How much does a radon mitigation system cost?

Where does the $1,200 radon mitigation figure come from?

The $1,200 average that headlines most radon cost articles traces to A Physician's Guide to Radon, an EPA document whose web page now lives on archive.epa.gov and was last updated July 30, 2018. That page puts the average cost to correct a radon problem at about $1,200, ranging from about $500 to about $2,500. The archive host is where EPA parks content it no longer maintains, and the guide itself predates the 2018 stamp, so the most-quoted number in this market is, at minimum, eight years stale.

EPA today declines to name a price. Its current page, titled "How much can a radon mitigation system cost?", contains no dollar figure anywhere. It says most homes can be fixed for about the same cost as other common home repairs, that the cost varies with the size and design of your home and the reduction methods needed, and that the estimate worth having comes from one or more qualified mitigation contractors, not from a website. The Citizen's Guide to Radon says the same thing in more words: the cost to fix can vary widely, so consult your state radon office or get estimates from qualified mitigators.

Two national figures are still published, and they disagree in an instructive direction. Kansas State University's National Radon Program Services, which operates under a cooperative agreement with EPA, puts the national average at $1,200 with $800 to $1,500 common depending on house and market conditions; its page carries no date. HomeAdvisor's commercial cost survey, updated June 2026, lands lower: a $1,028 average, with most homeowners spending between $786 and $1,274.

The newest published number is the lowest, and the oldest number is the one everyone repeats.

What is a contractor pricing when they walk your house?

EPA's Consumer's Guide to Radon Reduction lists four inputs to the choice and cost of a reduction method: how high your initial radon level is, the costs of installation and operation, your home size, and your foundation type. Of the four, foundation type does most of the sorting, because it decides which system the house can physically take.

EPA categorizes homes by foundation design: basement, slab-on-grade, meaning concrete poured at ground level, or crawlspace, a shallow unfinished space under the first floor. Basement and slab homes generally get sub-slab depressurization, the pipe-and-fan system that pulls radon-carrying soil gas from beneath the slab before it enters the living space; the engineering and effectiveness of that system are covered on our radon mitigation method page and are not re-argued here. A crawlspace calls for a different technique EPA names submembrane suction: the earth floor is covered with high-density plastic sheeting, and a vent pipe and fan draw the radon from under the sheet, which EPA calls the most effective approach for crawlspace homes when properly applied. Many houses mix foundations, a basement under part of the home with slab or crawlspace under the rest, and EPA says a combination of techniques may then be needed to get below 4 pCi/L, picocuries of radon per liter of air, the agency's action level. More techniques on one house means more bid.

Here is what nobody publishes: a dollar figure for how much more a crawlspace or a mixed foundation costs. Every government and institutional source we verified describes foundation type as a cost driver in words and prices none of it, and the foundation-tiered price lists circulating online with EPA's name attached do not appear in any EPA document we could check. Treat those as marketing.

One discount is documented. EPA's Citizen's Guide states the cost is much less if a passive system, the fanless vent pipe some builders rough in during construction, was installed when the home was built. If your house has one, the job starts from a pipe already in the walls, so ask the contractor to look before pricing a from-scratch install.

Test before you price, and retest after the fan starts

A radon test kit costs under $25 by EPA's Basic Radon Facts factsheet, which makes measuring the cheapest step in fixing a radon problem and the only one that can say whether your house has a problem to fix. Radon offers no smell and no symptom to price against, so the measurement is not a formality. It is the only thing standing between you and paying to remove a problem the house may not have. No mitigation quote means anything until a confirmed reading at or above 4 pCi/L says the work is needed, and our radon testing guide covers kit choice, placement and the confirmation protocol.

Once a confirmed number puts you in the market, get two or three written estimates from licensed mitigation professionals, and let your state radon program supply the list of who counts as licensed. Stasis measures homes and interprets the results, and we neither install nor sell mitigation systems. When a result calls for a mitigator we refer you to one, referral arrangements pay us a disclosed 10 to 20 percent fee, and the audit fee covers the visit itself, so a finding earns us nothing on its own. The bids you gather are yours to compare.

The second measurement is the one people skip. After installation, retest. A mitigation system's success is a radon reading, not an invoice, and the post-installation verification protocol, when to start it and what number counts as success, lives on our radon mitigation method page. You bought a radon level, and only a measurement shows you received it.

Common questions

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