Selling a House With Radon in Colorado: What Every Seller Must Know

If you are putting your Colorado home on the market, radon is one of the most common issues to surface during inspection, and one of the easiest to handle if you plan ahead. Knowing the rules and your options up front can mean the difference between a smooth closing and a deal that stalls at the finish line.

Colorado Has a Radon Disclosure Law

As of recent state law, Colorado sellers are required to provide buyers with a radon brochure and disclose what they know about the home’s radon levels and any existing mitigation system before closing. Being transparent is not just a legal requirement, it builds trust and prevents nasty surprises that can blow up a deal late in the process.

• Provide the state-required radon disclosure and informational brochure.
• Disclose prior test results and whether a mitigation system is installed.
• Share documentation and warranties for any existing system.
• When in doubt, over-disclose. Hidden issues erode buyer confidence.

Why Radon Comes Up in Almost Every Inspection

Because all of Colorado sits in EPA Radon Zone 1, radon testing is a standard part of most home inspections here. Buyers and their agents know the risk, so a radon test is often built right into the inspection contingency. If the result comes back at or above 4.0 pCi/L, expect the buyer to request mitigation before they will move forward.

A radon problem rarely kills a deal. An unaddressed radon problem often does.

Your Options as a Seller

If a test reveals high radon, you generally have three paths. You can install a mitigation system before listing to remove the issue entirely, negotiate to install one once it comes up in inspection, or offer the buyer a credit to handle it themselves. Installing proactively is often the smartest move because it removes uncertainty and can even become a selling point.

• Mitigate before listing: turns a liability into a marketing advantage.
• Mitigate during escrow: a fast install keeps the timeline on track.
• Offer a credit: simplest for you, but buyers may overestimate the cost.

A Mitigation System Can Be a Selling Point

Far from a red flag, an installed radon system signals to buyers that the home has been cared for and that a known regional risk has already been handled. Paired with a recent passing test and a transferable warranty, it can make your listing stand out and speed up the sale.

Selling soon? Custom Radon can install a system quickly to keep your closing on schedule, provide the documentation buyers want, and guarantee levels below 4.0 pCi/L with a lifetime warranty. Schedule a free in-person estimate and we will help you turn radon from a roadblock into a non-issue.