City test kits
The City of Fort Collins radon page lists discounted kits for city residents: short-term $6, long-term $20, at the Senior Center, 1200 Raintree Dr. Prices can change, so call Healthy Homes at 970-416-2832 or email healthyhomes@fortcollins.gov to confirm before you go.
The short-term kit runs 3 to 7 days, and the city warns "Short-term test kits are time sensitive," so start it soon after you buy it. If you live outside the city limits, the city points you to CDPHE. Larimer County's page says state kits are free for a limited time, while CDPHE's testing page calls them discounted, so check before you order or call 303-692-2000. Larimer County has offered free kits too; see the county page.
What the Fort Collins numbers say
- The city says "About half of all Fort Collins homes tested have radon at this level," meaning 4 pCi/L.
- Colorado's health department says radon is "responsible for approximately 500 lung cancer deaths annually in Colorado."
- A Larimer County presentation gives an "average of 6,900 existing homes in Fort Collins" of 7.1 pCi/L. The presentation is undated and doesn't state the year of the data.
Those describe tested homes, and they're not a forecast for your address. Colorado's notes on its own test records say levels can vary widely between neighboring homes. Your street, your subdivision and your neighbor's test don't settle it. Only a test on your house does.
The city's target level
EPA's action level is 4 pCi/L, and it says "Consider fixing between 2 and 4 pCi/L." The City of Fort Collins' page names 2 pCi/L as the target for mitigation. That's the city's stated goal, and no one can promise any particular result, so ask a contractor what the contract commits to. EPA's contract list includes this question: "A guarantee to reduce radon levels to 4 pCi/L or below?"
The 2006 passive system test
Does your Fort Collins home have a builder's pipe? A Larimer County presentation reports a test the City of Fort Collins ran in 2006 on 65 homes. With the vent cap on, the average was 8.0 pCi/L. With it off, 4.1 pCi/L, about 50% lower. The takeaway: a passive pipe helped, but the average still sat above 4, so a pipe doesn't replace a test. The passive systems guide has more, including CDPHE's figure of about $500 to add a fan.
Fort Collins is on an AARST list of places with the radon appendix in their building codes, current as of September 20, 2021. For what applies to your home today, ask Building Services.
Fan cost on Fort Collins Utilities
A fan runs continuously, so it's a steady line on your bill. These are calculated estimates using Fort Collins Utilities' 2026 standard time-of-day rates, with a blended rate of about 11.87¢ per kWh over 8,760 hours:
| Fan | kWh per year | Cost per year |
|---|---|---|
| 20 watts | 175 | About $21 |
| 71 watts | 622 | About $74 |
The cost guide shows the full math and what's left out. A 7.0% increase for 2027 was proposed as of this check. This isn't your bill, and your actual fan size is a question for the contractor. EPA also notes a system can "cause some loss of heated or air conditioned air."
Permits in the city
No city page reviewed for this site says whether adding a radon system to an existing home needs a permit. Call Building Services at 970-416-2740 (281 N. College Ave., BuildingServices@fortcollins.gov) before work begins. The city's general permit page says "Most construction projects require a permit," that new or replacement receptacles need one, and "Permit exempt does not mean code exempt." The permit process page adds: "Work without a permit may cause problems when selling a home".
If you rent out a home here
The city's page covers radon in rentals. Colorado law calls for written disclosure before a lease is signed, and the city notes "Landlords are not legally required to install a system." It also says the tenant's lease remedy "will not apply to leases that are one year or less." See the home sale guide for the state law.
What it costs here
No sourced Fort Collins price exists, so don't trust a chart that claims one. Colorado's agency figures are $1,000 to $2,000 and about $1,300 to $3,000 from CDPHE (both undated), and about $1,200 on average, $800 to $2,500 from a state report dated October 15, 2026. They conflict. Your contractor's written quote is what counts. The city's page also names the state's low-income assistance program; the cost guide covers how to apply.
What commonly goes wrong
- Not using the kit in time. The city's warning on short-term kits is worth heeding.
- Treating the 6,900-home average as your number. It's a group average. Test.
- Assuming a builder's pipe settled it. See the 2006 results above.
- Finishing a basement without a retest. "After you remodel, retest in the lowest lived-in area."
- Sealing and stopping. "EPA does not recommend the use of sealing alone to reduce radon."
Who this page isn't for
If your home is outside the city limits, the city's kit program isn't for you; see the Larimer County page or the Windsor and Severance page. If you haven't tested, start with a test and not a system. If your household may qualify for state help, apply to CDPHE directly.
Hiring
The hiring guide lists what to ask about the pipe route, the fan and the follow-up test.
Questions homeowners ask
Where do I buy a radon kit in Fort Collins?
The city's page says the Senior Center, 1200 Raintree Dr., for city residents. Call Healthy Homes to confirm. Stores also carry kits.
How much of Fort Collins has high radon?
The city says about half of homes tested reach 4 pCi/L. Tested homes aren't all homes, and no map tells you about your house.
Is there help paying for a system?
The city's page points to the state's low-income assistance program. Apply to CDPHE directly, and check current openings first.
What does a fan add on my Fort Collins bill?
About $21 to $74 a year in the examples above.
Is there a Fort Collins permit for a radon system?
The pages reviewed don't say. Ask Building Services at 970-416-2740.
How this site helps
LarimerRadon.com is a referral service, not part of the city: a request here goes to one independent local contractor, who quotes and does any work directly with you.
Sources
- City of Fort Collins, radon page (undated, © 2026), Building Permits, Building Permit Process, Utilities rates (2026).
- Larimer County, indoor air presentation (undated).
- CDPHE, testing page and FAQ (© 2026, undated); state radon dataset notes (undated).
- Colorado Department of Regulatory Agencies, radon report (Oct 15, 2026).
- EPA, Consumer's Guide to Radon Reduction and A Citizen's Guide to Radon.
- AARST, code adoption data (lists as of Sept 20, 2021).