Is your house a listed building?

Where this comes from, and what it cannot tell you

planning.data.gov.uk, published by the Ministry of Housing, Communities and Local Government under the Open Government Licence. Areas are matched by testing whether your postcode falls inside the published boundary — not by proximity to its centre — against all 1,573,900 live postcodes in England and Wales.

Some designations are too small to contain a postcode centroid at all; those are placed against the nearest postcode and marked nearby rather than presented as covering you. This is a signpost, not a legal search. Confirm with the local planning authority before doing anything that depends on it.