Cost of Radon Mitigation System Colorado: Pricing Guide
Colorado sits in the highest-risk EPA radon zone, and the cost of radon mitigation system Colorado homeowners face reflects both the high demand and the specific foundation types common across the Front Range. A typical Denver metro, Boulder corridor, or El Paso County mitigation installation runs $1,000 to $2,500 in 2026 dollars for a standard sub-slab depressurization (SSD) system. The variation within that range — and the cases where costs run higher — is driven by foundation type, basement layout, crawlspace presence, and exhaust routing. This guide breaks down what Front Range homeowners actually pay, what’s included, and what drives the cost up or down. The information here reflects NRPP standards, CDPHE program guidance, and EPA radon mitigation standards current as of 2026 and is informational only.
The Typical Front Range Mitigation Cost
For a standard single-family home in Denver, Douglas, Arapahoe, Boulder, Jefferson, El Paso, Adams, or Broomfield counties with a basement and a permanent forced-air HVAC system, a sub-slab depressurization mitigation system in 2026 typically falls in the $1,200 to $2,000 range. Homes at the lower end have:
Single-story full basement with poured-concrete walls. Standard 1,500-2,500 square foot footprint.
Open mechanical room location for the fan and pipe. No need to route around finished space.
Standard exhaust pathway. Pipe runs up an exterior wall or through a utility chase to a fan above the roofline.
Easy slab penetration point. Near the sump pit or in an unfinished section of the basement floor.
Homes at the upper end of the standard range — or pushing into the $2,500+ category — have one or more complicating factors: finished basement requiring careful pipe routing, crawlspace requiring vapor barrier installation, slab-on-grade requiring exterior pipe routing, multiple foundation depressurization points needed, or aesthetic constraints requiring interior pipe routing instead of exterior.
What’s Included in a Standard System
A reasonable Colorado mitigation quote at the $1,500 mid-point typically includes:
System design. The contractor’s pre-installation site assessment, communication test under the slab (if applicable), and system design specific to the home’s foundation.
Slab penetration. Coring a 4-5 inch hole through the basement floor, excavation of a sub-slab pit (typically 5 gallons of soil removed below the slab to create the suction pit).
PVC pipe. Typically 3-4 inch diameter schedule 40 PVC, running from the sub-slab pit through the interior of the home, up through the framing, and exiting above the roofline.
Inline radon fan. A continuous-duty fan rated for radon-mitigation service, installed above the highest occupied living level (typically in the attic or on the exterior). Common manufacturers include RadonAway, Festa, Tjernlund, and Fantech. Fan service life is typically 5-10 years.
System monitor. A simple U-tube manometer or digital pressure gauge that confirms the fan is producing suction. Installed in a visible location near the pipe.
Sealing of slab cracks and openings. Sealing of visible cracks, sump pit covers, and slab penetrations to maximize the depressurization effect.
Post-installation radon test. A 48-hour confirmation test 24-48 hours after the system is operating, to verify the result is below 4 pCi/L.
Permit fees, if required by the local building department. Most Front Range jurisdictions require a permit for radon mitigation, typically $50-$200.
System warranty. NRPP-certified contractors typically warranty their work for 1-5 years on installation, with the fan manufacturer warranty separately covering the fan itself.
Factors That Drive Cost Up
Several home-specific factors can push a mitigation system above the standard range:
Slab-on-grade foundation. Slab-on-grade homes — common in El Paso County and some Douglas County subdivisions — have less interior pipe routing flexibility and often require exterior pipe routing. The exterior pipe must be insulated to prevent condensation freezing in winter. Add $200-$500 for exterior routing and insulation.
Crawlspace foundation. Crawlspaces require a sub-membrane depressurization (SMD) system rather than SSD. A 6-mil or 10-mil polyethylene vapor barrier is sealed over the soil floor, the pipe penetrates the membrane, and the fan pulls soil gas out from beneath the barrier. Add $300-$800 for the membrane installation.
Mixed foundation (combination of basement and crawlspace, or two foundations from an addition). Multiple depressurization points may be required, each adding $300-$600.
Finished basement. Pipe routing through a finished basement requires careful planning to minimize visible pipe and patch any drywall openings. Add $200-$500.
Aesthetic interior routing. Routing pipe through interior chases and out the roof instead of the typical exterior wall path. Add $300-$700.
High-radon initial readings. Homes testing at 20+ pCi/L may need a larger fan, multiple suction points, or supplemental sealing to achieve the post-mitigation target. Add $200-$500.
Tight building envelope. Some newer homes have very tight envelopes that complicate the pressure balance, occasionally requiring make-up air provisions. Add $200-$500.
The radon system inspection guide covers what to verify on a newly installed or existing system, regardless of cost tier.
Factors That Drive Cost Down
Homes that fall at the lower end of the Front Range range typically have:
Open unfinished basement with easy pipe-routing pathway from the slab to an exterior wall.
Existing sump pit that can serve as the suction point with minimal slab work.
Single-story footprint with shorter pipe runs from slab to roof.
Standard exterior exhaust pathway against a side or rear wall where the pipe and fan are visually acceptable.
Lower initial radon level (4-8 pCi/L) not requiring oversized fans or multiple suction points.
For a single-story Front Range ranch with an unfinished basement and a sump pit, mitigation can sometimes come in at $1,000-$1,200.
Operating Cost After Installation
The mitigation fan runs continuously. The annual operating cost in Colorado is:
Electricity: $5-$15 per month depending on fan size and local electricity rates. Annual electricity cost typically $60-$180.
Heat loss through the pipe. The fan exhausts conditioned indoor air, which has a heating-season cost. Most properly sealed systems minimize this by pulling primarily from below the slab rather than from the basement air. Estimated annual heating cost increase $30-$100.
Fan replacement. Every 5-10 years, the fan motor wears out and needs replacement. Replacement fan cost typically $400-$700 including labor.
Total annual operating cost is roughly $100-$300 depending on home size, fan rating, and local energy prices.
Comparing Colorado Pricing to National Averages
National averages for radon mitigation typically run $800-$1,500 per the EPA’s published cost guidance, which can make Colorado’s $1,000-$2,500 range look high at first glance. The Front Range premium reflects three local realities. First, Colorado is an EPA Zone 1 high-risk state and the highest-radon counties in the country sit along the Front Range, which means contractors are routinely encountering 10-30 pCi/L baseline levels that require larger fans and tighter sealing than national averages assume. Second, Front Range housing stock skews toward full basements and finished basements with HVAC systems running below grade, which adds pipe-routing complexity compared to slab-on-grade southern markets. Third, Colorado’s permit and inspection regimes vary by county — Boulder, Denver, Jefferson, and Douglas counties typically require pulled permits for residential mitigation work, while some rural counties do not, and the per-permit cost varies $50-$200.
Out-of-state quotes are not directly comparable because national contractors quoting Colorado work without on-site assessment usually omit slab-on-grade complications, crawlspace membrane requirements, or interior routing constraints common in finished basements. A bid from a non-Colorado contractor that comes in at $800 typically reflects standard slab-and-attic routing assumptions that don’t match the actual home.
Financing and Insurance Considerations
Most Colorado mitigation contractors require payment in full at completion or 50% deposit plus balance at completion. Some offer 6-12 month financing through third-party home-improvement lenders, which can be useful for higher-cost installations. Mitigation costs are not typically covered by homeowner’s insurance because radon is classified as a maintenance/health issue rather than a covered peril.
In a real estate transaction, mitigation costs are commonly negotiated as a seller credit or escrow holdback when an inspection-period radon test returns above 4 pCi/L. The standard Colorado practice is for the seller to either install mitigation before closing (using an NRPP-certified contractor) or to credit the buyer at closing for the contracted mitigation amount with the buyer arranging post-close installation. The Colorado Association of Realtors radon disclosure addendum, required since 2009, formalizes this negotiation framework.
How to Get an Accurate Quote
For a meaningful mitigation cost estimate in Colorado, three steps:
Confirm the radon level with a second test. EPA recommends confirming any initial elevated result before contracting. A second short-term or one long-term test confirms the level and provides design information for the contractor.
Get bids from three NRPP-certified Colorado contractors. The NRPP and NRSB online directories list certified mitigation specialists by ZIP code. Most contractors offer free in-home quotes that include site assessment and system design.
Compare scope, not just price. The bids should include slab penetration, sub-slab pit, PVC pipe routing description, fan brand and model, sealing of cracks and sump pit, post-installation radon test, permit handling, and warranty terms. A $900 bid that omits the post-installation test or skips slab sealing isn’t comparable to a $1,800 bid that includes everything.
For first-time mitigation customers, the Colorado Radon Program at CDPHE maintains educational resources and a list of certified contractors. Some Colorado counties (notably Boulder and El Paso) periodically offer reduced-cost or subsidized mitigation through nonprofit programs for income-qualified homeowners. For the broader question of how the mitigation pricing fits into the radon testing arc, see the radon testing guide for Front Range homeowners.
References
- EPA Consumer’s Guide to Radon Reduction — U.S. Environmental Protection Agency
- CDPHE Colorado radon mitigation program — Colorado Department of Public Health and Environment
- InterNACHI radon mitigation overview — International Association of Certified Home Inspectors
- American Lung Association radon mitigation information — American Lung Association
Front Range homeowners ready to get mitigation quotes after an elevated radon test can reach our team through the contact page for a referral to NRPP-certified Colorado mitigation contractors.
Radon mitigation fans & parts
If a sub-slab depressurization system is the fix, the inline fan is the heart of it. Match the fan to your soil and pipe diameter — or have a certified installer size it.
| Product | Why | Buy |
|---|---|---|
 RadonAway RP145 Inline Fan | Common 4-in. SSD workhorse fan. | Amazon — $152.00 |
 Fantech Rn2 Radon Fan | Quiet operation; energy-efficient. | Amazon — $148.29 |
 Radon U-Tube Manometer | Confirms the system is pulling suction. | Amazon — $10.99 |