Coop is an old uninsulated dog house. Approximately 2 1/2 feet wide by 5 feet in length but at least a foot of the length is used as a nesting box. There are 5 chickens, each a different breed. We live in Minnesota so it gets pretty cold. They are locked in the coop for almost 12 hours a night at this time of year. They made it through last winter in this coop but I am worried it is way to small and unhealthy for the birds.