What is radon?

Radon is a naturally occurring radioactive gas, produced by the radioactive decay of Uranium (238U). Uranium is found in small quantities in all soils and rocks throughout the UK. It is not possible to see or smell radon and specialist equipment is required to detect it.

The data used by Groundsure

The data used in our reports is taken from a joint database produced in 2007 by the British Geological Survey (BGS) and Public Health England (formerly the Health Protection Agency). The data is considered to be accurate to 50m. It is the most up to date and accurate data available on the market. Where radon is present, we identify the percentage of properties likely to be affected and what level if any protection measures are required.

The recommended Action Level

For residential properties the recommended Action Level is 200 Becquerels per cubic metre (Bq/m3) and 400 Bq/m3 for commercial properties.  Where more than 1% of properties are estimated to exceed the Action Level the area should be regarded as radon affected. However, this data is not property specific and it is recommended a property specific measurement be taken. In situ detectors can be purchased from UK radon for £49.80 inc. VAT. Checks are also available for commercial properties.

New builds and extensions

As described in publication BR211, by the Building Research Establishment (BRE), radon protective measures are required for some new dwellings and extensions to existing dwellings that are built in radon affected areas. Radon Protection Measures are required where over 3% of properties are considered as radon affected. If your property has been recently developed we would recommend contacting the Building Control Department at the local authority for further information.

Differences in data

Many local authorities (including CON29 searches) and freely available publications use the Indicative Radon Atlas when providing radon information. This data provides the highest radon potential within 1km. The Groundsure data is of a much higher resolution and is accurate to 50m. Where there is a discrepancy, the data used by Groundsure should be relied upon.