I suppose it depends how far you want to walk.
What is more important to you - a toilet next to the garden or an open plan k/d/l?
Let me know what you need and I’ll take a look.
Your BCO isn't turning a blind eye at all. All he's doing is making the study part of the overall open plan Kitchen/Living/Dining - removing the "Inner Room". Same goes for the Living Room - remove the door and you're home in a boat.
You have inner rooms which need an alternative means of escape.
I am also surprised he didn't ask for a sprinkler mist system in the Kitchen. The stairs coming into the Kitchen is dangerous.
Thought this was a philosophical question about needing Building Control and Building Regulations - pity.
However - yes this will require an application.
Where do you:
Park you car.
Put your bins - so you get them out.
Put your washing line.
Put your fuel storage.
How will you get large items from the front to the back - hot tub, gazebo, obligatory motorbike, ride on lawn mower.