A When it’s a house.
A number of London boroughs have housing policies which seek to resist the conversion of family housing to flats in order to provide choice and meet housing need. An inspector allowing an appeal against the refusal of permission for the conversion of a six-bedroom semi-detached house in southeast London to three flats appears to have used some rather shaky logic (DCS Number 400-012-949).
A local plan policy defines a family house as having three or more bedrooms, he recorded. The aim of the policy is clearly to retain family houses which are seen as a valuable resource, he reasoned. The proposed three bedroom flat on the ground floor would provide a family house in accordance with this definition and as such the proposal would retain a valuable single family house, he concluded.
Hmm. Bats can fly. Creatures that fly are birds. Therefore, bats are birds.
The following DCP chapter is relevant: 11.1321