I'd add a decal texture and some decals to break up the repetativeness of it; also more dramatic lighting for the final image will help. Looks good so far, pretty clean and good use of texture layouts.
Had a little extra time to throw at this over the weekend, so here is what I came up with. Took the suggestions about dirt and went back over the textures for the window frames, doors, and balconies. I also changed the brick texture and the top of the building detailing. As far as modeling goes, I moved the windows over. I…