Is it possible to put in a request under Permitted Development for a dormer whilst planning request has already been granted for single storey rear ground floor extension?

 

I dont know whether the council will require the first project to be completed (the rear extension)  before the second can start (dormer)?

 

Thanks

No reason at all why you can't make an application for a certificate of lawful development for a PD extension to the roof of the dwelling despite having an extant approval for a ground floor extension. The limit on volume created relates to the roof of the building not the building as a whole. The two issues are completely separate.

 

Of course you are not obliged to obtain a certificate before carrying out PD works as long as you are confident you comply fully with the provisions of Part B in Schedule 2 of the PD rules.