The issue of the planning unit comes up not infrequently, particularly in enforcement cases. As an inspector has recorded and helpfully set out in his decision (DCS Number 400-016-723), the classic definition is found in Burdle v Secretary of State for the Environment . Readers might find it useful to keep this somewhere handy.
The court held there were three issues to consider:
“First, that whenever it is possible to recognise a single main purpose of the occupier’s use of his land to which secondary activities are incidental or ancillary, the whole unit of occupation should be considered … But, secondly, it may equally be apt to consider the entire unit of occupation even though the occupier carries on a variety of activities and it is not possible to say that one is incidental or ancillary to another. This is well settled in the case of a composite use where the component activities fluctuate in their intensity from time to time but the different activities are not confined within separate and physically distinct areas of land. Thirdly, however, it may frequently occur that within a single unit of occupation two or more physically separate and distinct areas are occupied for substantially different and unrelated purposes. In such a case each area used for a different main purpose (together with its incidental and ancillary activities) ought to be considered as a separate planning unit.”
An oldie but a goodie.
The following DCP section is relevant: 4.324