I am in the sticks with no limit on the number of poultry I can have, unless there are so many that it contributes to watershed damage. And even that is not spelled out. It is all very ambiguous. That being said, I have an 8x16 coop, and a 10 x 30 run, with a few areas (outside the run) shoveled out so the birds can walk around. I think I need fewer chickens in the coop when they refuse to go outdoors. Or I need less wimpy chickens.
I am very seriously trying to avoid chicken math, and the only chicks I will have this spring is to test out a broody/grow out area that I put in place last year. If one ends up hatching a brood of chicks, I will have to reduce the size of my adult flock. I will not build another coop, and the current coop is on a trailer and hard to make an addition.
What I need is a barn like yours with plenty of space for everyone to walk around.