Where the data comes from

Every report names its sources beside each finding, with the date it was read. This page lists them in one place, with the licence, so you can read the same records yourself.

Postcodes

postcodes.io, an open service built on Office for National Statistics and Ordnance Survey open data. Gives the coordinates, the council and the country for a postcode. Open Government Licence v3.0. https://postcodes.io

Radon

The Indicative Atlas of Radon in Great Britain, produced jointly by the British Geological Survey and the UK Health Security Agency, read through the BGS open map service, layer Radon.1km. Each 1 km square carries the highest radon potential found in it, as a class from 1 to 6. Open Government Licence v3.0. Contains British Geological Survey materials copyright UKRI 2026. The UKHSA per address search costs £3.90 at https://www.ukradon.org/services/address_search and the free maps are at https://www.ukradon.org/information/ukmaps The Action Level, the measurement pack and the typical cost of each fix are read from ukradon.org on the date printed in the report. The employer duty comes from the Ionising Radiations Regulations 2017 and the Health and Safety Executive's radon page.

Attribution

Contains public sector information licensed under the Open Government Licence v3.0. Contains British Geological Survey materials copyright UKRI 2026. Contains OS data copyright Crown copyright and database right 2026.