Frame, chicken wire, walls, floor, roosts, nesting box, heat lamp, and access doors (wheels, if you want it mobile)
It is easy and beyond beneficial to raise your own hens.
Compost eater and producer
Bug and weed killer
The chickens eat the compost and turn it directly into usable compost that they till into the ground all within a matter of hours. Also while they are weeding, what a great pet!!!!!!!!
My coop has 10 hens and 2 roosters which you would think would be too much for my tiny coop but it's not. All the hens huddle on the roosts together and use the same nesting boxes. No room is needed because the hens would not use it. I move my coop daily, slowly so I don't run over my pets.
The picture above they are out which they usually are not. My yard is not chicken proof which I learned the hard way. There are more pictures of the coop here.
I built a pen out of pallets to wheel the coop up to so the chickens could have a semi permanent location. I move this pen once a month and the grass always grows back.