Many thanks Woody.
She wants to proceed quite quickly (and the council are very slow) so will move forward without an LDC if it should meet all PD requirements; which it appears it does.
Re: chimney, this will be as shorter than in image above. I think 0.99 should be fine for building/flue regs.
I have been through the existing (flat roof) LDC and these appear to be the key PD questions; I can't see any reason why any of the answers change by adding a Crown Roof (as per image in OP).
Hi,
I my trying to help my mother who wants to do a rear extension under PD.
She has an CoL for an extension with a flat roof; but now wants to proceed with a pitched/crown roof.
She would like something similar to image below: proposed extension in Blue; proposed roof in Red; proposed flue in...