Haha. Fair enough. Worth an ask though now the rules have been changed to 6m over the old 3m outwards to the rear.Yes, fair point, lends itself to a redesign of layout though, but that costs money of course.
p.s. If an extension to an extension to an extension is allowed as permitted development I'm a Chinaman
The house is in dire need of a lot of work regardless of the requirement to redesign it though so the added prospect of moving/removing some walls and doors is not so much of a big deal. It was more a case that if the likelihood of being able to fill the corner in was a high one the order in which our renovations takes places will change around while we wait for Plans etc to be drawn up.