Radon mitigation across the Twin Cities
The Twin Cities metro is one of the highest-radon major markets in the country, and Minnesota treats it that way: the state licenses radon professionals and requires sellers to disclose radon information before a purchase agreement is signed.
Housing here spans a century and a half — Minneapolis and St. Paul’s dense pre-war neighborhoods, postwar first-ring suburbs, and the vast newer growth across Dakota, Washington, and outer Hennepin counties. This hub routes three territories.
Radon in Minneapolis–St. Paul
EPA places the Twin Cities metro counties in Zone 1 of its Map of Radon Zones, its highest predicted category, and Minnesota’s health department reports that a large share of Minnesota homes test at or above the action level. Long heating seasons matter too: closed-house conditions concentrate radon for months at a time. Individual homes still test the full range, so your own measurement is what settles your number.
Who may do the work in Minnesota
Minnesota licenses radon measurement and mitigation professionals through the Minnesota Department of Health. This is a genuine state license rather than a voluntary credential, and it is what you should verify before hiring — ask for the license and confirm it is current and covers mitigation.
Radon in a Minnesota home sale
The Minnesota Radon Awareness Act requires sellers of residential property to disclose known radon information and provide the state’s radon publication to buyers before signing a purchase agreement. It does not require testing or mitigation — the response to an elevated result is negotiated, and a written quote from a licensed contractor is what makes that negotiation concrete.
Why results vary across Minneapolis–St. Paul
The metro sits on glacial till and outwash over a Paleozoic bedrock sequence that surfaces along the Mississippi gorge: Platteville limestone and St. Peter sandstone under Minneapolis and St. Paul, Prairie du Chien dolomite south and east through Dakota and Washington counties. That dolomite is karstic, and where glacial cover thins over it, soil gas moves toward foundations efficiently. Within the metro, the useful distinction for a homeowner is between the deep prewar city stock and the newer suburban ring — the two need very different work.
Housing stock and foundations here
This is one of the deepest prewar housing stocks in the upper Midwest: 1900s–1930s bungalows, Foursquares, and Tudors on block and limestone across south Minneapolis and much of St. Paul, on narrow lots with alleys — and those alleys frequently provide a discreet exterior routing option the street elevation does not. Deep frost lines mean full basements almost everywhere. An enormous postwar rambler belt fills Bloomington and Richfield; Eagan, Woodbury, and Maple Grove carry 1990s-forward poured basements.
Does new construction change the answer?
Minnesota adopted radon-resistant construction requirements in its residential code years ago, so a great many newer houses carry a capped stack from beneath the slab to the attic. Activating one is the least expensive legitimate path to a mitigated house here — and it still requires a post-mitigation test, because rough-in quality varies and some perform poorly once a fan is applied. Code-compliant construction is not the same as a verified low reading.
When to test in Minneapolis–St. Paul
Minnesota winters produce the strongest heating-season stack effect of any market on this platform, so closed-house readings from December through March are both easy to arrange and appropriately conservative — which is why the state program encourages heating-season testing. Frost depth affects exterior trenching, which most designs avoid. For a house you already own, a ninety-day alpha-track detector costs less than a professional short-term test and averages across weather.
Minneapolis–St. Paul guides
Five commercial guides written for this market — the work itself, what testing involves, what it costs here, what to do after an elevated result, and what installation day looks like.
- Radon Mitigation in Minneapolis–St. Paul
- Radon Testing in Minneapolis–St. Paul
- Radon Mitigation Cost in Minneapolis–St. Paul
- Failed Radon Test in Minneapolis–St. Paul
- Radon System Installation in Minneapolis–St. Paul
City guides in this market
Not sure whether your ZIP is covered? The quote form resolves it instantly and tells you honestly if it is outside our current territories. Browse all markets.
Deciding who to hire? The homeowner decision guides cover comparing bids, what drives cost, handling a result inside a transaction, and how to verify the work — starting with how to choose a radon contractor.
Licensed radon professional in Minnesota? See how Minnesota territories work — coverage requirements, homeowner qualification, and how to apply.
Minneapolis–St. Paul questions
What exactly does Minnesota require sellers to do?
Under the Radon Awareness Act, sellers must disclose known radon testing and results and provide the Minnesota Department of Health’s radon publication before a purchase agreement is signed. There is no requirement to test or to mitigate. Buyers routinely order their own test during inspection because seller disclosure only covers what the seller already knows.
Which communities does this market route?
Six published city guides across Hennepin, Ramsey, Dakota, and Washington counties, plus additional ZIPs including Hopkins, Minnetonka, Wayzata, St. Louis Park, Golden Valley, Roseville, Maplewood, Shoreview, Lakeville, Apple Valley, Burnsville, and Stillwater.
Does the long Minnesota winter change testing?
It makes winter testing especially meaningful. Closed-house conditions — windows shut, heating running — are exactly what short-term protocols require, and they describe how you actually live for a large share of the year here. A properly conducted winter result needs no asterisk and no summer re-run.
What exactly does the Minnesota Radon Awareness Act require of a seller?
It requires disclosure of what the seller knows about radon in the property — including any test results and any mitigation work — and delivery of the Minnesota Department of Health's radon publication before a purchase agreement is signed. It does not require the seller to test, and it does not require the seller to mitigate at any concentration.
How close can the discharge be to my neighbour's house on a narrow lot?
It has to clear your eave and stand away from windows, doors, and other openings into occupied space — and on a narrow city lot that includes your neighbour's openings, not only yours. This is a real constraint in south Minneapolis and St. Paul, where houses sit close together. Walk the discharge location with the contractor before installation.
The seller disclosed a past elevated test but never mitigated. What now?
That disclosure is exactly what the Act is designed to produce, and it puts you in a good position: you know the house has read high and you can test it yourself during your inspection period. Get a current measurement and a written mitigation quote, then negotiate from both. A disclosed history plus a verified fix is a cleaner outcome than a house nobody ever measured.
Sources
- U.S. EPA — Radon
- U.S. EPA — A Citizen’s Guide to Radon
- U.S. EPA — Consumer’s Guide to Radon Reduction
- U.S. EPA — EPA Map of Radon Zones
Quotes across Minneapolis–St. Paul
One request, routed by ZIP to independent licensed radon mitigation contractors covering this market.