We have 3 super large coops and 3 small coops plus 9000 sq ft run that has part of the woods in it.1) We did our homework, sorta.
2)We went about middle of the road.
3) we enlarged our coop after we designed it. Originally approx 8' x 8' ballpark; final footprint: 10' x 14' and a tapered roofline for 80% ceiling west side(of the 14' length) vents.
4) put run under the same metal roof. Current total footprint? ~18' wide x ~20-something feet.
Everyone does their own thing, but I’ve seen people buy those coops at TSC and shove 6+ when it fits maybe 3 full sized. I have 3 bantams in a free one we got, but they’re moving to our newest big coop. The grow out quail will be using that coop next.