I'm about to build my first chicken coop, and I'm having trouble figuring out to balance chickens' needs for no drafts but plenty of ventilation. I live in Montana, so the cold is a serious concern. We hit negative 30 this winter with wind chill. I'm getting white rocks, which I hear are decently cold hardy and am planning to build a basic lean to coop that would attach to my run. Should I insulate it? It's a lot more work and summers here can get hot (90+). Do chickens require ventilation overnight, or would a few windows I could open during the day be enough? If they require continuous ventilation, where on the coop would be a good location? I can't put it on the south side, because that's one of the directions we get wind from but I could do the east side. Should the ventilation holes be high or low? Should I build the coop on the small side, so they can better take advantage of each other's warmth? I really appreciate any suggestions. Thanks!