Back when I was building my shop, an old Iowa farmer friend said the scariest shop prediction I'd ever heard at the time. He said, "A man needs 12 feet a year on his shop building". The second scariest thing was the knowing chuckles and nods of the others there at the time. Twenty years later I know that he was right. True, I never got my extra 12 feet, but that didn't mean that I didn't need it.