Radon Mitigation: The Homeowner’s Cost Guide

Kenneth Wilson

One in 15 homes across the country (around 6% on a national level) has elevated indoor radon levels. Why should this be a matter of concern, you ask? A dangerous radon level– an invisible, odorless gas may cause lung cancer in the long run.

According to the Environmental Protection Agency (EPA), radon is considered the second primary cause of lung cancer in the United States (after smoking), with approximately 21,000 related deaths per year. If you have recently tested your home for radon only to find dangerously high levels, there's no need to sound the alarm yet.

Advancements in technology paved the way to successfully reduce radon levels in your home, commercial buildings, and schools. Thanks to radon mitigation systems, any elevated house can now be fixed by a professional radon contractor.

What is a Radon Mitigation System?

First, let's discuss what radon is all about. This radioactive natural gas is emitted from the ground. If radon is trapped indoors, such as after entering the inside of your homes through basement floors, foundations, and other openings– it may accumulate to dangerous levels. Frequent exposure to high radon levels is notoriously said to cause lung cancer. Accordingly, a radon mitigation system is designed to minimize the current radon concentrations in the indoor air of a house or a building.

The tricky thing is, you can't see or smell radon. The only way to know your home's current level of exposure is through testing, as it may negatively affect your indoor air quality. If your home's indoor radon level is higher than four pCi/L, the EPA urges you to act on the matter as soon as possible. When radon decays, it may get trapped in your lungs as you breathe.

Radon Mitigation Cost Overview

So, how much does a radon mitigation system cost? The national average for a professional contractor to reduce radon levels in a home is approximately $1,620. A more general estimate falls between $1,080 and $2,700. Remember that the total radon mitigation system cost heavily depends on your home's design, size, and other influential factors like the particular radon mitigation method.

Although, you can count on your radon mitigation cost to be on par with other home improvement projects– such as painting new walls or installing a new water heater.

Factors Affecting Radon Mitigation Cost

The average cost of radon mitigation varies from one home to another. Keep in mind that the total costs for your home may vary from the national average based on your home foundation type, size and design, geographic location, local labor costs, permit fees, and the method of radon system for your needs.

Let's discuss some other important cost factors that you need to consider:

Home Size and Design

Expect larger homes and houses with complex, intricate layouts to go beyond the national average cost of installing a radon mitigation system. Projects of this scale will need more materials as well as time. If your house only has a basement, the radon mitigation cost will be less than you would typically pay for a home with additional crawl space. Crawl spaces also require specific airtight vapor barriers to prevent radon entry effectively.

The flat rate may cost you up to $4,050, which typically includes the labor. However, it's best to consult your radon mitigation professional to ensure you're both on the same page.

Foundation Type

Determining the ideal radon reduction system for your home will depend on its foundation design. Radon removal will cost you an average of $1,620. Generally, there are three primary types of foundation: below-grade slab or basement, crawl space, and on-grade slab. Each of these types comes with a different radon mitigation approach.

For the below-grade slab or basement, your contractor will typically need a sump pump hole or do some drilling to insert PVC pipes underneath the slab. Meanwhile, a crawl space will use an encapsulation technique with a PVC pipe– which sticks out from the plastic membrane base. Due to its tricky accessibility, crawl space radon mitigation will take longer than other methods. Lastly, on-grade slabs insert PVC pipes from the house's exterior sides. In some cases, your contractor may drill a hole through the floor.

Other homes may have several foundation types, such as an underneath basement combined with a slab-on-grade or crawlspace. Accordingly, you will need to combine a few radon reduction methods to minimize your radon levels lower than four pCi/L. Keep in mind that this may cost you more than the national average radon mitigation cost.

Construction Materials

Your contractor uses different materials to help prevent radon entry into your home. Typically, any possible entry points need sealing, along with adding a vent pipe (passive system) or a fan (active system).

A passive radon system counts on the natural upward airflow to transfer radon through the pipes. Meanwhile, an active radon system is considered the ideal choice. It is better at radon removal as moisture and soil vapors are decreased. Other materials that may hike up the total cost to install a radon mitigation system include an electrical junction box, clean aggregate, sealing materials, or an oil-gas retarder.

You may benefit from installing radon-resistant features such as gravel and plastic sheets below the foundation and adequately sealing any cracks or gaps for a newly-built home.

Local Climate

Depending on the local climate your property is located in, your contractor will typically advise multiple options to reduce radon gas in your home. For households with a crawl space, you will typically benefit more from additional ventilation– such as installing a fan. However, those who live in cold climate areas will need to provide extra insulation to their sewer lines and water pipes as protection against the harsh cold.

Accordingly, this may hike up your monthly energy bills. Radon gets worse in the colder months, with radon levels historically found to be higher around this period. Radon gas also accumulates in enclosed areas quickly.

Operating Costs

In calculating how much it costs to mitigate radon, you will also need to consider the operating costs. It includes electricity to run the fan, comparable to running a 60 or 90 watt light bulb around the clock.

You will also need to cover some additional costs for potential heating and cooling needs, given that a significant percentage of air will be drawn outside your home by the newly minted radon system.

Labor and Permits

Most estimates already include the cost of labor mitigation itself. However, large-scale contractors with more expertise may charge you more. While you may save some money if you choose a contractor with low-skill labor, you may be at risk of getting the work quality compromised.

In some areas, you may also need to secure local radon mitigation-related permits. It will cost you around $34 to $202 on average. Extra electrical work will also require an inspection as well as permits. It would be best to prepare your budget accordingly.

Active system vs. Passive system

As previously mentioned, your radon mitigation system is either built as an active or passive system. An active radon mitigation system proves to be a better choice. Going with this route requires you to have the same passive system features– such as a vent pipe from the foundation to the roofing and sealing joints and gaps.

Additionally, you will need to install a fan, a monitor device, and an electrical outlet close to the radon pipe. A radon fan will cost you approximately $405 to $810, with a manufacturer warranty for 3 to 5 years. It is plugged into the electrical junction box to pull radon gas from under the house for outdoor emission.      

Radon Testing and Inspection

Testing and inspecting radon levels are crucial factors in keeping your home safe. Several radon-detecting smart devices and testing kits will cost you anywhere from $20 to $337– if you're planning to do it yourself, that is. Meanwhile, professional radon testing costs anywhere between $202 and $1,080.

Although DIY testing is an attractive choice if you want to save money, note that several kits may give you questionable results. If you want to ensure the safety of your house occupants from the dangers of radon gas, opt for a professional test instead. Here's a quick overview of the different radon testing methods:

  • Home radon test - These short-term test kits are left exposed in an open area under your home for approximately 2 to 4 days. After mailing the test, you will get the results after 72 hours through email.
  • Radon detectors - Smart detectors help determine the current radon gas levels inside your house. Note that these devices need a consistent power source to check air samples around the clock. Once radon levels go beyond the standard 4 pCi/L, these detectors will send you an alarm.
  • Professional test or inspection - Hiring a radon mitigation expert will help you determine the exact level of radon gases in your home. In selecting a contractor, it is ideal to look for associations with the American Association of Radon Scientists and Technologists (AARST) and the National Radon Proficiency Program (NRPP).
  • Water test kit - Any water source surrounding your home puts you at risk of radon exposure, although it is considered a lesser threat than air contamination. It will cost you about $63 to $270.

Keep in mind that expert radon mitigators and inspectors are not similar. Inspectors are tasked to determine and test radon levels, while mitigators are trained to install the system at home.

System Type

There are two primary radon mitigation system types: depressurization and lower-level pressurization.

  • Depressurization - A sub-slab system is the most common radon mitigation system type, which runs from $1,080 to $3,375.This system has various subtypes which use the fan to reduce radon levels by creating a vacuum underneath. Usually, PVC pipes are installed under the house's foundation or crawl space. The fan runs around the clock. It creates suction to push the radon gases away from the interior of your home.
  • Lower-level pressurization - Most basement and lower-level pressurization systems are priced between $675 to $1,350.This system seals all lower levels of a house to blow air inside. It also works with the vacuum to prevent radon gas from entering the home through the foundation. Generally, this choice is the most ideal for air-tight homes.


Given that radon can become a severe threat in your home, it would be best to purchase an extended warranty or a service plan to ensure safety.

If your radon mitigation system malfunctions, a professional contractor can fix the problem for you to reduce current radon levels to the EPA standards.

Common Radon Reduction Methods

There are different types of radon mitigation systems to reduce the radon levels in your home effectively. Each method has its unique advantages, and some may be more suitable than other choices for specific climate types.

To help you determine the best radon reduction method for your situation, let's discuss the most common system types and their average prices:

Radon Mitigation System Type

Average Costs

Interior Active Soil Depressurization

$1,350 - $4,050

Exterior Active Soil Depressurization

$2,025 - $4,000

Active Sub-Slab Soil Depressurization

$1,080 - $3,375

Crawl Space Sub-Membrane Depressurization

$1,080 - $4,050

Radon Fan or Pump

$135 - $405

Drain Tile Suction

$1,080 - $2,300

Sealed Sump Pump Hole System

$1,080 - $3,400

Block Suction

$2,025 - $4,050

Passive Soil Suction

$675 - $3,400

  • Interior Active Soil Depressurization: This is the most common radon mitigation system type. Interior active soil depressurization does not install pipes on the home's exterior– but it works just effectively. The average cost of this radon mitigation system will set you back around $1,350 to $4,050.The pipes are installed in the home's interior, usually from the closets to the upward vents (where the fan is installed). This system type helps maintain your property's curb appeal while making sure radon gas is eliminated efficiently.
  • Exterior Active Soil Depressurization: Like how the interior radon mitigation system works, exterior active soil depressurization installs the pipes outside the home instead. It runs for around $2,025 to $4,000 on average. The pipes are generally installed on the house's foundation, with a fan on the ground floor to push radon out of the basement. Homeowners who dislike the idea of having interior pipes opt for this system as a choice. It is also an excellent choice for houses with complex layouts, where you cannot install standard internal systems.
  • Active Sub-Slab Soil Depressurization: Active sub-slab depressurization systems get rid of radon gas under the home's foundation with a vacuum. The cost to install this radon mitigation system is between $1,080 and $3,375.Generally, PVC pipes are installed below the house (foundation or crawl space) that extends to the roof. A radon fan runs around the clock to ensure any radon gas is removed.
  • Crawl Space Sub-Membrane Depressurization: Crawl space sub-membrane depressurization is designed to decrease the internal air pressure, given how it's one of the leading causes of radon gas leakage inside the home. The radon mitigation cost for this system ranges from $1,080 to $4,050.A plastic vapor barrier is used to block radon entry through the soil in the crawl space. The pressure underneath is reduced with a fan that draws and pushes air upward the pipes.
  • Radon Fan or Pump: Depending on their size and strength, standard radon fans will cost you anywhere between $135 and $405. In some cases, it may even run a bit more. Most exterior radon fans are installed at the home's ground level, with interior fans in the attic or ceiling area. Additional features include a U-tube manometer or a suction monitor, priced at an extra $13 to $27.Your residential radon fan is expected to operate continuously, adding $40 to $405 more to your annual energy bills. Of course, this will depend on the cost of electricity in your locality.
  • Drain Tile Suction: A drain-tile radon mitigation system will cost you around $1,080 to $2,300 on average. This method uses drain tiles surrounding the home to make suction beneath the foundation. If your house has a slab foundation, common in areas with drainage problems or high water tables, you are likely to install drain tiles. These tiles around the slab make for a perfect suction location. The total cost of radon mitigation for this system will heavily depend on its placement, as these can be internal, under the slab, or surrounding the exterior.
  • Sealed Sump Pump Hole System: Most sealed sump pump hole systems cost around $1,080 to $3,400– if you use the existing sump pump hole, that is. The crock is to be completely sealed, so the vacuum stays in place beneath the foundation. Generally, this radon mitigation system is connected to the drain tile. Note that a drain tile is not a requirement for a sump pump hole system, though. The combination of a mitigation system and a sump pump installation will run for an additional $945 to $2,700.
  • Block Suction: A block wall suction method will cost you approximately $2,025 and $4,050. This radon mitigation system makes use of cinder blocks to make suction within the blocks' walls. For your reference, this method is more expensive than others but far less effective than general sub-slab systems.
  • Passive Soil Suction: Like how an active depressurization works, this radon mitigation method operates the same way minus the fan. It uses natural ventilation and the rise of warm air inside the house to reduce the radon gas accordingly. This system will cost you anywhere from $675 to $3,400.

Generally, a PVC pipe operates beneath the slab or crawl space and vents out in the roof. However, if your home has high radon levels, a passive depressurization system may not be an ideal choice.

Key Elements to Radon Mitigation

Radon mitigation processes are challenging and tricky. With that in mind, it should be handled by a trained professional to ensure your safety and efficient results. In selecting a contractor, choose a state or nationally qualified experts who can operate according to the local standards. Ideally, they must be in the guidance of the state license or certification and national proficiency program they are certified in.

There are three primary standards use by most states or proficiency programs to provide helpful guidance:

  • US EPA, 1994, Radon Mitigation Standards
  • ASTM Standard Practice for Installing Radon Mitigation Systems in Low-Rise Residential Buildings E2121
  • AARST, 2006, ASD Radon Mitigation Standards (June 2006)

Note that some states such as Florida, Illinois, and Pennsylvania have their unique local radon mitigation standards.

Simple Tips to Reduce Radon in Your Home

How do you reduce indoor radon gas levels when you are dealing with a colorless, odorless gas? (Related: A Comprehensive Guide To Household Indoor Air Quality) To help you get started, here are some simple, practical tips you can follow to reduce your indoor radon levels at a given time.

  • Ensure proper ventilation: Open any windows, doors, and vents in your home when you can. Make sure there is proper airflow throughout your house.
  • Seal access points: One way to prevent radon entry is to seal all the possible access points. For instance, you may buy draft excluders and rubber seals to use for doors. If your primary goal is to minimize radon gas levels in the basement area, this method will benefit you the most.
  • Seal any cracks: Most commonly, radon enters your home in the ground. It's best to seal any large cracks or openings as soon as possible. Not to mention, it may also reduce your monthly energy consumption.
  • Caulking: You can also use different caulking products to seal interior entry points, such as floors and walls.

Benefits of Radon Mitigation

Let's get down to the primary benefit of a radon mitigation system: reduced risk of lung cancer. The system is known to be effective immediately after 24 hours of setting up, keeping low levels of radon in your home with the fan working around the clock.

Another known benefit of radon mitigation is decreased moist soil air infiltration with radon. It reduces the humidity in your basement area. If you're dealing with a rather severe radon problem in your home, it would be best to first solve the issue before considering putting your property for sale. Current occupants in your property and prospective buyers will benefit from the reduced health risks.

It would be challenging to sell a house with high levels of radon. Although it's not impossible, the process will be tough.

Hiring a Qualified Radon Service Provider

The EPA does not recommend a DIY radon mitigation approach. Those who attempt to pull off a DIY project but lack the expertise may unwittingly increase the radon levels inside the home or compromise the air quality. Therefore, it is ideal to avail the services of a professional radon remediation company to do the job correctly. Keep in mind that the process requires specific skills as well as technical knowledge.

For starters, you can find nationally-certified radon measurement and mitigation companies (such as that of the National Radon Proficiency Program and National Radon Safety Board) in your locality. In some states, radon contractors need to be certified or licensed before operating on radon mitigation projects. Hence, make time to call your local radon office to determine the qualified service providers in the area.

Here are some other guide questions to ask your local radon mitigation professional before signing up for their service:

  • Do you have insurance for your labor?
  • Do you have testimonials showing satisfied results from previous clients?
  • Is there a written contract containing the cost breakdown of the system?
  • Do you include a post-mitigation test to ensure the system is up and running?
  • Do you offer a warranty for your services?

Radon Reduction System Maintenance

Some of you may be wondering, what does a radon mitigation system maintenance entail? Well, the system requires occasional maintenance similar to that of a chimney or furnace. For active systems (those powered with a fan), you will need to keep a close eye on your warning device or manometer. Doing so will ensure that the new radon reduction system is working as intended. Most radon fans have a life expectancy of five years. After that period, you may need to have your fan serviced, repaired, or replaced entirely with a brand new unit.

When it comes to testing your home for radon levels, it's best to schedule at least once in two years. It will give you peace of mind on having low and safe radon levels at home. Depending on your radon mitigation system, ensure the fan is not turned off. It must run around the clock to ensure the system is functioning correctly.

The filters in a heat recovery ventilator or HRV need frequent cleaning and changing twice a year (at $14 to $34 per piece). HRV is designed to increase ventilation in your home, reducing the radon levels in the process. You will also need to inspect the dedicated vent that brings fresh air for debris, leaves, or twigs. Lastly, have your ventilator assessed by an HVAC professional to ensure its optimal performance.

How to Save Money on Radon Mitigation System Cost

Before you know it, the average cost of radon mitigation in your area may exceed your budget. There are soft costs and other additional expenses to the project which may add up quickly. Fortunately, you do not need to settle with a subpar radon mitigation contractor or opt for a risky DIY project.

If you want to cut corners efficiently, here are some simple ways you can do to save money on radon mitigation costs.

  • Ask for any applicable seasonal company discounts
  • See if there's a covered warranty included in your system
  • Discuss your budget with your chosen radon mitigation professional. It can help you determine the best system type that will work best for your situation and home needs without breaking the bank.
  • Ask if you can have a discount if you submit a testimonial video.
  • Do your research if you are eligible for certain tax advantages or local home repair grants.
  • Ask your contractor if there's a discount upon paying in cash

Radon Mitigation: Frequently Asked Questions (FAQs)

Do I need further testing after installing a radon mitigation system?

Yes, it will be good to retest your radon mitigation system after installation to ensure that the system works, and the radon level is low. However, the testing must not be any sooner than 24 hours or later than 30 days. State or local authorities also recommend checking your system every two years. If your property undergoes significant alteration, it's best to have radon retesting as well.

What is a safe level of radon?

As of writing, there remains no known safe level of radon but, EPA recommends getting your home fixed by a professional if the radon level is above four pCi/L (picocuries per liter). Most companies promise to reduce radon levels down to 0.4 pCi/L, which is the average outdoor level. Regardless, most professionals will work on lowering your property's current radon levels as low as possible.

Can I sell a house with high radon levels?

While there are no existing laws that may prevent you from selling your house with elevated radon, some states will still require you to disclose test results of your radon level. In particular, Montgomery County, Maryland, requires favorable radon test results for all home sales. It's still recommended to do frequent radon testing on your property to ensure the safety of all current (and future) occupants. Meticulous buyers may look into the current levels of radon, and if the results are somewhat unfavorable, they may just reconsider or look at other properties on the market instead.

Final Thoughts

If your property is dealing with a radon gas problem, it's best to find a solution at once. Frequent exposure to high levels of radon may put your health at risk.

Not to mention, it will also decrease your property's value on the market. Don't let the problem linger longer than needed. Contact local radon mitigation systems today!

Kenneth Wilson
September 25, 2021
Cost Guides, Interior

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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