover mitigation upfront ($800–$2,500)
A cash offer makes sense when the deadline is real — a foreclosure auction date, a job relocation that won’t wait, an estate that needs to close — or when radon is one of several condition problems that would make conventional financing difficult regardless. If you’re facing both radon and a foreclosure deadline, read about that situation specifically.
Straight answers
Does radon have to be fixed before I can sell?
No. There’s no law requiring mitigation before a sale in Tennessee, Minnesota, Florida, or Texas. You must disclose a known high result. The buyer decides what to do with it. Financed buyers make it a repair condition; cash buyers factor it into the offer.
How long does mitigation take?
Installation is one day. The required post-mitigation retest takes a minimum of 48 hours (short-term passive test). Most lenders accept the 48-hour test. Total cycle from hire to cleared result: 7–21 days depending on contractor availability and season.
What if I haven’t tested?
No test means no disclosure obligation for radon — but the buyer will test during the inspection period in East Tennessee and Minnesota. In Knox County and surrounding Zone 1 counties, assume they will. Price the possibility into your expectations, or test before listing so you control the conversation.
Does a mitigation system hurt resale value?
No. Homes with certified-working systems sell at market rate in high-radon areas. The discount applies to unmitigated homes with known high readings — typically the cost of mitigation plus a negotiation buffer. That’s recoverable once the system is in.
Get a cash offer on your address
Put the address in below. We’ll call within 24 hours with a number. No obligation to decide.
We buy houses in Tennessee, Minnesota, Florida, Texas, and nationwide — as-is, radon and all. Close in 7 to 14 days, or on a schedule that works for you. No commissions, no fees, no repairs required before closing.
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