Check radon before you buy a house
Radon is a natural radioactive gas that comes up from the ground. You can’t see or smell it, and levels vary a lot from place to place. The UK Health Security Agency says it is the second biggest cause of lung cancer after smoking.
Free to start with a postcode. No account needed. See an example report.
How to check radon for a property
Check the area
The full report gives the radon potential for the 1 km square around the house: the share of homes there estimated to be above the radon action level.
Understand the band
Where 1% or more of homes are estimated to be above the action level, the area is a radon Affected Area. The bands go from under 1% up to over 30%.
Ask the seller
Ask whether the home has been tested for radon, what the result was, and whether radon protection, such as a sump or a membrane, has been fitted.
Test the house
Only a test in the home measures its radon level. The usual test runs for three months, so in a higher-radon area it’s worth planning one once you move in.
What we check
- Radon potential for the 1 km square around the houseFull report
- Whether it’s a radon Affected Area, and what to askFull report
Coverage: England, Scotland and Wales.
Sources: British Geological Survey and UK Health Security Agency radon data. All data sources
Why radon matters when you buy
Raised radon is common in some parts of the country and rare in others. Knowing the area’s potential tells you whether to ask about testing and protection before you commit.
A higher-radon area isn’t a reason on its own to walk away. Raised levels in a home can usually be reduced, for example with a radon sump, and a specialist can quote for it.
Questions to ask the seller, your solicitor or surveyor
- Has the house been tested for radon, and what was the result?
- Was radon protection fitted when it was built or since?
- If levels were raised, what was done, and was it tested again afterwards?
The full report ties questions like these to what it finds at the house.
Common questions
What is a radon Affected Area?
An area where 1% or more of homes are estimated to have radon above the action level of 200 becquerels per cubic metre.
Does the area figure tell me the radon level in the house?
No. It’s the share of homes nearby estimated to be above the action level. Two neighbouring houses can have very different levels, so only a test in the home tells you its level.
Should I avoid buying in a radon area?
That’s your decision, and we don’t say whether to buy. Raised radon can usually be reduced. Use the area figure to decide what to ask the seller and whether to test.
Official records, not advice. We never score properties or tell you whether to buy. Check a postcode