My wife and I are new to this whole chicken thing and we just got 26 chicks (23 buff orpington pullets, 2 BO roos, and one unknown "free rare chick" we get to guess at). They are a week old now and we haven't lost any. We have an old kiddie pool set up as their brooder in a spare bedroom. Our coop construction is getting underway. We are converting an old shed attached to our garage. The shed is plenty big enough for 26 birds and my concern is that it is too big for them to stay warm in the winter. I live in southern New Jersey where our worst night temps occasionally drop into the single digits but is usually in the teens- twenty's (F). My initial plan was to put up a wall to give them an area about 10' x 13' but I was wondering if it would be feasable to leave all the space for them (about 20' x 13') and still keep them warm. Is there a "maximum space limit" per bird?