How much does radon mitigation cost in Northern Colorado?

State health figures put most homes in the $1,000 to $2,000 range, and Colorado retail pricing runs from $1,200 to $2,500 for a standard sub-slab system, with about $1,500 a common all-in figure. Crawl spaces cost more. The exact quote depends on your foundation, home size, radon level, and how the vent pipe has to route to the roofline. Get a fixed bid from a licensed professional who has seen the home.

Why is a crawl space more expensive to mitigate?

A crawl space usually needs a sealed vapor barrier across the soil plus a fan tied into the barrier, which is more material and labor than a slab. That tier commonly runs $2,000 to $5,000. Tight or inaccessible crawl spaces that need an air-exchange unit such as an HRV or ERV can run higher still, at a price that varies by installer.

My builder left a radon rough-in. What does activating it cost?

Many newer Northern Colorado homes ship with a passive radon-resistant pipe already run from the foundation to the roof. If a test comes back high, a licensed professional usually only adds an in-line fan and a monitor to make that passive stack active. That fan-only activation costs well below a full retail install, so ask the licensed professional for a fixed quote.

Is there help with the cost of radon mitigation in Colorado?

There may be. The Colorado Department of Public Health and Environment runs the CDPHE Low Income Radon Mitigation Assistance program, and households that qualify may be offered help toward a certified mitigation system. This site does not publish amounts or eligibility rules, because they change and CDPHE sets them. The current terms are on the agency's own page at cdphe.colorado.gov/hm/low-income-radon-mitigation-assistance. Budget against the price of the job itself, then treat any program as a possible offset.

Why do national radon prices look cheaper than Colorado quotes?

National averages, such as figures around $1,000, blend low-radon regions with high-radon ones. Northern Colorado sits in EPA Radon Zone 1, the highest-potential category, so local homes often test high and need robust systems. Treat national numbers as a floor, not a Colorado quote, and price against the Colorado retail band instead.

Radon Mitigation Cost in Colorado

Price is usually the first question after a radon test comes back high, and it is a fair one. Across Northern Colorado, meaning Larimer and Weld Counties, fixing a radon problem is a defined job with a fairly predictable cost, not an open-ended repair. NoCo Radon Pros is a free referral service, not a contractor, so the numbers below come from Colorado health agencies and Colorado installers, and the actual bid always comes from the independent, Colorado-licensed radon professional who sees the home.

A quick note on why this matters here specifically: both Larimer and Weld Counties fall in EPA Radon Zone 1, the category with the highest predicted indoor levels. Statewide, about half of Colorado homes exceed the EPA action level of 4.0 pCi/L. A high result on your own test is the trigger for everything on this page.

The honest cost band for a standard system

For a typical home with a slab foundation, the two most reliable sources land close together. Colorado public-health guidance, echoed by Larimer County citing CDPHE, puts most homes in the $1,000 to $2,000 range. Colorado retail pricing runs a little wider, roughly $1,200 to $2,500 for a standard sub-slab depressurization system, with about $1,500 a common all-in figure.

Put together, a fair expectation for most Northern Colorado homes is $1,000 to $2,500, with around $1,500 the number you will hear most often for a standard sub-slab install. Some Fort Collins installers advertise flat rates near the bottom of that band. If a quote lands far above $2,500 for a straightforward slab, ask what about your house is driving it, because the answer is usually one of the factors below.

It also helps to know what that price buys. A standard install typically includes the suction point cut into the slab, the sealed vent pipe run to the roofline, the continuous in-line fan, a visible pressure gauge (a manometer) so you can confirm the system is working, and sealing of obvious foundation cracks and the sump lid. A good bid spells out those parts. Ask whether a post-mitigation retest is included, since the only way to confirm the system actually pulled your level below 4.0 pCi/L is to test again after it runs.

A standard sub-slab system works by pulling radon-laden air from under the foundation through a sealed pipe and venting it above the roofline with a continuous fan. If you want to understand what the reading on your test even means before you weigh a bid, start with radon test results explained. For how the systems themselves work, see radon mitigation.

Crawl spaces and mixed foundations cost more

Homes with a crawl space, or a mix of slab and crawl space, sit in a higher tier. A crawl space usually needs a sealed vapor barrier laid across the exposed soil, with a fan drawing from beneath that barrier. That is more material and more labor than a bare slab, so the common range is $2,000 to $5,000 depending on the size and condition of the space.

Tight, low, or otherwise inaccessible crawl spaces are the outlier. When a barrier system is not practical, a professional may specify an air-exchange unit, a heat recovery ventilator (HRV) or energy recovery ventilator (ERV), which brings the crawl space toward the higher end, at a cost that varies by installer. If your home has a crawl space or a partial basement, the details on crawl space and basement radon explain what the licensed professional will be looking at.

Activating a builder’s passive rough-in

Here is the one situation where the cost drops sharply. Many newer homes across Northern Colorado, especially in fast-growing towns like Windsor, Timnath, and Johnstown, were built with a passive radon-resistant rough-in: a vent pipe already routed from the foundation up through the roof, with no fan.

If a test in one of these homes comes back high, the fix is often just making that passive stack active. A licensed professional adds an in-line fan and a monitor, at a cost that varies by installer. That is well below a full retail install because the hard part, running the pipe, was done during construction. If your home is newer, check for a labeled radon pipe in the basement or utility area before assuming a full system price.

What actually drives the price

Two homes on the same street can get different quotes for good reasons. The main factors:

Foundation type. Slab is the baseline. Crawl spaces, multiple foundation types under one roof, and finished basements all add labor.
Home size and layout. A larger footprint may need more than one suction point to depressurize the whole slab, which adds pipe and fan capacity.
Radon level. A very high starting reading can call for a stronger fan or additional suction points to pull the level down below 4.0 pCi/L.
System routing. Where the vent pipe can run to reach above the roofline matters. An easy interior chase through the garage is cheaper than an exterior run that has to climb the outside of the house and meet clearance rules.
Finishes and access. Concrete condition, sump presence, and how easy it is to reach the work area all move the number.

None of these are things you diagnose yourself. They are what the professional prices during the on-site quote.

Help with the cost in Colorado

Cost should not be the reason a high reading goes unaddressed. The Colorado Department of Public Health and Environment runs the CDPHE Low Income Radon Mitigation Assistance program, and households that qualify may be offered help toward a certified mitigation system. We do not list amounts or eligibility rules on this page. They change, and CDPHE sets them, so the agency’s program page is the one to read. Larimer County points residents to that same state program, and the wider state radon program is covered on the CDPHE radon FAQ.

Price the job on its own numbers first, using the bands above, then treat any program as a possible offset rather than as part of the budget. Ask the licensed professional what the current application asks for, since they handle these systems every week.

A word on national averages

You will see national figures, such as averages around $1,000, quoted online. Those numbers blend low-radon regions with high-radon ones, so they run lower than what Colorado homes typically cost. Because Northern Colorado is Zone 1 and local homes frequently test high, treat national averages as a floor rather than a quote. Price your project against the Colorado band on this page.

Where to go next

If your test came back at or above 4.0 pCi/L, that result is your green light to get bids. To see the bigger legal and geographic picture, including disclosure duties at sale and Northern Colorado’s Zone 1 standing, read the Colorado radon law guide. When you are ready for a fixed price, use our contact page and get a free radon quote from an independent, state-licensed professional near you. Curious how a free service pays for itself? Our how we make money page lays it out plainly.

To confirm any contractor’s standing, look them up on the Colorado DORA license lookup before you sign. Colorado licenses radon mitigation professionals; that license belongs to the contractor you hire, never to this referral service.