Don't forget that for buildings much over two stories high, you need to tie the opposite outside walls together with something, if outside buttresses are not going to be used. Many older buildings in the US have 1/2" rods extending from side to side of the buildings, threaded on the extreme ends, with a nut and large pressure plate, to tie the two sides of the building together. These ties are placed every 6 - 12 inches along the outside of the wide side of the building, and keep the weight of the bricks above from bowing the wall, and then collapsing the wall (outwaards)completely.

Dave