ahhh i see, i would worry about this also. and I wouldn't do it either, have you got a shed they can go in during the winter months, Piggies hutches really should be in a shed or unused garage during the winter months, if we are cold outside the piggies will be too.Thet are quite sensitive to the cold. i know there are a few people on the forum who do keep them out all year round, but personally i wouldn't. I still worry that they are still too cold in the shed LOL ;D