Radon and the Minnesota Home Sale: What Sellers in Woodbury and the East Metro Need to Know
What do Minnesota home sellers have to disclose about radon?
Under Minnesota Statute 144.496 (the Minnesota Radon Awareness Act), sellers must disclose in writing any known radon concentrations before signing a purchase agreement. The disclosure must cover whether any tests have been conducted, the most current test records and results, a description of any concentrations and mitigation or remediation work, and details about any mitigation system already installed. Sellers must also provide the buyer with a copy of the Minnesota Department of Health publication "Radon in Real Estate Transactions." Sellers who fail to disclose known radon levels face a two-year civil liability window starting at the closing date.
By Darin Bjerknes | May 28, 2026
Here is a scenario I see regularly in the east metro: a seller in Woodbury lists their home, receives an offer, the inspection period opens, and seven days later the buyer's inspector delivers a radon test result of 7.4 pCi/L. The sellers are caught off guard. They had not tested before listing, they had no idea their basement had elevated radon, and now they are in the middle of a negotiation they were not prepared for.
Radon is not a niche concern in Washington County. Suburbs like Woodbury routinely see test results in the 4.0 to 12.0 pCi/L range. The Minnesota Department of Health estimates that more than 40% of Minnesota homes exceed the EPA action level of 4.0 pCi/L, and the average indoor radon level across Minnesota is more than three times the national average of 1.3 pCi/L. Washington County itself offers free short-term radon test kits at four service center locations because the prevalence here is that high.
What sellers often do not know is that real legal obligations are attached to this number, and real consequences come with handling it wrong.
What Minnesota Law Actually Requires
Minnesota's Radon Awareness Act, Minnesota Statute 144.496, sets clear obligations for sellers of residential real property. Before a purchase agreement is signed, sellers must provide a written disclosure covering five items: (1) whether any radon tests have been conducted on the property, (2) the most current test records and reports including specific concentration levels detected, (3) a description of any radon concentrations and any mitigation or remediation work performed, (4) information about any mitigation system currently installed including a system description and documentation, and (5) a radon warning statement as defined by the statute.
Sellers must also provide the buyer with a copy of the MDH publication "Radon in Real Estate Transactions," which explains radon health risks and testing guidance.
One important nuance: Minnesota law does not require sellers to test for radon before listing. The disclosure obligation is triggered by knowledge. If you have never tested and have no knowledge of radon levels, you disclose that fact. If you have tested at any point and for any reason, you must disclose every result you have.
That distinction matters strategically. A seller who tests before listing and finds elevated radon can control the situation. A seller who tested two years ago, found high levels, and never mitigated has a disclosure obligation and a liability exposure that needs to be addressed before the listing goes live.
The Two-Year Seller Liability Window
Minnesota Statute 144.496, Subdivision 3 states that a buyer injured by a failure to disclose known radon concentrations may bring a civil action and recover damages. That liability window runs for two years from the closing date.
The liability is not automatic for sellers who simply did not know. It is triggered by knowledge. But in practice, if a seller tested the home three years ago, found elevated levels, and lists the home today without disclosing those results, they are exposed. Test records do not disappear, and disclosure forms are signed under penalty of law.
This is one area where a pre-listing conversation with your agent about your test history matters before anything else happens.
Why Nearly Every Buyer Will Test Your Home
Even if you disclose a clean or unknown radon status, assume the buyer will test during the inspection period. In the east metro, radon testing is now standard practice at most inspections. Major inspection companies include a radon test as part of their standard package or offer it as a low-cost add-on.
The standard short-term radon test runs 48 to 96 hours. The buyer places a closed-house test during the inspection window and receives results before the inspection contingency deadline.
When results come back at or above 4.0 pCi/L, buyers typically respond with one of three requests: the seller installs a mitigation system before closing with verified post-installation results below 4.0 pCi/L, the seller provides a closing credit ($800 to $2,000) for the buyer to mitigate after purchase, or the purchase price is reduced to reflect mitigation cost.
None of these outcomes are catastrophic. Each requires negotiation, and each is easier to manage when the seller has already thought through the scenario before day one on the market.
Three Seller Paths
Path 1: Test and Mitigate Before Listing
This is the strongest seller position. Test the home before the listing goes active. If the result is below 4.0 pCi/L, you disclose a clean test result and it becomes a selling point. If the result is elevated, you schedule mitigation immediately.
Radon mitigation in the Twin Cities typically costs $800 to $1,800 for a standard single-family home with a full basement. Homes with split-level layouts, slab additions, or separate crawlspace areas may run $1,500 to $2,500. The most common system used is active sub-slab depressurization: a licensed contractor installs a pipe and fan that draws radon-laden air from beneath the slab and vents it above the roofline.
Minnesota licenses radon mitigation contractors through the Department of Labor and Industry. Using a licensed contractor matters, both for insurance and for the post-mitigation test documentation that buyers and their agents will ask to see.
A seller who mitigates before listing can advertise the home with a working mitigation system and confirmed below-action-level results. For many buyers in the east metro, that is a premium feature, not a concern.
Path 2: Disclose Prior Test Results and Offer a Closing Credit
If you have tested before, you must disclose. If the prior result was above 4.0 pCi/L, the most common resolution is to disclose the results, let the buyer's inspector confirm current levels during the inspection period, and negotiate a closing credit to cover mitigation.
In a typical east metro transaction, sellers offer a $1,000 to $1,500 closing credit when the buyer's radon test comes back elevated. That amount covers a standard sub-slab depressurization installation and post-mitigation test.
There is a tradeoff. The buyer controls the vendor, the installation timing, and the system design. For sellers who want maximum control over the outcome, pre-listing mitigation produces a cleaner result.
Path 3: List Without Testing
This is legal to do if you have no prior test results. The disclosure form reflects "no prior tests conducted" and you meet your statutory obligation. The buyer will almost certainly test during the inspection period.
This is the least strategic path for sellers in high-radon areas. If the buyer's test comes back elevated, you are now negotiating from a reactive position during the inspection contingency window, without having had time to get your own contractor quotes or understand your options.
For sellers in Woodbury, Lake Elmo, Stillwater, or Afton, the probability that a buyer's test will come back above 4.0 pCi/L is significant. Testing before listing costs $15 to $30 for a short-term kit. Washington County offers free test kits at four locations: the Cottage Grove Service Center, the Forest Lake Service Center, the North Environmental Center, and the South Environmental Center. That information, gathered before listing, puts you in control of the conversation.
What Happens If the Buyer Tests During the Inspection Period
Radon testing most commonly happens during the inspection contingency period, after the purchase agreement is signed. The buyer's request for mitigation or a credit is handled through inspection contingency negotiation, not as a pre-closing statutory trigger.
Under the MNAR Inspection Contingency form, if the buyer identifies a material defect, they can request remediation or a price adjustment. A radon reading at or above 4.0 pCi/L qualifies as a material defect. If the parties cannot agree on a resolution, the current MNAR form language states that the purchase proceeds as written, meaning buyers who fail to address radon during the inspection window cannot automatically cancel on radon grounds once the contingency period closes.
For sellers, this means a radon-based inspection addendum is a cost negotiation, not a deal killer, as long as the response is reasonable and timely.
How the Luxury Segment Handles Radon
In Woodbury, Lake Elmo, Stillwater, and Afton, where median sale prices for move-up homes run $500,000 to $900,000 and above, a $1,200 radon credit does not derail a transaction. Buyers at this price point expect houses to have functional systems.
Where radon becomes a larger issue is when sellers do not know their numbers going in. An 11 pCi/L result on a $750,000 home in Lake Elmo sounds alarming. Without seller context, prior mitigation data, or a contractor quote already in hand, it rattles buyers who were on the fence.
A pre-listing test costing $15 to $30 removes that uncertainty entirely. If the number is low, it is an asset. If it is high, mitigation at $1,000 to $1,500 solves it before day one on the market. That is the kind of preparation that keeps a transaction on track when the inspection report lands.
FAQ
Is radon testing required before selling a home in Minnesota?
No. Minnesota law does not require sellers to test for radon before listing or before signing a purchase agreement. However, sellers who have previously tested must disclose all known results and radon concentrations under Minnesota Statute 144.496. Testing before listing is strongly recommended for sellers in high-radon areas like Washington County.
What is the radon action level in Minnesota?
The EPA and Minnesota Department of Health action level is 4.0 picocuries per liter (pCi/L). Levels at or above 4.0 pCi/L indicate that a mitigation system is recommended. This is the threshold buyers and their agents use in inspection period negotiations throughout the east metro.
What happens if the buyer's radon test comes back above 4.0 pCi/L during the inspection period?
The buyer typically requests one of three remedies: the seller installs and verifies a mitigation system before closing, the seller provides a closing credit ($800 to $2,000), or the parties negotiate a price reduction. Sellers are not obligated to any specific remedy, and the resolution is handled through the inspection contingency process under the MNAR form.
How long does radon mitigation take in Minnesota?
A standard sub-slab depressurization system takes one day to install. A licensed contractor drills a suction point in the slab, installs a pipe and fan venting above the roofline, and seals visible slab cracks. Post-mitigation testing begins 24 hours after installation and takes 48 to 96 hours to confirm that levels have dropped below 4.0 pCi/L.
Does a radon mitigation system affect a home's sale price or buyer appeal?
No, not negatively. A working mitigation system with confirmed below-action-level results is a positive feature. Many buyers in the east metro specifically prefer homes that have already been tested and mitigated because it eliminates uncertainty during the inspection period. Sellers who complete mitigation before listing enter negotiations in a stronger position than those who leave the issue for the buyer to resolve.How to Handle Radon as a Minnesota Seller: Five Steps
Step 1: Review your test history before listing
Before the listing goes active, determine whether any radon tests have ever been conducted on the property. Check prior home inspection reports, purchase documents, and any previous testing records. If a test was conducted, the results must be disclosed under Minnesota Statute 144.496.
Step 2: Test before listing if you have no results
Pick up a free short-term test kit from any of the four Washington County service center locations, or order an MDH-approved kit for $15 to $30. Place the kit in the lowest livable level of the home per MDH instructions for 48 to 96 hours. Results come back within a few business days.
Step 3: Schedule mitigation if results are at or above 4.0 pCi/L
Contact a Minnesota Department of Labor and Industry-licensed radon mitigation contractor for a quote. Standard quotes in the east metro run $800 to $1,500 for a typical single-family installation. Schedule the work before the listing goes active or be prepared to offer a documented closing credit.
Step 4: Complete the radon disclosure section of the Seller's Property Disclosure Statement
Before signing the purchase agreement, complete the radon sections of the Seller's Property Disclosure Statement. Attach test records and mitigation documentation. Provide the buyer with the MDH 'Radon in Real Estate Transactions' publication as required by Minnesota Statute 144.496.
Step 5: Respond clearly to buyer inspection-period test results
If the buyer tests during the inspection period and finds levels at or above 4.0 pCi/L, respond with a proposal anchored to contractor estimates: a closing credit for the documented mitigation cost or a pre-closing installation with verified post-mitigation results. Keep the conversation factual and cost-specific.
Thinking about listing your home in Woodbury, Lake Elmo, Stillwater, or anywhere else in the east metro? Radon is one of about a dozen disclosure items I walk every seller through before we hit the market. The prep conversation is free. Reach out at [email protected] or book a call at calendly.com/darintheminnesotan.
Contact a licensed Minnesota real estate attorney or title company for legal questions about your specific transaction.
Darin Bjerknes | Minnesōtan, Brokered by REAL | [email protected]
