UKHSA/BGS Indicative Atlas of Radon: area class, Great Britain

Radon levels by area

Radon is a natural radioactive gas from the ground; long-term exposure to high indoor levels raises lung-cancer risk. These pages give the UKHSA/BGS radon Affected-Area class for higher-radon outcodes across Great Britain, and explain what the class means when you are buying, so you know whether to ask the seller about a test.

46 higher-radon areas (Class 3+) · the class is the proportion of homes in a 1 km tile, never a single property's indoor radon level.

The Affected-Area class estimates how many homes across a 1 km tile are likely to be at or above the radon Action Level. It is never the indoor radon level of any individual property. Only a UKHSA measurement test gives a specific home's own level.

Higher-radon areas (Affected-Area Class 3+)

CT16Class 6 · 30%+ of homes

Dover

TR1Class 6 · 30%+ of homes

Truro

BA1Class 5 · 10–30% of homes

Bath

BA2Class 5 · 10–30% of homes

Bath (south & west)

BB7Class 5 · 10–30% of homes

Clitheroe

BN3Class 5 · 10–30% of homes

Hove

BN7Class 5 · 10–30% of homes

Lewes

BS8Class 5 · 10–30% of homes

Clifton, Bristol

CV1Class 5 · 10–30% of homes

Coventry

EX34Class 5 · 10–30% of homes

Ilfracombe

LA1Class 5 · 10–30% of homes

Lancaster

LL57Class 5 · 10–30% of homes

Bangor, Gwynedd

NN1Class 5 · 10–30% of homes

Northampton

PL4Class 5 · 10–30% of homes

Plymouth

BS1Class 4 · 5–10% of homes

Bristol city centre

BS6Class 4 · 5–10% of homes

Redland & Cotham, Bristol

HG1Class 4 · 5–10% of homes

Harrogate

LS10Class 4 · 5–10% of homes

Hunslet, Leeds

ME14Class 4 · 5–10% of homes

Maidstone

S1Class 4 · 5–10% of homes

Sheffield city centre

SA1Class 4 · 5–10% of homes

Swansea

TQ1Class 4 · 5–10% of homes

Torquay

WF1Class 4 · 5–10% of homes

Wakefield

WV1Class 4 · 5–10% of homes

Wolverhampton

AL1Class 3 · 3–5% of homes

St Albans

BA6Class 3 · 3–5% of homes

Glastonbury & Street

BD1Class 3 · 3–5% of homes

Bradford

BL1Class 3 · 3–5% of homes

Bolton

BN1Class 3 · 3–5% of homes

Brighton

DT1Class 3 · 3–5% of homes

Dorchester

EX4Class 3 · 3–5% of homes

Exeter

GL50Class 3 · 3–5% of homes

Cheltenham

HR1Class 3 · 3–5% of homes

Hereford

HR4Class 3 · 3–5% of homes

Hereford

HX7Class 3 · 3–5% of homes

Hebden Bridge, Calderdale

LS1Class 3 · 3–5% of homes

Leeds city centre

LS6Class 3 · 3–5% of homes

Headingley, Leeds

ME1Class 3 · 3–5% of homes

Rochester, Medway

NP20Class 3 · 3–5% of homes

Newport

PL1Class 3 · 3–5% of homes

Plymouth city centre

PO1Class 3 · 3–5% of homes

Portsmouth

S10Class 3 · 3–5% of homes

Sheffield (west)

SL6Class 3 · 3–5% of homes

Maidenhead

SY1Class 3 · 3–5% of homes

Shrewsbury

TQ14Class 3 · 3–5% of homes

Teignmouth & Dawlish

WD17Class 3 · 3–5% of homes

Watford

Check a specific address

The class is area-level. The £24.99 Complete report includes the radon class for one exact address alongside the ground-stability, flood and other checks, and points you to a UKHSA test for the property's own measured level: the full risk picture before you offer.

Get My Full Property Report (£24.99)Order a UKHSA radon test

Frequently asked questions

What is a radon Affected-Area class?

It is the UKHSA/BGS Indicative Atlas class (1–6) for a 1 km grid tile: an estimate of the PROPORTION OF HOMES in that tile likely to be at or above the radon Action Level. Class 2 and above is a radon Affected Area. The class describes an area, not the radon level in any one property.

Does a class tell me my home's radon level?

No. The class is an area estimate of how many homes are likely to be above the Action Level, so it cannot tell you a specific property's level. Radon varies house by house depending on geology, construction and ventilation. The only way to know a home's level is a UKHSA measurement test, usually over three months.

What should a buyer do in a higher-radon area?

Ask the seller whether the property has been tested and what the result was, and whether radon protective or remedial measures are fitted. You can order a UKHSA test kit, and new build in higher-class areas requires radon protective measures under building regulations. Radon is reducible. Sump systems and improved ventilation typically bring high levels down.

Which areas are listed?

Only higher-radon areas, Affected-Area Class 3 and above (an estimated 3% or more of homes at or above the Action Level), are listed and indexed, because lower-class areas are not differentiated enough to be useful. Coverage is Great Britain; Northern Ireland is served by UKHSA's UKradon service.

Sources