Loft extension and double story planning permission

[Sunil1995]

Hi,

I bought a house with planning approved in the attached architect drawing. The permission is for a 4m extension, full width on the single story and half width on the second story, and is shown by the red brickwork in the attachment. This will also involve the new roof above it.

I would like to create a loft extension at the same time with a hip to gable roof on the existing part of the house and a dormer over the part of the house which isn't being extended (i.e. the proposed roof line will remain the same).

Will I need planning permission for the loft, as I assume it will be going over permitted development. If so, is it better to reapply for the permission including a loft extension, or is there any other work around?

Thanks!

Proposed Elevation, Section and Roof Plans.pdf