Do You Need a Radon Test Before Closing on a Denver Home? What Colorado Law Says
If you're buying a home in Denver, you've probably wondered whether a radon test is required before closing. The short answer is no, but the full answer is more useful. Colorado law requires sellers to disclose radon information even if they don’t have to test for it. That distinction matters, and it's worth understanding before you sign.
Is Radon Testing Legally Required in Colorado?
No, Colorado law doesn't require a radon test before you close on a home. What it does require is disclosure. Every residential sales contract in the state must include a specific radon statement, which recommends testing in lieu of a mandate.
What the Disclosure Law Actually Says
Colorado Revised Statute 38-35.7-112 gives buyers the right to know whether anyone has tested the property for radon. The law goes further than a simple checkbox. Every contract must include a bold-faced statement warning that radon exposure can raise the risk of lung cancer. That same statement must recommend testing and mitigation in plain language.
If the seller has test results, they have to share them. But if the home has never been tested, there's nothing on record to disclose. That gap is why so many Denver buyers choose to test on their own.
Why Denver Buyers Test Anyway, Even Without a Legal Requirement
Denver sits along Colorado's Front Range. This region has some of the highest radon potential in the country. In fact, 53 of the 64 counties in Colorado have Zone 1 radon levels. That’s the highest level, according to the EPA, and comes with the recommendation to install a radon reduction system.
How Much Does Radon Testing Actually Cost?
Cost is one of the biggest reasons buyers skip testing, but the numbers don't support that decision. A professional radon test in the Denver area typically runs around $200, and a basic consumer kit costs even less.
If your results come back elevated, mitigation is your best option. A typical fan installation in Denver costs around $700. A full installation system starts around $1,500, with prices varying depending on the size and complexity of the system required. Weighed against the price of a house, though, that range is a rounding error.
When Should You Test During the Closing Process?
Most Denver buyers test during the inspection period, right alongside the general home inspection. A short-term test usually takes 48 hours to produce results. That often fits inside a standard objection deadline. Scheduling it early gives you room to negotiate if something comes back elevated.
What Are Your Options If Radon Levels Come Back High Before Closing?
Testing before closing gives you leverage that testing after closing never will. Once you have a result in hand, you typically have a few paths forward:
Ask the seller to install a mitigation system before the sale closes
Negotiate a credit at closing and handle the installation yourself
Renegotiate the purchase price to reflect the cost of the fix
None of those options exist once you already own the home.
So, Do You Need a Radon Test Before Closing?
Legally, no. Practically, yes, especially in Denver or other Front Range cities like Fort Collins and Colorado Springs. A test costs little compared to what you'd spend fixing an issue after closing and can make a significant difference for your health. It also gives you real leverage in negotiations if levels come back elevated.
The law leaves the choice to you, so make the one that protects your health and your budget.
