Yes they are, but it is also not legal to put them up in most towns and cities. There are also restrictions on how the roof needs to be reinforced to handle a specific snow load. If a guy intends to insolate a pole barn, its cheaper to build a metal building or even a "stick built" garage here. Any bare bones just outer shell 30 x 40 building erected on a prepared sight around here is easily 2x the price he was quoted.