I have found information about the standard size for nest boxes. I am trying to design the nest box setup to attach to the outside of the coop and I can't figure out how big to make it. I realize bigger can be better, but I want to make sure that I make it big enough and then I can add inches were they are available. A lot of my pullets are heavy breed and will need space. Lots of it. I have Jersey Giants, Brahma, Easter Eggers, Wyandotte, Blue Andalusian, Welsummer, and Black Sex-link. Anyone have any practical experience with nest boxes for big girls? Plus-sized if you will. Pictures are great if you have them. Measurements are especially helpful.