RadonProsCertified Directory

Buying or Selling a Home? Radon on a Deadline.

Over 40% of radon mitigation happens during real estate transactions. Here's how to handle it without blowing your closing date.

Check Your Timeline

The Real Estate Radon Timeline

Here's the typical process from test to close. Total time: 7-14 days if everything goes smoothly.

1

Radon Test

2-7 days

Short-term test requires closed-house conditions for at least 48 hours. Some testers use continuous monitors that give results in 48 hours. Charcoal canisters take 2-7 days plus lab time.

2

Negotiate

1-3 days

If test results are above 4.0 pCi/L, negotiate who pays for mitigation. It's always negotiable -- sometimes the seller pays, sometimes the buyer, sometimes they split it. Get it in writing in the purchase agreement.

3

Mitigate

1 day

Most residential mitigation systems are installed in a single day. The contractor drills a hole in the slab or installs a membrane over the crawlspace, runs PVC pipe to the roof, and mounts a fan. It's not a big construction project.

4

Re-Test

48+ hours

After installation, wait at least 24 hours for the system to stabilize, then run a 48-hour test. If levels are below 4.0 (most systems get below 2.0), you're clear to close.

5

Close

With a passing re-test in hand, you can close on schedule. Keep the test documentation for your records.

Who Pays for Radon Mitigation?

There's no universal rule. It's part of the negotiation, just like any other inspection finding. Here's what we see:

  • Seller pays (most common): Seller installs the system before closing. Buyer gets a mitigated home.
  • Buyer pays: Buyer negotiates a price reduction ($800-$1,500 credit) and handles installation after closing.
  • Split the cost: Both parties share the expense. Common in competitive markets.
  • Seller provides credit: Seller gives buyer a credit at closing specifically for radon mitigation.

Whatever you agree to, get it written into the purchase agreement or an amendment. Verbal agreements don't hold up.

What to Include in Your Purchase Agreement

  • Who is responsible for radon testing (buyer or seller)
  • Who pays for mitigation if levels exceed 4.0 pCi/L
  • Requirement that a certified professional (NRPP or NRSB) performs the work
  • Post-mitigation testing requirement before closing
  • What happens if the re-test still shows elevated levels
  • Deadline for mitigation completion (tied to closing date)

For Real Estate Professionals

Need to refer a client to a radon professional? Our directory shows NRPP/NRSB certified contractors with real estate experience. You can share a direct link to your client's local results.

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