7 Scary Things Found in Minnesota Home Inspections (and What They Cost)

The scariest thing in a Minnesota house usually isn’t a creaky basement or outdated appliances. It’s the stuff you can’t see or smell until the inspector finds it while you’re waiting to close. Here are seven of the scariest inspection findings we see, what they cost, and what to do about them in a deal.

Costs are as of my video above (October 2026).

First: city evaluations aren’t inspections

In Minnesota, the buyer usually orders the home inspection. That’s different from a city point-of-sale or truth-in-housing evaluation, which 16 Minnesota cities (mostly in the metro, including Minneapolis, Saint Paul and Bloomington) require from sellers. In Minneapolis, the seller needs that report before the home can be shown; Saint Paul’s is disclosure-only, flagging issues but mostly not forcing repairs. Those reports help, but they’re not a full inspection. Never skip your own. (See city selling rules.)

1. Radon

A radioactive gas from the ground that you can’t see, smell or taste. The Minnesota Department of Health says more than 2 in 5 Minnesota homes have levels that pose a significant health risk, and mine was one of them. In a sale, the test runs at least 48 hours on the lowest livable level. A mitigation system (a pipe and fan that pull gas from under the house) generally runs $1,500 to $3,000.

Sellers must disclose known test results and systems but don’t have to test or fix. Buyers: test, and if it’s high, negotiate the system or a credit. In my experience, radon rarely kills a deal. What hurts is the buyer who skipped the test and finds out after closing.

2. Moisture trapped behind stucco

Stucco homes built from the late ’80s through the mid-2000s had a long history of water getting behind the stucco and rotting the framing. The city of Woodbury tracked it: by 2011, about two of every three stucco homes that existed there in 1999 had failed and been repaired, which the city called the largest construction defect problem in local history. Leaky windows, missing flashing and badly flashed decks were the main culprits, and many repairs ran $150,000 or more.

You usually can’t see it from outside. The only real way to know is invasive moisture testing, with tiny holes drilled to probe behind the stucco. Whole-house testing from one major Twin Cities company starts around $845.

I once had clients on a $1.5 million home in North Oaks. My trusted inspector, a former builder of these homes, saw nothing alarming. The stucco test found high moisture behind many walls, and three repair quotes ran $175,000 to $300,000, each with an asterisk saying “could be more.” Make the purchase contingent on invasive testing, even if the seller already tested, and renegotiate or walk if the numbers are bad. Sellers: have your testing records ready.

3. The sewer line

In Minneapolis, the homeowner owns the sewer line all the way to the city main, including the connection under the street. In older neighborhoods these lines can be a century old, and tree roots love them. A crack or collapse can back sewage into the basement or yard.

A sewer scope (a camera run down the line) finds it. Minneapolis lists an average replacement cost of about $13,000, with recent projects from a little over $2,000 to about $62,000. Scope it during your inspection, get a plumber’s quote and negotiate with real numbers. Sellers: if the line was replaced or lined, keep the paperwork; it’s a selling point.

4. Vermiculite attic insulation

A loose, pebble-like insulation, usually gray-brown or silver-gold, poured between attic joists. According to the EPA, a mine in Libby, Montana, supplied more than 70% of U.S. vermiculite from 1919 to 1990, and its ore was contaminated with asbestos. A plant in northeast Minneapolis processed vermiculite, mostly from Libby, from 1938 to 1989, so a lot of it is in Minnesota attics.

The EPA says to assume it contains asbestos and don’t disturb it. Removal requires a licensed asbestos contractor, about $7,500 for an attic by one Minnesota energy nonprofit’s estimate, and a trust has reimbursed part of the cost for some homeowners (check whether it’s still taking claims). If it’s sealed and you won’t touch the attic, it can stay. If you plan to add insulation or finish the space, budget for removal and negotiate up front.

5. Ice dams

Ridges of ice at the roof edge that trap melting snow, so water backs up under the shingles and into the house. The Center for Energy and Environment says the real cause is warm air leaking into the attic and melting the snow, which refreezes at the cold edge. Look for stained or cracked ceilings, peeling paint, soaked insulation, big icicles and stained siding.

The fix usually isn’t a new roof. It’s air sealing and insulating the attic, estimated at about $3,000 to $6,500, with Minnesota attics insulated to around R-50. Ask about stains near exterior walls. Sellers: keep records if you fixed the attic.

6. A failing septic system

More than 600,000 Minnesota homes and businesses use septic systems, mostly in rural areas and lake country. Soggy spots or odors are warning signs, but only a licensed inspector can tell you. Minnesota requires every seller to disclose in writing how sewage is handled, and some counties go further. In Dakota County, a compliance inspection is required before sale (with exceptions for recently inspected systems), and a failing system must be upgraded within 10 months, with buyer and seller negotiating who pays. Costs vary widely with soil and system, so get a real quote. More in Minnesota homes with hidden costs.

7. Knob-and-tube wiring

Early wiring from about 1880 to the 1940s, visible in unfinished basements, attics or garages as single wires running through ceramic knobs and tubes. It has no ground, the insulation breaks down with age, and it was never meant to be buried under attic insulation. The bigger problem is insurance: when a Twin Cities inspection company surveyed 34 insurers in 2019, 21 flatly refused to cover it. Rewiring a house runs around $15,000 to $20,000 by one national estimate; get a licensed electrician’s quote.

Call your insurance agent before your inspection period ends. If you’re financing and can’t get coverage, your lender won’t let you close.

The bottom line

None of these mean a house is bad, or that Minnesota is a bad place to buy. Our homes can be older and our winters are real. The scariest thing is skipping the inspection. Test for radon, scope the sewer, test the stucco and call your insurance agent early, and most of these become a negotiation instead of a nightmare. For contract questions, talk with a real estate attorney or your agent. Also see 6 red flags in older homes.