So, as promised, here are the plans I drew up for submission to the local council, which these days are subject to strict criteria which last time I managed to 'wing'. So the plans all have to be drawn to an approved scale, here is 1:50 at A0. Also required is a Location Plan at 1:1250 and a Block Plan at 1:500, which last time I submitted plans I used the land registry document, but you aren't allowed to do that and have to buy them in, so that added about £25 to the cost. £206 for planning permission and then a further £30 service charge for using the central planning portal (which you can't usually avoid as the council don't accept them any other way).
So the waiting now begins to see whether they pass straight through, or not.
Whilst I'm waiting for this, I'll get the additions and technical details put on these drawings for Building Control approval...and I've got a new Kitchen to install into the new Kitchen extension (which isn't really new anymore, its 10years old!) ready so I can remove and re-route the external drainage pipes to make way for the foundations to do in for the extension.