Between military moves to and from F.E. Warren Air Force Base, state government hires, and people relocating from the Front Range, Cheyenne sees a steady flow of buyers who don't know the area. Many come from Colorado, where radon testing in home sales is routine, and they expect it here too. This page explains how radon testing usually fits into a Wyoming home purchase or sale. It's general information, not legal advice; your contract and agent govern the details.
For buyers
Put radon in your inspection plan
If your offer includes an inspection contingency, schedule the radon test alongside the general home inspection so the results land inside the contingency period. A professional radon test typically runs at least 48 hours, and a pro needs time to set up, retrieve, and report. If your inspection window is tight, book the radon test the same day your offer is accepted.
What a transaction test looks like
Most real estate radon tests use a calibrated continuous radon monitor. It logs hourly readings and motion, and some models log temperature, humidity, and barometric pressure. That record helps show whether closed-house conditions were kept. The report usually arrives right when the test ends.
Closed-house conditions need cooperation
Windows and outside doors closed for 12 hours before and during the test, and no swamp cooler or whole-house fan. In an occupied home, the seller has to cooperate, and agents often have sellers sign a non-interference form. Testing during a major windstorm can complicate a short-term result; the professional should note the weather.
If it comes back at 4 pCi/L or higher
The usual paths, depending on your contract:
- Seller mitigates before closing and provides a post-mitigation test below 4 pCi/L.
- Credit or price reduction so you can choose the installer and pipe route yourself after closing.
- Walk away, if your contingency allows and the deal no longer makes sense.
Buyers who plan to finish a basement or care about how the exterior pipe looks often prefer a credit so they control the design.
If it's under 4 pCi/L
Good, but a two-day reading in August may differ from a winter average. Consider a long-term test during your first heating season.
Questions about a reading? A certified Cheyenne-area pro can help. (307) 317-5825
For sellers
Test before you list
A pre-listing test lets you deal with radon on your own schedule. If you're high, you can get quotes from more than one certified mitigator, choose a clean pipe route, and put the post-mitigation result in your listing packet. That's often smoother than negotiating under a buyer's deadline.
Already have a system?
Have the installation paperwork, post-mitigation test, and fan warranty ready. Make sure the manometer shows suction and the fan is running. Inspectors check.
Disclosure
Wyoming sellers typically complete a property disclosure as part of the sale, and known material issues should be addressed honestly. Ask your agent or a real estate attorney exactly what your contract requires regarding past radon tests or systems.
Who pays?
It's a negotiation, not a rule. Sellers commonly cover mitigation, either directly or through a credit, when a buyer's test is high, since the cost is modest compared with losing the sale. For scale, Angi's 2026 national data puts typical active radon systems at about $805 to $1,326, with complex homes costing more. That's a national benchmark only; quotes come from the professional who inspects the house.
Military buyers and renters
On-base housing at F.E. Warren is managed through the base housing office, so contact that office about radon in base housing. For off-base purchases with VA loans, follow your lender's and agent's guidance on inspections. Renters in Cheyenne should ask their landlord about testing; owners normally handle any mitigation.
Fitting mitigation into a closing
- Book a certified mitigator quickly, as soon as the result is in.
- Install the system.
- Wait at least 24 hours, then run the post-mitigation test.
- Share the result with the buyer before closing.
For impartiality, buyers can ask that the post-mitigation test be done by a different certified professional than the installer.
Questions about a reading? A certified Cheyenne-area pro can help. (307) 317-5825
How we fit in
Call or send the form with the property ZIP and your deadline. We'll connect you with an independent, certified radon professional who works in that part of Laramie County. You schedule and pay them directly.
Cheyenne housing and what it means for a sale test
The age and type of a house affects where the monitor goes and what a fix would likely involve:
- Older homes in the Avenues and near downtown may have stone, brick, or block basements, sometimes with partial dirt floors. A fix there may need membrane work as well as slab suction, which matters when you're sizing a credit.
- Mid-century ranches and split-levels often have poured basements or garden levels. They're usually straightforward to test in the lower level and to mitigate with a single suction point.
- Newer tight construction on the city's edges can trap radon. Some have a builder-installed passive pipe. Ask whether one exists and whether it was ever tested.
- Rural acreage homes on private wells may call for a water test as well as an air test.
Winter and wind during a test
Many Cheyenne sales happen during the heating season, when radon readings tend to be higher. That's not a flaw in the test. It reflects real winter conditions. If a strong wind event happens during a 48-hour test, the professional's notes and hourly data help explain unusual swings, and a retest may be reasonable.
Common questions from Cheyenne buyers and sellers
Can a test be done if the home is vacant?
Yes. Keep the heat on at normal settings and the house closed. A vacant home is often easier to keep in closed-house conditions.
Is the seller's earlier test acceptable?
Only if both sides agree. Many buyers prefer a fresh test from a certified professional they selected.
How soon after installation can we retest?
The post-mitigation test should start at least 24 hours after the fan is turned on.
Questions about a reading? A certified Cheyenne-area pro can help. (307) 317-5825