A quick scan of the appeal record reveals any number of examples of arguments concerning what constitutes the side elevation of a dwelling. In dealing with an appeal against the refusal of a lawful development certificate for a two storey rear extension to a dwelling in south London (DCS Number 400-017-646), an inspector decided that a bay window in the rear elevation was part and parcel of the rear wall.
The house had a shallow trapezoid single storey bay window in the rear elevation, the inspector recorded. He noted that if the sides of the bay window were considered to be walls forming a side elevation of the original dwellinghouse the two storey rear extension would not comply with the limitations set out in Class A of Schedule 2 Part 1 of the GPDO. He acknowledged that the Government’s Technical Guidance states that a wall forming a side elevation of a house will be any wall that cannot be identified as being a front wall or a rear wall. Nevertheless, taking into account the very small projection, no more than 0.5m, the shallow angle of the side panels, the relatively flimsy construction and the single storey nature of the bay, he took the view that the bay window was merely a detail of the rear wall of the original dwellinghouse, as a matter of fact and degree. Therefore, the extension did not exceed the Class A limitations and hence would be development permitted by the GPDO.
Guidance concerning interpretation of the permitted development classes can be found at section 4.342 of DCP Online.