They key is how do you keep their space clean? In commercial egg operations, the chickens live in mesh cages, and the chicken poop falls through the mesh cages, and they stay relatively clean.

If you're doing a house/coop, and you don't have an outside run, you'll need to clean the hut often- at least weekly - or it will fill up with chicken poop. Ideally you can have a coop/house with an attached fenced run. Then most of their excrement is left outside, and you have to clean less often.

I have a 6x12 foot house for my chickens with a 12x20' fenced run. It's good for 20-25 chickens.