wow 16 boxes??? Id go half that many--I have 12 girls in one and I only have 3 in there and they all fight over 1!
Some friends did an experiment and made different sized nest boxes. By far the girls liked the deeper cozy boxes best. Perhaps 14 or 15 wide and high and 18 deep. That would be cozy for them. My buffs like theirs. They enter through a hole that is about 10x10.
