Radon testing when buying or selling a home in NH
How radon tests work during a home sale in NH, and what buyers and sellers can ask for.
EPA recommends testing for radon when buying or selling a home. NH DHHS's 2016 radon fact sheet notes that New Hampshire law does not require radon testing for real estate transactions, so whether a test happens is up to the buyer and seller.
How the test is usually done
Home sales move fast, so a short-term test is common. NH DHHS says to use two test kits side by side, at least 4 inches apart, and average the two results. If one reads much higher or lower than the other, there's probably a problem with a kit and the test should be repeated.
NH doesn't require radon testers to be certified, but NH DHHS recommends a nationally certified radon measurement professional, especially for a real estate transaction. Directories: NRPP and NRSB.
For buyers
- Ask whether the home has been tested, when, and the result.
- Ask whether a mitigation system is installed and whether it was retested afterward.
- If the home has a private bedrock well, consider a water radon test too (radon in well water).
For sellers
- Testing ahead of listing lets you fix a high result on your own schedule.
- Keep test reports and mitigation paperwork to share with buyers.
In New Hampshire? Order a free state test kit or see radon by NH county.
More guides
- How to read a radon test result (pCi/L)
- Short-term vs long-term radon tests
- Radon in well water in New Hampshire
- Radon mitigation basics
- When to retest for radon
Sources
- EPA, Home Buyer's and Seller's Guide to Radon
- NH DHHS, Testing for Radon
- NH DHHS Environmental Public Health Tracking, “Spotlight: Radon Risk,” Jan 2016 (NH DES test data, 1988–2011)
Sources checked October 31, 2026. Spot an error? Send a correction.