We are looking at building a decent sized chicken coop to house broiler chickens. We live in the pacific northwest and get a lot of rain and colder days, and milder winters(except for this past winter). We are wondering how to insulate this coop. Should we use spray foam? My biggest concern is mites! We had a HUGE infestation last year in a different barn and I never ever want to deal with that again! I don't want to put up spray foam insulation only to have the mites burry inside and I've got to pick it all out just to get rid of the suckers! Our plan is to do a concrete floor with 2 ft tall walls with a wooden framed structure. Our walls and roof would be made of corrugated sheet metal. As we will have chicks in there at all times of the year we need to make sure that we are keeping some of the heat inside the coop over the winter. Thank you for your expertise!