pete & mark:
build is in the eye of the beholder. thats the beauty. as long as its a "barn" you're in the clear. heck could be a train barn!
i plan on roughing mine up a bit too. one of the advantages to scratchbuilding as opposed to kits or preassembled buildings. not knocking them, just pointing out the obvious
and no worries on time ... its starting thats the important part.