We're planning a flat roof single storey extension to a bungalow. It's out the back and as far as I can tell, going by the checklists available, is perfectly in line with the permitted development rules.
However, our planning dept have stated that as we were looking to use our garage wall to form one of the external walls, it would require planning permission. Otherwise, the position and dimensions of the extension are fine.
My question is, if I were to build a wall next to the garage wall, how far away would it need to be, to be deemed OK for permitted development? Would it need to be a minimal air gap, i.e. 150mm, or are we talking 1000mm? Planning dept are really slow in returning messages and would like some idea of what to do, and potential resolutions that don't involve the council planning dept getting involved.
Thanks in advance