After reading a lot about coop design, I'm still left with plenty of questions. I'm hoping that some of you experienced chicken keepers can help me out. First, I noticed the frequent advise on adequate ventilation. This is never accompanied by any detailed explanations. I live in a cold climate. The more you ventilate in the winter, the colder the coop will be. Also, if well ventilated, what good is it to insulate the walls? If I greatly reduce ventilation in the winter, then ammonia fumes and humidity will build up in the coop. Are there any guidelines for the number of square inches of ventilation per bird, or per square foot of coop, in winter? How durable is a plywood floor? I don't want something that prematurely deteriorates while the rest of the coop is in good shape. Is some type of vinyl flooring recommended or is a good durable paint (sealer) adequate? I see lots of 8' tall coops. I'm guessing they are made this high for the ease of human entry. It seems I'm always reading about nest boxes and roosts being placed at a low level. Isn't the high ceiling height making those more difficult to keep warm in the winter? I plan on keeping only 6-8 hens, and it would seem far easier to keep it warm in the winter, if the ceiling height was with a couple feet of the roosts. Are there other reasons why a high ceiling is desirable?