One of my objectives is a substantial gatehouse. So my plan is for CBS 4x4 towers either side of the gatehouse fronted by half a 4 " tower. The CBS part can either be from any existing CBS stone buildings you have or the Square Castle Tower add on. Height is down to you - personally I go big an...

Great post and hopefully will put this issue to bed
Unless you do KS1 and 2 add-ons ............

The outside tower pieces will allow 180 as you have 1/2 circumference piece and 1/4 piece.
You will however have a door problem as you currently have 2 doors on the same piece for right angled walls.
The internals will give a problem as you have pacman pieces ie a 90 cutout for right angled.