Radon Levels in Colorado Homes: What Buyers Should Know Before Closing

If you're buying a home in Colorado, one environmental issue should always be on your radar: radon gas.

Radon is extremely common throughout Colorado, and many buyers are surprised to learn just how frequently homes test above safe levels. Because radon is invisible and odorless, the only way to know if a home has elevated radon levels is through professional testing.

For buyers, understanding how radon works—and testing for it during the inspection period—can protect both your health and your finances.

What Is Radon?

Radon is a naturally occurring radioactive gas produced when uranium in soil and rock breaks down. It moves through the ground and can enter homes through small openings in the foundation, including:

• Foundation cracks

• Expansion joints

• Pipe penetrations

• Crawlspaces

• Sump pits

Once radon enters a home, it can become trapped and accumulate to dangerous levels.

Because radon has no smell, color, or taste, homeowners typically have no indication it's present without a professional test.

Why Radon Is Dangerous

Long-term exposure to radon increases the risk of lung cancer. In fact, the United States Environmental Protection Agency identifies radon as the second leading cause of lung cancer in the United States, behind smoking.

The risk comes from inhaling radioactive particles that can damage lung tissue over time. While the effects aren’t immediate, prolonged exposure in a home with elevated radon levels can significantly increase health risks for occupants.

Because people spend so much time at home, testing for radon during the home-buying process is one of the simplest ways to reduce long-term exposure.

Radon Is Extremely Common in Colorado

Colorado’s geology makes it one of the highest radon regions in the country.

According to statewide testing data, about half of homes in Colorado test above the recommended safety level.

That means when buying a home in Colorado Springs, there's essentially a 50/50 chance the property could have elevated radon levels.

Even homes that appear identical—or homes in the same neighborhood—can have drastically different radon readings. The only reliable way to know the level in a specific home is through testing.

What Radon Level Is Considered Unsafe?

The United States Environmental Protection Agency recommends taking action when radon levels reach 4.0 picocuries per liter (pCi/L) or higher.

To put this into perspective:

Radon Level	Meaning
0–2 pCi/L	Typical outdoor levels
2–4 pCi/L	Moderate risk
4+ pCi/L	EPA recommends mitigation

Many homes in the Colorado Springs area fall above this 4.0 pCi/L threshold, which is why radon testing is considered a standard part of many home inspections across the Front Range.

image courtesy of: epa/gov

How Radon Testing Works During a Home Purchase

A professional radon test is simple and non-invasive.

The test device is placed in the lowest livable area of the home and measures radon levels continuously for 48 hours.

During the test period, the home remains under closed-house conditions, which ensures accurate readings.

Once the test is complete, the monitor provides a detailed report showing the average radon concentration in the home.

Because the testing window fits within most inspection timelines, buyers can receive results before the end of their due diligence period.

Why Professional Testing Matters

Not all radon tests are the same.

Our company uses professional-grade continuous radon monitors, including the Corentium Airthings Pro, which are EPA-recognized testing devices.

These monitors provide several advantages over basic DIY kits:

• Continuous radon monitoring over the entire test period

• Tamper detection to ensure accurate readings

• Highly precise measurement technology

• Detailed digital reports

Just as importantly, these devices require annual calibration to maintain accuracy. Proper calibration ensures that every test provides reliable data that buyers, sellers, and real estate professionals can trust.

In real estate transactions where negotiation decisions may depend on the results, accuracy matters.

What Happens If Radon Levels Are High?

If a radon test comes back above 4.0 pCi/L, buyers typically have an opportunity to request mitigation as part of the inspection negotiation.

Radon mitigation systems are very effective and typically involve:

• A vent pipe system installed beneath the foundation

• A fan that pulls radon gas from beneath the home

• Venting the gas safely above the roofline

These systems often reduce radon levels dramatically.

The key advantage of testing during the inspection period is that buyers may be able to request the seller install the mitigation system before closing.

Without testing, a buyer may discover elevated radon levels after moving in, leaving them responsible for the mitigation cost themselves.

Homes With Existing Mitigation Systems Still Need Testing

Another common misconception is that homes with radon mitigation systems no longer need testing.

In reality, these systems should be tested every two years to confirm they are still functioning properly.

Fans can fail, pipes can shift, and system performance can change over time. Testing ensures the system continues to keep radon levels below recommended limits.

When buying a home with an existing mitigation system, testing verifies that the system is still effectively protecting the home.

Radon Testing Is One of the Most Valuable Add-On Inspections

For buyers in Colorado Springs, radon testing is one of the most important environmental tests available during the inspection period.

The process is simple:

✔ The test takes only 48 hours

✔ It requires no invasive work in the home

✔ It provides clear, actionable data

✔ It may allow buyers to negotiate mitigation costs with the seller

Considering how common elevated radon levels are across Colorado, testing provides peace of mind that many buyers find invaluable.

Final Thoughts for Homebuyers

Radon is a serious but manageable environmental risk. The key is simply knowing whether it’s present in the home you're buying.

With roughly half of Colorado homes testing above recommended levels, skipping radon testing can mean overlooking an issue that is both common and easily addressed.

A professional 48-hour test during the inspection period gives buyers the information they need to make informed decisions and, when necessary, negotiate solutions before closing.

FAQ: Radon Testing in Colorado Springs

Do most homes in Colorado Springs have radon?Radon is very common in Colorado. Roughly half of homes statewide test above the recommended EPA action level of 4.0 pCi/L.

How long does a radon test take during a home inspection?A professional test runs for 48 hours to provide accurate readings.

Can radon be fixed if levels are high?Yes. Radon mitigation systems are highly effective and are commonly installed in Colorado homes.

If a home already has a mitigation system, do I still need a test?Yes. Mitigation systems should be tested every two years to confirm they are still functioning properly.