Denver County · Front Range
Denver sits on the Front Range, where roughly half of Colorado homes test above the EPA action level of 4.0 pCi/L. Radon levels vary from one house to the next on the same street, so a test is the only way to know your home's number.
3 radon professionals listed · Updated November 2026
Serves Denver, Boulder, Aurora, Arvada, Littleton, Longmont, Golden, Englewood, Castle Rock
Radon and vapor-intrusion firm with a Littleton office that says it has served the Denver area since 1987.
NRPP-certified (per company site)
Serves Arvada, Denver Metro, Northern Colorado, Front Range
Arvada-based radon company with NRPP-certified mitigation and measurement staff and a 5-year transferable warranty.
NRPP-certified (per company site)
Serves Denver, Arvada, Broomfield, Centennial, Englewood, Golden, Lakewood, Littleton, Thornton, Westminster, Wheat Ridge
Denver-based, owner-operated radon mitigation company founded in 2015.
Certification not confirmed
Own a radon company in Denver? Add or claim your listing.
Much of Denver's housing has full or partial basements, from pre-war bungalows in Washington Park and Highlands to mid-century ranches in Harvey Park and the newer homes in Stapleton (Central Park) and Green Valley Ranch. Basements sit in direct contact with the soil, which is where radon enters a home.
Older homes often have cracked slabs, stone or block foundations and open sump pits that let soil gas in. Newer homes are built tighter for energy efficiency, which can hold radon indoors longer once it enters. Both kinds of homes can test high.
Most Denver systems are active sub-slab depressurization: a sealed pipe through the basement floor, a fan, and an exhaust above the roofline. A finished basement or a home with a crawlspace addition usually needs extra routing or a second suction point, which raises the price.
Most Denver homeowners pay $1,200 to $2,000 for a standard sub-slab depressurization system in a basement home. Finished basements, crawlspaces and homes with several foundation types can run $2,500 or more.
Colorado does not require a radon test to sell a home, but buyers commonly test during the inspection period, and many Denver mitigation jobs are scheduled during a sale. Ask the seller for any past test results.
A standard system is usually installed in one day. The contractor should run a follow-up test after the system has operated for at least 24 hours to confirm the level dropped below 4.0 pCi/L.
Colorado requires radon mitigation professionals to be licensed by the Department of Regulatory Agencies (DORA). Ask for the Colorado license number, look for NRPP or NRSB certification, get a written quote that includes a post-mitigation test, and ask about the fan warranty.
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