I've been building our coop, more-a-less 2 coops in one. We have a corn crib that I've covered one 10x12 room into a coop with laying boxes and I've made a "doggy door" that is slide gate opening into what will be a 12x20 screened in coop. During the day the gate will be open and both coops usable. At nigh, we'll escort them in and shut the gate. My question is, how many chickens can we have and them not be over crowded?