i've got 2 coops, 1 on each end of the run... 1 is a 5x6 the other is an 8x8,,,, so 30 sq. ft. and 64 sq. ft.......at the moment i've got 13 birds that only use the small coop,,, so not quite 2.5 sq ft per bird.... i used to have 18 birds,, 16 of them would use the small coop and 2 would use the bigger coop...... they have access to both coops 24/7.... they choose to pack into the smaller coop.... they do have a big run and also use both coops in the daytime..... so my point is, they seem pretty happy with 2.5 sq ft per bird because thats what they choose to do!!!!!!!