Hello everyone! So, I am getting six chicks in June (I'm sooo excited!) and I was wondering how big the nest boxes should be. I am getting all large breed chickens (barred rock, cochin, brahma, delaware, EE, and golden laced wyandotte). I picked up a two shelf book shelf from Ocean State Job lot for $10 and I was hoping I could use that, but now I'm worried the spaces will be too small. I will be turning it on its side so instead of being on top of eachother the holes will be side by side. The dimensions of the each box will be 12" wide by 16.5" tall by 11.4" deep. What do you guys think? Thanks!