The Town and Country Planning (General Permitted Development) (England) Order 2015

Condition
This section has no associated Explanatory Memorandum

A.2  Except for development also falling within Class A(a), Class A(b) development is permitted subject to the condition that any structure erected in accordance with that permission is removed at the expiry of a period of 6 months (or such longer period as the local planning authority may agree in writing) from the date on which work to erect the structure was begun.