I was told by someone that it is important to consider drift capacities when doing a seismic evaluation. Particularly for things like unreinforced masonry and stuff like that. As they explained it to me, if you have something like a masonry wall which is not being used as part of the seismic force resisting system, it still has to be able to move along with the building without failing - even if it is just going along for the ride. Makes sense to me. They told me to look in ASCE 41 for drift limits for different materials. I'm reading through it right now, and I can't find anywhere that even mentions drift capacity. Can someone please tell me if it is actually in there somewhere. In particular, I am looking for masonry walls. Thanks a lot.