If you don't mind sharing, how much did it cost to build your coop and run? I am looking for tips to keep the cost down as I am on a limited budget. I plan on having 4 hens, it needs to be cold weather proof down to minus 40. One thing I would like to do is build my coop right up against the house, where there's a basement window, and have an opening so that I could open the basement window when it's really cold and heat the coop that way. Is that a dumb idea?