How much does radon mitigation cost in Northern Colorado?

For most homes, a standard active sub-slab system runs $1,000 to $2,500, with about $1,500 common. Crawlspace work costs more because it usually adds a sealed vapor barrier, often $2,000 to $5,000, and harder cases can run higher. The licensed pro you are matched with gives you a firm quote after seeing your foundation, so treat these as planning ranges rather than a promise.

How long does a radon system take to install?

A standard sub-slab depressurization system in a typical home is often a one-day job. The licensed professional cores the slab, runs the vent pipe, mounts the fan, and seals major entry points in a single visit. Complex foundations, multiple sub-slab suction points, or crawlspace vapor barriers can add time, and a confirmation test follows a couple of days later.

What radon level means I need mitigation?

The EPA action level is 4.0 pCi/L. At or above that number, the EPA advises fixing the home. Between 2.0 and 4.0 pCi/L you may still consider action. Since Larimer and Weld counties sit in EPA Radon Zone 1, a test is the only way to know your specific reading before deciding on a system.

Does NoCo Radon Pros install the system?

No. We are a free matching service, not a contractor, and we never hold a Colorado radon license. We connect you with an independent, state-licensed radon professional who does the diagnostic, design, install, and post-mitigation test. You can confirm any pro's license on the state DORA lookup before work begins.

Will a system actually lower my radon?

A properly designed active sub-slab depressurization system routinely brings elevated readings well below 4.0 pCi/L, which is why the licensed pro runs a post-mitigation test to confirm the result. If the first reading is not low enough, the system can usually be adjusted, for example by adding a suction point or upsizing the fan.

Radon Mitigation in Northern Colorado

Elevated radon does not fix itself, and in Northern Colorado the odds of finding it are high enough that mitigation is a common home project rather than a rare one. Larimer and Weld counties both sit in EPA Radon Zone 1, the highest-potential category, and about half of Colorado homes exceed the action level statewide. If a test comes back at or above 4.0 pCi/L, the next step is a system that actually pulls the gas out from under your house. NoCo Radon Pros is a free matching service. We do not install anything and we never hold a Colorado radon license. What we do is connect you with an independent, Colorado-licensed radon professional who handles the work start to finish.

Why mitigation matters here

Radon is a soil gas that seeps up through the ground and collects inside homes. It is the second leading cause of lung cancer in the United States after smoking, and the leading cause among people who have never smoked. The soil chemistry across the Front Range is exactly the kind that produces it, which is why the whole region reads as Zone 1 on the EPA radon map. Geology does not tell you your number, though. Two houses on the same street can test very differently, so testing is always the first move. Once you have a result at or above the EPA action level of 4.0 pCi/L, mitigation is the fix.

How a licensed professional lowers radon

The standard method is active sub-slab depressurization, sometimes shortened to ASD. The idea is straightforward. A licensed pro cores a hole through the concrete slab, runs a sealed PVC vent pipe from beneath the floor up and out above the roofline, and installs an inline fan that runs continuously. The fan creates a small suction zone under the slab so that soil gas is pulled into the pipe and discharged safely above the house instead of drifting up into your living space. A visible pressure gauge, called a manometer, lets you confirm at a glance that the fan is doing its job.

This is not a filter or an air purifier. It changes the pressure relationship between the soil and the house so the radon never gets inside in the first place. Done correctly, it is quiet, low-maintenance, and reliable for years, with the fan being the main part that eventually needs replacement.

Variants by foundation

Not every house takes the same system, and matching the design to the foundation is where a licensed pro earns their keep.

Slab-on-grade and full basements: usually a single sub-slab suction point, sometimes two if the sub-slab material does not let air move freely under the floor.
Crawlspaces: these need a different approach. The pro typically lays a sealed vapor barrier across the crawlspace floor and draws suction from beneath it, a method called sub-membrane depressurization. There is more detail on this in our guide to crawl space and basement radon.
Mixed foundations: many Northern Colorado homes combine a basement with a crawlspace or an addition on its own slab. These can require more than one suction point tied into a single system.
Passive builder rough-ins: newer homes in places like Timnath, Windsor, and Fort Collins were often built with an empty vent pipe already in the wall. If a test comes back high, activating that rough-in can be as simple as adding a fan.

What the licensed pro does, start to finish

A professional installation is a sequence, not a single act. Here is what the Colorado-licensed radon professional you are matched with typically walks through.

Diagnostic and site visit. The pro inspects your foundation, looks at how the slab was poured, checks for a sump, and identifies the best place to draw suction. This step is what determines the system design.
System design. Based on the diagnostic, the pro decides the number and location of suction points, the pipe routing, and the fan size. Bigger or leakier sub-slab areas need more airflow.
Installation. The pro cores the slab, runs and seals the pipe, mounts the fan, and seals major radon entry points such as slab cracks, the sump lid, and gaps around pipes. This is where sealing belongs, as part of the system, not as a standalone fix.
Post-mitigation test. After the system has run for a set period, the pro conducts a confirmation test to verify the reading is now below 4.0 pCi/L. If it is not, the system gets adjusted.

That post-mitigation test is the part homeowners sometimes skip when they try to shortcut the process, and it is the whole point. A system that is installed but never confirmed is a guess.

Typical timeline

For a standard home, a sub-slab system is often a one-day install. The pro arrives, cores the slab, runs the pipe, mounts the fan, and seals entry points, usually within several hours. The confirmation test happens afterward and takes a couple of days to run, so from install to confirmed result you are typically looking at a few days total, not weeks. Crawlspace systems with a full vapor barrier, or homes needing multiple suction points, take longer.

Cost ranges

Costs depend on your foundation, the number of suction points, and how the pipe has to be routed, but honest planning numbers help. For most homes, a standard active sub-slab system runs $1,000 to $2,500, with about $1,500 common. Crawlspaces cost more because of the sealed vapor barrier and can land in the $2,000 to $5,000 range, with difficult or inaccessible crawlspaces running higher. Activating an existing passive builder rough-in, where it is just a matter of adding a fan, is usually the cheapest path.

Colorado also runs a low-income mitigation assistance program that can cover a certified system, and some utility customers in the Larimer County area may qualify for a small rebate. Our radon mitigation cost guide for Colorado breaks the numbers down further. The quote from the licensed pro after their site visit is the figure that actually counts.

The licensing trust move

Here is the part worth slowing down for. Since July 1, 2022, Colorado has required a state license to perform radon measurement or mitigation for pay. The rule comes from House Bill 21-1195, and licensing is handled by the state Division of Professions and Occupations. Doing radon work for hire without that license is prohibited.

NoCo Radon Pros does not hold that license, because we do not do the work. The license belongs to the independent professional we match you with. You do not have to take anyone’s word for it, either. You can verify any radon pro’s active license yourself on the state DORA license lookup before a single hole is drilled. That is a simple, concrete way to protect yourself, and it is the reason we always point you to the state roster rather than to any single company.

Ready to get matched

If your test came back at or above 4.0 pCi/L, or you are buying, selling, or renting a home and radon has come up in the transaction, the next step is a licensed pro who can design the right system for your foundation. We connect you with independent, state-licensed local radon mitigation contractors serving Fort Collins, Loveland, Greeley, Windsor, and the rest of Northern Colorado at no cost to you.

Learn how the matching works on our about page, see the full list of services we can match you with, or head straight to contact to start. You can also read how we keep the service free on our how we make money page. For the legal side of high radon in a sale or lease, the Colorado radon law guide covers what disclosure actually requires.