My DH did the research and built a great brooder for our 4 chicks. He CANNOT envision what 4 adult hens look like or how much space they need. Luckily we do have a formex snap lock coop to accommodate 6-8 hems and a 10 x 12 run plus free ranging. So I just shut up, he will figure it out before he needs to.
An adult hen can be thought of as a 15" cube -- the physical size of the chicken and a little personal space.
