Radon Testing vs. Mitigation: Which One Does Your House Need?
Testing tells you the number. Mitigation lowers it. Every house starts with a test. Use this page to find your next step.
Find your situation
- Never tested? Start there. Run a short-term test on the lowest lived-in level. No one should quote you a mitigation system before a number exists.
- Result between 2.0 and 3.9 pCi/L? That is below the EPA action level. The EPA still suggests considering mitigation in this range. A long-term or winter retest gives you a better annual number before you decide.
- Result at 4.0 pCi/L or higher? Confirm with a second test. If the number is far above the line, or a closing date is near, get a mitigation quote now.
- Buying or selling? The transaction sets the protocol and the timeline. See radon in a Willmar home sale.
- Home built after mid-2009 and testing high? Minnesota code gave your house passive radon piping. Adding a fan to it is usually the cheapest fix available.
- Already have a system? Check the manometer gauge to confirm it is pulling. Retest every two years.
The two steps, side by side
| Testing | Mitigation | |
|---|---|---|
| What it does | Measures the radon level in your air | Lowers it by pulling soil gas from under the slab and venting it above the roof |
| Typical cost | Cheap. Hardware-store kits work. Real estate deals require licensed measurement. | $1,500 to $3,000 for a standard system, per MDH. Often under $1,000 to add a fan to passive piping. |
| Time | 2 to 7 days for a short test. 91+ days for a long-term test. | One day to install for most single-family homes |
| Who does it | You can test your own home. Paid testing requires an MDH license. | An MDH-licensed mitigation professional. Every system since 2019 carries a state tag. |
| Result | A number in pCi/L | A lower number, confirmed by a follow-up test |
Details on each: how testing works and how mitigation works.
Why you cannot skip the test
Radon has no smell, color, or taste. A test is the only way to know your level. Your neighbor's number tells you nothing. Levels change house to house on the same street. The number keeps working after you have it. It tells the installer how much reduction the system must deliver. It is the baseline the post-install test gets compared against. In a sale, it is the document the negotiation runs on.
Why airing out the house is not mitigation
Open windows lower radon only while they stay open. Minnesota houses are sealed for the seven-month heating season. That is when soil gas gets pulled in hardest and levels run highest. The fix that holds through a Willmar January is an active system with constant suction under the slab. A borderline summer test deserves a winter recheck for the same reason.
Not sure which step you are on? Describe the house and we will tell you. If the answer is to test first, we will say that.