I'm getting ready to put nest boxes in the coop! I have 10 EE, 5 NN and 5 BR. I would like your opinions on size, would it be OK to make them 14 inches wide and 12 inches deep or is that too big? There is a 14 inch spread between the studs and I think that I can find milk crates that are exactly that size, that way I would be able to attach them to the studs and not just the back wall. Also, how close should I put the roost pole in front of the nest box for the hens to jump up onto? From what I have read, it seems the correct height is somewhere around 20-24 inches from the floor, is this correct?