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

Radon levels in S1: Sheffield city centre

Class 4of 6 — 5–10% of homes at/above the Action Level

S1 (Sheffield city centre) is in radon Affected-Area Class 4 of 6 — 5–10% of homes estimated at or above the radon Action Level. This is the UKHSA/BGS Indicative Atlas class for the 1 km grid tile covering the area: it estimates the PROPORTION OF HOMES likely to be at or above the radon Action Level, NOT the radon level in any specific property. New homes here typically need radon protective measures. Only a radon measurement test gives a particular home's own level.

Affected-Area CLASS = proportion of homes in the 1 km tile, never a single property's indoor radon level.

Where S1 sits on the radon scale

Class 1less than 1% of homes at/above the Action Level
Class 21–3% of homes at/above the Action Level
Class 33–5% of homes at/above the Action Level
Class 4This area5–10% of homes at/above the Action Level
Class 510–30% of homes at/above the Action Level
Class 630% or more of homes at/above the Action Level

Based on the 1 km Atlas tile SK3587 covering the S1 representative point.

What Class 4 means for buyers

Radon is a natural radioactive gas from the ground; long-term exposure to high indoor levels raises lung-cancer risk. The class tells you the area is more likely to contain homes above the Action Level — it does not tell you a specific home's level, which depends on geology, construction and ventilation and can only be found by a measurement test.

In an area of this class, new homes are generally required to include radon protective measures under building regulations, and buyers of existing homes should ask whether the property has been tested. Good news: radon is reducible — sump systems and improved ventilation typically bring high readings down.

Order a UKHSA radon test

Check a specific S1 address

This page is the area class. The £24.99 Complete report includes the radon class for one exact address alongside the ground-stability, flood and other checks — the full risk picture before you offer.

Get My Full Property Report — £24.99Ground-stability tool

Frequently asked questions

Is S1 a radon area?

Yes — S1 (Sheffield city centre) falls in radon Affected-Area Class 4 of 6 in the UKHSA/BGS Indicative Atlas, meaning 5–10% of homes estimated at or above the radon Action Level. It is a radon Affected Area (Class 2 and above). The class describes the proportion of homes across the 1 km tile, not the level in any single property.

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

No. The Affected-Area class is an area estimate of how many homes are likely to be at or 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 radon measurement test, usually over three months.

What should a buyer do about radon here?

Ask the seller whether the property has been tested and what the result was, and whether any radon protective or remedial measures are fitted. For a purchase, you can order a UKHSA test kit, and for new build in higher-class areas, building regulations require radon protective measures. Radon is reducible — sump systems and improved ventilation typically bring high levels down.

How do I check radon for a specific S1 property?

The class is area-level. The HouseCheckup 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.

Sources

Indicative Atlas of Radon — © Crown copyright UKHSA; contains British Geological Survey materials © UKRI. Open Government Licence v3.0.