QBD 12 March 1991. The second respondent, N, was occupier of a mid-terrace house, extended to the rear, creating a flat roof on which had been erected a parapet wall a metre high. An enforcement notice was served in respect of the wall. On appeal against the notice the inspector found that the development comprised enlargement of the dwelling and alteration of its roof. It therefore fell to be assessed under the General Development Order 1988 Sched 2 Part 1 Class B. He held that there was no breach of planning control since erection of the wall fell within permitted development. The council appealed. To be an enlargement of a dwelling house there must be an increase in the volume of usable space within the dwelling rather than it being made to appear larger from the outside. Appeal dismissed on the grounds that the correct approach was to proceed on the external appearance of the house. Planning restrictions were to do with external appearances and not on internal practicalities or r