Radon Mitigation System Cost: Average Prices & Cost Factors

Radon is a naturally occurring radioactive gas that can enter a home from the soil beneath it. A mitigation system draws that gas from under the foundation and vents it outside, usually with a pipe and a fan. The most common design is sub-slab depressurization, and a certified contractor typically installs it in a day or less.

This page covers what the system costs to install and keep running. For health guidance, testing steps, and the national action level, see the EPA radon page. Prices come from published sources with a check date of Oct 11, 2026.

The EPA recommends fixing a home when a long-term test shows radon at or above its action level of 4 picocuries per liter, and suggests considering action for results between 2 and 4. It links long-term exposure to a higher risk of lung cancer. The EPA also advises that homes be tested, since radon cannot be seen or smelled. Details and test guidance are on the EPA radon page. For questions about your own risk, contact your state radon office or a medical professional.

A standard professional system includes the pipe, fan, sealing of major openings, and a gauge that shows the system is working. Crawl space homes may need an extra membrane, listed in the table as encapsulation. A gas-tight sump pit cover is a modest add-on when the home has a sump.

DIY sealing and fan kits are listed as well. Sealing cracks alone is generally not enough to bring radon down, so treat it as a supplement to a fan-based system rather than a replacement. A DIY fan kit exists, but the work involves electrical connections, roof or wall penetrations, and proper venting. Many state programs recommend hiring a certified or licensed professional. Check your state radon office for licensing requirements.

New homes built with radon-resistant features have a passive pipe in place. If a test shows high levels, adding a fan can convert it to an active system, which is often cheaper than starting from scratch.

The fan runs around the clock, so it uses electricity continuously. Radon fans are designed for low power draw, but the exact monthly cost depends on the model and your local electric rate. The sources used here do not list a monthly figure, so none is given. The installer can tell you the wattage of the fan, and you can multiply it by your utility rate to estimate the monthly cost.

Fans do wear out. Replacement is listed in the table above. Check the system gauge regularly, and retest the home periodically, as the EPA recommends, to confirm that levels remain low.

State health departments and private companies publish somewhat different ranges. Local labor rates, foundation type, and what the quote includes may account for the gap.

• Foundation type. Slab, basement, and crawl space homes need different designs.
• Soil and gas flow. Soil that does not allow air to move easily can require a larger fan or multiple suction points.
• Home size and layout. Several foundation sections may need separate suction points.
• Pipe routing. Running the pipe through the house is different from running it up the outside wall.
• Electrical work. The fan needs power, and a new outlet or run may add cost.
• Sealing and extras. Sump covers, crawl space liners, and visible finishing work.
• Local licensing and permits. Requirements vary by state and municipality.

Look for a contractor certified or licensed through your state, or one listed by a national proficiency program. Ask for references and a written scope. The contractor should run a post-installation test, and some offer a performance guarantee for a set period. Avoid quotes that promise a specific result without testing first.

• Are you licensed or certified in this state?
• What system design do you recommend, and why?
• Does the price include a post-installation test, the gauge, and permits?
• Is there a guarantee if radon levels stay high?
• Where will the pipe and fan be placed, and how will they look?

A contractor should test the home after the system runs, and the EPA recommends retesting at regular intervals. Keep the manual, note the gauge reading when the system is working normally, and call the installer if the reading changes. Do not seal or block the vent pipe, and keep records for future buyers.