The UK Radon Association has warned landlords in five areas of Britain about higher radon risk, linking the invisible gas to an estimated 1,100 lung cancer deaths in the UK each year.
The warning, highlighted on 6 November, names Barry, Brighton and Hove, Coventry, Leeds and Lincoln as places where updated geological mapping has changed the estimated likelihood of homes containing high radon levels.
Rental homes carry extra exposure because tenants seldom order gas tests themselves and landlords retain the duty to keep properties free from serious health hazards. Affected owners in the five areas now face a direct prompt to check the latest map and test.
UK Radon Association names five higher-risk areas
Radon is colourless and odourless, and it has long been linked with the South West. The association said modern mapping published in 2022, backed by a larger set of test results, gave a far clearer picture of risk across Britain.
Four years on, public awareness has not kept pace, according to the association. Many owners still rely on old assumptions about where risk exists.
Dr Maria Dugdale, chair of the UK Radon Association, said levels had not suddenly spiked. She said radon had always been present and modern mapping had given a far clearer picture since 2022. “Large numbers of people are still relying on outdated assumptions about where radon risk exists or remain unfamiliar with the risks posed by the gas.”
Brighton, Barry, Coventry, Leeds and Lincoln ratings change
The revised ratings run from less than 1 percent to greater than 30 percent of homes likely to have high concentrations. An area counts as a Radon Affected Area where the estimate reaches 1 percent or higher.
In Brighton and Hove, large parts of the city have moved from the 1-3 percent band to 5-10 percent, meaning up to one in 10 homes could be affected. In Barry, 83 percent of the mapped CF62 district now sits in the 10-30 percent band, up from 5-10 percent.
Coventry was not previously classed as affected but much of the city and its surrounds now sits in the 5-10 percent band, with pockets at 10-30 percent. The Leeds suburb of Farsley has risen from less than 1 percent to 5-10 percent. Areas east and south of Lincoln now show greater than 30 percent risk, meaning more than one in three homes could be affected.
This follows Landlord Knowledge’s report on the updated HHSRS guidance for England landlords, which set out how councils assess serious housing hazards. The radon update adds a location-specific test prompt on top of that standing repair duty.
What landlords in affected areas should check now
The association urges owners to check the current map, order a test where the rating is 1-3 percent or higher, review workplace duties under Health and Safety Executive guidance for relevant buildings, and act where a test shows raised levels.
Government guidance on radon sits alongside wider duties on damp, mould and cold under the Awaab’s Law consultation for private landlords, which proposes fixed repair deadlines. Testing now creates a dated record that an owner has acted.
Further detail on test ordering and mitigation steps is available on the UK Radon Week map and testing hub.
What this means for landlords
- If you let in Barry, Brighton and Hove, Coventry, Leeds or Lincoln: check the current radon map for each postcode and order a test where the band is 1 percent or higher.
- Watch for: tenant queries about testing and local authority questions where hazard ratings are under review.
- Bottom line: a low-cost test now is simpler than a dispute later over an undisclosed health risk.
Editor’s view
Radon rarely features in landlord compliance lists, which is exactly why this warning matters. Owners in the five named areas should treat a test as basic due diligence and keep the result on file.
Author: Editorial Team – UK landlord & buy-to-let news, policy, and finance
Published: 09 November 2026
Sources: UK Radon Association, Health and Safety Executive
Related reading: Government updates HHSRS guide for England landlords
