I am using left over scraps form my coop to build my external nest boxes. I have enough for the interior of the box to be 48 inches by about 14 inches deep. I plan to slope it from about 15 inches tall in the front to 12 inches tall at the back. I am starting with 8-10 hens. I could go with three boxes 16 inches wide or four boxes that are each 12 inches wide. Curious if three nest boxes would be enough? My coop is 48 square feet so 12 hens would be them most it would ever have.