Radon is the one hazard that can sit inside a house for years and nobody ever knows. It has no smell, no stain, no slow leak you can notice from the basement. The only way to find out is to test. And that is the problem in West Michigan: a house can be in excellent shape and still have an elevated radon level. Testing costs a fraction of what you spend on the rest of the purchase.
Why radon is a real West Michigan issue
Radon is a naturally occurring radioactive gas. It comes from the breakdown of uranium in soil and rock underground. In most of the country the level in a home is low enough to ignore. In Michigan it often is not. The EPA classifies most Michigan counties, including Kalamazoo and Allegan, in its highest radon-risk category, the areas where the estimated average home reading is above four picocuries per liter, the level the EPA calls its action level.
Two things make it worse here. The first is the geology: much of the region sits over fractured bedrock and glacial soil that lets soil gas move freely. The second is the season. West Michigan homes stay sealed tight for months of cold weather, with windows and doors shut and the furnace cycling. That trapped, recirculated air is exactly the condition that lets radon concentrate indoors.
How radon gets into a home in the first place
Most of the time it gets in through the foundation. A house sitting on the ground creates a slightly lower pressure than the soil around it, and the difference pulls soil gas up through whatever openings exist: cracks in a slab, gaps around pipes and floor drains, and especially sump pits. Crawl spaces work the same way, just with more direct access.
This matters for how you think about the rest of your purchase. A house that has had a sump pit sealed, a slab repaired, or a crawl space encapsulated may test better than it would have in its original condition. A tight, poorly ventilated house will test worse. The foundation work the seller has done over the years is relevant to what a radon test will show, and worth asking about while you still have a contract window to ask.
What a good test actually looks like
The details of the test matter as much as the number it produces. A few things a buyer should insist on:
- Test the lowest lived-in level. For a house with a basement, that is the basement.
- Keep the house in normal living conditions. Windows and exterior doors closed for at least 12 hours before the test and throughout it.
- Use a test long enough to be meaningful. Most buyers use a 48-hour or seven-day test. A two-hour test is not.
- Ask for a professional test, not just a kit, when you can. A certified tester knows where to place the device and how to read the result against the conditions of the day.
When the result comes back, the benchmark is the EPA action level of four picocuries per liter. At or above that, the EPA recommends mitigation. Between two and four, many buyers treat it as a conversation, not a walk-away. Under two is generally comfortable. These are guidelines, not rules, and a licensed radon professional can put a number in context.
What to ask the seller
Ask for the records before you order anything new, and keep the answers in writing:
- Has the house ever been tested for radon, and what did it show?
- When was the test run, under what conditions, and was it a short-term or long-term test?
- Is there a mitigation system in the house? Who installed it, when, and who maintains it?
- If there is a system, is it running now, and where does the vent pipe discharge?
- Are there any past high readings, retests, or repair work on record?
A house with a working mitigation system is not a problem house. It is a house where someone already found the problem and fixed it, which is more information than you get from a house that has never been tested. But a seller who claims the system is running and cannot produce any records is not giving you anything you can plan around.
What happens if the test comes back high
A high result is not the end of the deal. Radon is one of the more fixable problems a home can have. The standard correction is a mitigation system: a fan under the slab or in the crawl space that pulls the soil gas up and out through a vent pipe to the roof, so it disperses outside instead of inside. The install is usually a day or two of work and costs a few thousand dollars, which is nowhere near the scale of a structural problem.
The practical question is who pays, and that is a negotiation, not a law. In Michigan, a seller has no legal duty to install a mitigation system. What the seller does have to do, through the Seller's Disclosure Statement, is report what they know about the condition of the property, including known test results and the presence of a mitigation system. If the seller tested high and said nothing, that is a disclosure problem.
The way to handle a high reading is to get a written estimate from a certified mitigation contractor, then bring that estimate back to the table. The options are the same as any other inspection finding: the seller mitigates before closing and you retest, the seller gives you a credit, the price comes down, or, if the number is severe and the seller will not move, the inspection window is what it is for and you walk.
How to fit it into your contract window
Radon testing does not take long, but it does take conditions, and that is the part people plan around poorly. A 48-hour test that starts on a day when the house is open for showings, or the windows are cracked because it has been sitting in August heat, will not tell you much. If it has been empty and warm and open, the test will understate what a winter resident will see.
Build the test into the same window as your other inspections. The radon professional can often run it while the general inspector is on site, which keeps the cost down and the calendar simple. You want the result in hand while you still have days to respond.
The short version
Test the house you are buying, during the contract window, in normal winter-like conditions. Get the seller's records first, and verify with your own test when the house has never been tested or the last result is old or seasonal. If it comes back high, get a written estimate for mitigation and put it on the table. A high radon level is a known, fixable problem, and the cost to fix it is a small piece of the whole purchase. The risk is not the gas. The risk is the house that was never tested and the buyer who finds out after closing, when it is no longer a negotiation.
This article is general real estate information, not environmental, health, legal or lending advice. Radon risk varies house to house, and test results depend on the conditions at the time of testing. Confirm the details for a specific property with a certified radon professional, and talk to your doctor about the health implications of any result that concerns you.
If you are buying in Grandville, Grand Rapids or elsewhere in West Michigan and a radon test is on the list, call or text me at (616) 856-1492. I can help you line up a test during your contract window, review any records the seller has on hand, and make sure a high result gets priced into the deal instead of becoming a surprise after closing.
Rennie Barton
REALTOR® and broker/owner, City2Shore Arete Collection. Questions about this post? Call or text (616) 856-1492.