My husband and I built a coop for our Roo and 2 girls. Most of my questions have been answered here, except for 1. We live in MT, it can get pretty cold. Sometimes in the negative teens, tho not often and not for long. My question is, how much ventilation is too much? I know they need it to keep the frostbite away but I can't find anywhere where it tells you how much is too much. Here are pics of what we ended up with. I was so oncerned about ventilation that I did way too much for winter. We have since, closed some of it off and added eaves to the open areas and I also lowered the front roost bar so that our roo, who grew to be massive, was below the window opening. Is there anything that tells you that the air flow should be so much distance above the top of the head? We have 18 more chicks (6 weeks today), that we are going to add, I'm hoping before the winter really sets in, and we are going to build a "hotel" to go along with the theme, as well as adding more roosting spots for the little ones but I'm not sure if we need to cover up more of the top venting. The windows are all covered with plexiglass and weather stripping. I don't have a pic of him on the roost, I will try to get one in the morning but I am usually letting them out and closing them in when it's dark out. This shows the large upper area I am concerned about. Other side This is just cute with my kids checking out the birds checking it out The roost in the front, at the 2 windows, has been lowered to about 1/2 way between the upper and lower window Front view The finished version. I will add another pic showing where we added the eave and a small "flop-down" thingy (very technical) to block out wind and snow.