Glossary
D
Derived or weathered flint
Flint found already free from its chalk matrix (cf virgin flint). Can be obtained from fields, riverbeds, beaches or gravel pits.
Designated heritage asset (for heritage policy)
A World Heritage Site, Scheduled Monument, Listed Building, Protected Wreck Site, Registered Park and Garden, Registered Battlefield or Conservation Area designated under the relevant legislation (as defined in the National Planning Policy Framework 2012).
Dormer window
An upright window, usually with its own roof, that is built into a pitched roof and lights a room within it.
Double-lap
The overlap formed by the tail of a tile or slate lying over two courses below.