thanks for replay, actually I didn't apply any UV into it, because the whole building is just one simple color without any line of noises, there is no way I can fix this uv's, the building is 20 floor and alot of tweaking and extruding faces/edges going on. so fixing this uv's is chaos,

what do you think guy about apply an sand texture into it? but there is some faces that has been stretched.

any option?