Radon Mitigation Cost
2026 Radon Mitigation Cost in Fort Collins
A traditional residential radon mitigation system in Colorado commonly falls within the same general price range as many other moderate home repairs. CDPHE currently identifies approximately $1,300 to $3,000 as a typical range for an existing single-family home and about $500 to activate a usable passive system. Real project prices vary because foundation design matters more than living-area square footage.
Drennen reviewed its 2026 residential job records through July to create the planning ranges below. The most common straightforward sub-slab price in that sample was approximately $1,398.25, while passive-system activations commonly clustered near $654.50. Crawl spaces, mixed foundations, difficult routing, multiple suction zones, membrane work, and repairs to incomplete passive systems cost more.
These are planning ranges, not advertised fixed prices. A reliable proposal requires the test result, foundation type, access, route, electrical conditions, existing system details, and a review of the actual building.
Typical 2026 Drennen Planning Ranges
Activate an Existing Passive System
Often about $650 to $900 when the existing rough-in is complete, correctly routed, accessible, and suitable for activation. Corrections, electrical work, multiple stacks, inaccessible piping, or a failed passive design can increase the price.
Straightforward Sub-Slab System
Often about $1,300 to $1,700 for a simple slab or basement foundation with a practical exterior or garage route and no unusual foundation divisions.
Crawl-Space or Sub-Membrane System
Often about $2,000 to $3,000 when a substantial gas-retarder membrane, perimeter sealing, piers, penetrations, collection piping, and access work are required.
Mixed Slab and Crawl-Space System
Often about $2,200 to $4,000, depending on the number of foundation zones, membrane area, suction points, fan requirements, routing, and whether the zones can share one system.
Complex Residential System
Projects with large crawl spaces, multiple additions, inaccessible routes, low-permeability soil, several suction zones, interior routing, extensive repairs, or unusual construction can exceed $4,000 and may exceed $6,000.
Service, Fan, or System Repair
Common small service work may range from about $100 to $900. Fan replacement, alarm or electrical issues, membrane repairs, condensation, disconnected piping, and performance troubleshooting are priced according to the actual scope.
The ranges above reflect Drennen internal records and current Colorado public guidance available when this page was prepared. They are not a promise that a different property will fall within the same range. Review at least quarterly.
Why Two Similar Homes Can Have Very Different Prices
Foundation zones
A single open basement slab can be simpler than a home with a basement, slab-on-grade addition, crawl space, sunroom, garage transition, and isolated footings.
Crawl-space size and condition
Membrane area, height, debris, standing water, piers, utilities, foundation walls, access, and existing vapor barriers all affect labor and materials.
Route and fan location
An exterior route is often direct. An attic or garage route may look cleaner but can require more planning, firestopping, electrical coordination, roof work, and access.
Soil and pressure-field extension
A single suction point may communicate across the slab, or foundation walls and dense soils may require additional points or a different fan.
Existing passive system quality
Activation is inexpensive only when the buried collection, membrane, stack, labels, route, electrical provisions, and discharge are usable. Correcting a poorly built system can cost more than adding the fan.
Electrical work and monitoring
Fan power, disconnects, alarms, monitoring devices, and local electrical requirements must be addressed. The proposal should identify what is included.
Permits and local requirements
Permit and inspection requirements vary by jurisdiction and project type. A low quote may exclude work that later becomes an added cost.
Anonymized 2026 Drennen Examples
Passive-system activation
Multiple ordinary activations in Drennen records were priced near $654.50. This represents adding an active fan to a usable existing stack, not rebuilding an incomplete passive system.
Straightforward slab system
A common 2026 Drennen residential price was approximately $1,398.25. Several ordinary slab projects fell between roughly $1,234 and $1,650.
Full crawl-space system
One 2026 crawl-space project was approximately $2,465 and included sub-membrane work rather than only a fan and pipe.
Mixed foundation
Several mixed slab-and-crawl projects fell around the mid-$2,000s, while a highly complex project exceeded $6,000.
Fan and service work
Drennen service records include small no-charge warranty visits, modest troubleshooting, fan replacement, and more involved repairs. A service price cannot be estimated accurately without identifying the failure.
What a Complete Quote Should Identify
- The foundation areas included in the design
- The number and general location of suction points or collection zones
- Crawl-space membrane scope, material, seams, walls, piers, and penetrations
- Pipe route, fan location, discharge location, supports, labels, and monitoring
- Electrical work, permits, testing, cleanup, and documentation
- Whether an existing passive system is being accepted as-is or corrected
- Post-mitigation testing and the performance target
- Fan, workmanship, and performance warranty terms
- Clearly priced optional work and assumptions
How to Compare Radon Bids
Do not compare only the bottom line. Confirm that every contractor is using a currently active Colorado Radon Mitigation Professional, following the standards incorporated by Colorado, including the same foundation zones, using a comparable crawl-space membrane, providing the required monitoring, and including post-mitigation testing and a written warranty.
CDPHE recommends obtaining at least three bids from licensed professionals and asking for a guarantee that the system will reduce radon below 4.0 pCi/L and for at least a five-year fan and workmanship warranty. Drennen offers its own written warranty terms, which should be reviewed in the current proposal rather than assumed from website copy.
Frequently Asked Questions
Get a Written Radon Proposal
Send Drennen the property address, current radon result, foundation type, crawl-space information, existing system details, access contact, and any real estate deadline. We will identify whether a remote estimate is reasonable or an on-site evaluation is needed.
Request a Radon QuotePricing last reviewed July 2026. Material, labor, permit, electrical, and testing costs change. This page is educational and does not replace a written property-specific proposal.
Drennen Custom Contracting | Fort Collins, CO | 970-482-9100 | [email protected]