Ben,
This is also an option, but the way this particular building is, the beams and columns supporting the building would be 24 feet high. Also, the bottom 12' of wall is a 12" thick concrete retaining wall and the top of the wall is an 8" masonry wall, there is a 4 " gap between the beams and columns. The columns would also be sticking out into the space which the client didn't want. So we began investigating the double wall option mentioned earlier.
Jeff