Obvious solution would be to make a corridor around bedroom 2 to have separate access to bedroom 3. B2 only window would prevent a corridor going across the room. This would make B2 alot smaller and create wasted space.
Other option I can think of is to remove part of the wall between B2 and B1, making B2 a long bedroom using half of the window of B1. B1 would also be smaller and a window could be added in current cupboard space. Then small corridor across. Imagine this would cost a decent amount.
House is semi-detached with the detached side stairs side.
Help/opinions please.