Is a dormer enlargement on an extension roof permitted development?

30 Mar 2023
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United Kingdom
I've recently been granted planning permission to build a first floor extension with a pitched roof about half the width of the existing ground floor extension, to the rear of the house. alongside this I intend to have the hipped roof converted to a gable end and a dormer conversion done to form a new bedroom.

The permitted development technical guidance states:
"The enlarged part of the roof may join the original roof to the roof of a rear or side extension (generally referred to as an ‘L-shaped dormer’ on a main roof and ‘outrigger’ or ‘back addition’ roof), whether the part of the house being extended forms part of the original house or is an enlargement, or the shape or level of the pitch of the roofs are different in relation to each other".

Does this mean that continuing the dormer on to the new extension roof to form an L shaped dormer is permitted development?
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