How does Coal Authority Development High Risk Area affect conveyancing?

The Coal Authority publishes the Development High Risk Areas (DHRA): the parts of the coalfield where past mining is close enough to the surface to matter for building and buying. A property inside one is in a historical coal mining area, and a CON29M Coal Mining Report is recommended before exchange. The report covers shallow coal workings, mine entries, recorded subsidence and coal mining hazards.

For conveyancers:

1. At the pre-contract stage, check whether the property falls inside the coalfield and a high risk area.
2. If it does, order the CON29M (most search packs include it).
3. Pass the result to the buyer and the lender: many lenders ask for the CON29M on a property in a high risk area.

The boundary data is free under the Open Government Licence. It covers coal only: tin in Cornwall, lead in Derbyshire and other mining need their own searches.

Certaby's property checks show whether a property is outside the coalfield, in it at low risk, or in a high risk area where a CON29M is recommended.

Source: The Coal Authority

Last updated 27 October 2026.