What radon mitigation costs in the Denver metro
Denver metro pricing depends heavily on what is under your main floor. A conventional basement slab, a crawlspace, and a structural floor over a void are three different jobs, and a quote that does not name yours is not a quote for your house.
The largest western market on this platform, with high transaction volume, a broad price range, and a housing stock that spans a century of very different building responses to the same difficult soils. Contractor density is high, so three or four certified bids are realistic and the spread among them is informative.
What drives the price locally
Conventional sub-slab work on a poured basement with an accessible sump is the market’s low end. Sub-membrane work in a crawlspace or structural-floor void adds material and labor — sealing a membrane properly across an irregular soil surface takes time. Houses with both a basement and a crawlspace are two zones. Add HOA-driven interior routing in the southern suburbs and sealing on prewar Denver foundations. With contractor density this high, three certified bids give you a real benchmark. Expansive soils shaped local building practice in ways that matter directly for radon. Structural floors over a void space — a suspended floor with a crawl area beneath, rather than a slab poured on grade — are common in the southern suburbs where claystone heave is severe. That void is a soil-contact zone with its own mitigation approach, and it is not something a standard sub-slab design addresses.
Reading and comparing quotes
Read quotes side by side on what they actually contain: how many suction points, where each one goes, how far the pipe travels and through what, which fan by make and model, what sealing is included, whether a manometer is fitted, who pulls electrical, what the warranty covers and for how long, and whether a post-mitigation verification test is priced in. In the Denver metro the cheapest number on the page is often the one missing two of those lines. Confirm a current NRPP or NRSB mitigation certification before comparing anything else. Structural-floor voids and crawlspaces change the design and the price, because sub-membrane depressurization or void depressurization is different work from coring a slab. Add suction point count where arkosic sands or claystone under a slab behave inconsistently, HOA-driven interior routing, sealing on prewar foundations, and zone count where a house has both a basement and a crawlspace.
How cost shows up in a transaction
Colorado requires sellers of residential real property to give buyers a radon warning statement and the state’s radon brochure before a sale, and the standard seller’s property disclosure addresses radon testing and mitigation. Colorado does not require a seller to test or to mitigate — the response to an elevated result is negotiated like any other inspection finding.
Communities we route in Denver Metro
Radon Mitigation Cost questions in Denver Metro
Is sub-membrane work in a crawlspace more expensive than a basement system?
Usually, because the material and the labor are greater — a membrane has to be sealed across the whole soil surface, up the perimeter walls, and around every pier and penetration, often in a space with limited headroom. The offsetting benefit is performance: a well-sealed membrane gives the fan a large uniform area to draw from, and these systems frequently perform very well.
Why do two quotes in the Denver metro differ for the same house?
Denver holds a deep prewar stock of brick bungalows and Denver Squares on the near-north and near-east sides, many with garden-level basements or crawlspaces. Lakewood, Arvada, Aurora, and Littleton carry an enormous postwar ranch and split-level belt. Highlands Ranch and the southern suburbs are 1980s-forward construction, much of it built to deal with expansive claystone.
Will you tell me a price before a contractor sees the house?
No, and be careful with anyone who does. A firm number in the Denver metro depends on the foundation type, how many soil-contact zones the house has, where the pipe can legally and practically run, and what the sub-slab material will actually do. Quotes are free and come from the contractors themselves, so you get real numbers rather than an average.
Related Denver Metro guides
- Radon mitigation in Denver Metro
- Radon testing in Denver Metro
- Failed a radon test in Denver Metro
- System installation in Denver Metro
- Colorado radon contractors: join our network
Decision guides for this stage
- What drives mitigation cost
- Comparing contractors and bids
- When the cheapest bid costs more
- All homeowner decision guides
Price is the last question, not the first. Confirm the reading, get the design in writing, then compare numbers across Denver & Jefferson, Arapahoe & Douglas, and Adams & Broomfield. Requests are free, there is no obligation, and no more than three independent contractors ever receive one.
Sources
- U.S. EPA — Radon
- U.S. EPA — A Citizen’s Guide to Radon
- U.S. EPA — Consumer’s Guide to Radon Reduction
- U.S. EPA — EPA Map of Radon Zones
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