My girls have a main room of 32 square feet with a vestibule of 16 sq ft. I have either a surface or perch running around the perimeter to give them room to roost. At most I had 16 birds in there that would pretty much only be in there to sleep. I open them up every morning to roam around my property. In the summer, when I can get the gate to stay closed because there's no snow, I close them off into an approx 20'x50 pen area.