Ok Ive been making a barn in max, but since i couldn't find the barn texture I just used cement, and it could be a weapons storage area. Its enterable, has 2 levels, couple rooms, and 2 doors to the outside.
http://files.filefront.com/Barnmax/;8624460;/fileinfo.html
Probably horrible with poly count and efficiency, but feel free to use it however you want, modify, critize, flame me

I just know that Im a beast at Boolean.