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 — £24.99Order 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 — 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