It's getting colder here and I am starting to think about how I am going to winterize my coop this year. I have mostly Silkies and 1 Cochin hen in there. I understand the need for ventilation, the coop is roughly 8ft x 4ft, and has 2 windows about 1ft x 1ft, 1 in the front and 1 on the back. I was thinking about putting plastic over the front facing window, because that gets the most wind, and leaving the back open.On nights or days when it is very cold maybe I could temporarily cover the back window, or partially cover it..? Or, would it work if I put some sort of breathable fabric, maybe like loose burlap over the windows? I had the burlap idea because I was thinking that if the window were left open, snow would get into the coop. I do not want to put a heat lamp in the coop because we are prone to loosing power in the winter and we do not have a generator. I don't want them to be accustomed to the heat and then loose it all of a sudden in a big snow storm. We are at the top of a big hill without many trees, so the wind chill can make things much colder up here, what are you thoughts? Thanks in advance!