What Colorado Law Actually Requires: SB23-206, in Plain English
Since August 7, 2023, Colorado's SB23-206 has put radon squarely into every residential transaction. What it does, without the legalese:
- Every residential sales contract carries a bold CDPHE warning recommending that buyers test the home for radon.
- Sellers must disclose what they know — any radon test results, measured levels, and mitigation records — and must provide the buyer with the CDPHE radon brochure.
- Landlords owe tenants the same: disclosure of known radon information plus the brochure, with a signed acknowledgment from the tenant.
Just as important is what the law does not do: it's disclosure-only. Nobody is required to test, and nobody is required to mitigate. But once a high result exists, it exists — it goes in the disclosure file for this deal and every future one. That single fact drives most of the negotiating logic below.
The Objection-Deadline Playbook
You're under contract, the inspection test came back high, and the objection deadline is close. Here's the sequence that keeps deals together:
- 1. If the result is near 4.0, retest before you negotiate hard. Short-term tests bounce. A 4.2 can be a 3.5 next week — and a 3.9 can be a 6 in January. A result hovering at the action level is worth a second measurement before anyone spends negotiating capital on it.
- 2. If it's clearly high, pick from the three standard outcomes. In Colorado deals these are: the seller installs a system before closing (cleanest for everyone — the buyer moves into a fixed house); the seller gives a closing credit, typically $1,200–$2,000, and the buyer handles it; or the buyer takes it on post-close, usually in exchange for a concession elsewhere.
- 3. Whoever pays, verify. A post-mitigation verification test — 48 hours, a real number — is what turns "we installed a system" into a documented fix that satisfies the buyer, the lender's timeline, and the next disclosure form.
Never Walk Away Over Radon
Worth saying plainly: radon is the most fixable finding in an inspection report. A cracked foundation is a project. A failing roof is a project. Radon is a designed system, installed in about a day for most single-foundation homes, that reliably brings levels down — mitigated homes typically land under 2 pCi/L, often under 1. If you love the house, a high radon number is a negotiating item, not a reason to lose it. And since about half of Colorado homes test high, the next house you fall for has roughly a coin-flip chance of the same conversation.
Transaction Tests Need a Licensed Measurement Professional
The free county kit is a fine screening tool for your own curiosity — but when money changes hands based on the result, the test itself has to hold up. Colorado law (HB21-1195, since July 2022) requires anyone offering radon measurement services to hold a DORA license, and transaction tests are run with continuous radon monitors that log hourly readings and flag tampering — because in a negotiation, both sides need to trust that nobody opened the windows on day two. Verify any tester at DORA's Check a License lookup — including us.
Deadlines Are Our Normal
Real-estate radon work runs on the contract's clock, not the contractor's. What that looks like in practice: diagnostics and a written scope quickly after the call, installation scheduled to land inside the resolution deadline, and the 48-hour verification test completed before closing, so the file that goes to the closing table shows a number, not a promise. If your deadline is measured in days, say so when you call — that's the first thing we schedule around.
For Realtors
Agents move most of the radon conversations in this valley, so here's the short version for your buyers and sellers:
- For the panicked buyer: radon is common here — roughly 40–50% of tested Pitkin County homes come back high — and it is fixable, quickly, for about the cost of a used snowblower. It should never kill a deal on a house they love. The right move is a licensed retest if the number is borderline, then one of the three standard remedies.
- For sellers: a known high result must be disclosed, so the strategic play is usually to fix it and reframe. A documented system with a verified low number turns a disclosure liability into a listing feature.
- An existing system is a plus, not a red flag. It means the soil-gas question has already been answered and solved. Have the buyer check the manometer, get the system inspected if it's older, and ask for the most recent test result. Systems don't hurt resale; undisclosed high tests do.
- Keep our number handy: we quote from test reports over the phone and schedule to objection deadlines. That's the whole pitch.