How Much Does a Radon Mitigation System Cost in St. Louis? [2026 Data]

The average radon mitigation system cost in St. Louis is $716, but it commonly ranges from $660 to $790. The factors that influence your overall cost include the mitigation method, the size and age of your house, and whether you need any additional work (like foundation repairs). Based on these factors, here’s how much you can expect to pay for radon reduction in St. Louis.

Radon Mitigation Cost Factors 

Here’s what to expect in terms of price when installing a radon mitigation system in St. Louis, MO.

Cost by Method

The cost of a radon mitigation system depends on the chosen approach, which might be sealing the basement, depressurization, or lower-level pressurization. The depressurization method happens in one of two types: active suction (soil depressurization) or passive depressurization. 

Here’s what to expect for pricing by radon mitigation method:

Cost by Home Size 

If you have a larger home, prepare to pay more for radon mitigation. To reduce radon in a bigger property, your pro may need to use extra materials and spend more time setting up the system, which can add $347 to $1,042 to your project costs.

Cost by Home Age

Your home’s age is another cost factor for this project. Over time, a house’s foundation can crack, making it more likely for radon to leak in. In cases like these, there may be additional costs for the extra equipment, materials, or labor needed for repairs.

Radon Mitigation Pro Costs

The cost of radon mitigation also depends on which permits you need and how much your contractor charges for labor.

Permits

Permits can also increase the cost of installing a radon mitigation system in St. Louis. Permit requirements depend on your specific project, but in many cases, you’ll need at least an electrical permit for the system’s electrical components. A radon detection and reduction specialist in St. Louis, MO, can let you know how much these permits cost and pull the right ones for your project.

Labor

Labor is another big expense when installing a radon mitigation system in St. Louis. These costs vary by contractor, but you should find your pro’s rates listed in your project estimate.

Licensing and Certification

Even though Missouri doesn’t have a licensing requirement for radon mitigation contractors, the state’s Department of Health and Senior Services (MDHSS) advises residents to hire a pro who’s certified by the National Radon Safety Board (NRSB) or National Radon Proficiency Program (NRPP).

Additional Pros to Consider Hiring

Sometimes, radon reduction will require multiple pros to handle different aspects of the project. Aside from a radon mitigation contractor, you might also need: 

• Electrical work: An electrician can add wiring, replace a radon fan, or handle other electrical work. For straightforward jobs like these, St. Louis electricians charge between $148 and $466. 

• Foundation repair: A solid, damage-free foundation can prevent radon from coming into your home. If yours needs fixing, the average cost of foundation repair in St. Louis ranges from $1,079 to $6,470.

• Encapsulation: Sealing your crawl space—also called encapsulation—is another common part of the radon mitigation process. Encapsulation costs vary but run between $2 and $10 per square foot.

Does a Radon Mitigation System Increase Home Value?

According to data from the MDHSS, one in three homes tested in Missouri has radon levels that exceed 4 pCi/L (picocuries per liter), the “action level” set by the Environmental Protection Agency (EPA). By adding a radon mitigation system to your St. Louis home, you’ll get the peace of mind of knowing that your family is protected against this dangerous gas. In addition, you could see a lift in your home’s value, since radon reduction systems are an attractive feature for homebuyers.

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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