This is the interior of our 8 x 8 x 8 coop. It is where the birds sleep at night. They have a humongous nest box condo in there too on the left, 3 levels of 5 boxes each, meaning 15 boxes, but we only have 17 chicks and 9 adults. However, we are building the nest boxes to consider future birds which is why there is so many.
We use pine shavings for the floor, and hopefully it won't be too hard to remove and clean litter. If it is, we might need to install linoleum or something on the bottom to make life easier.
On the right, we put up 4 levels of perches staggering them one feet off each other. Books and others advice putting all the perches on the same level, but we find that a bit of a waste of space, and we just wanted to try it out now and see how it turns out. So far, the plymouth rocks and dutch bantam hen likes to all perch on the highest one, but I think in future when my cochin bantams grow up and move into this house, they might perch lower. We'll see, and we plan to learn by trial and error.
There is a door hidden in the photo next to the nest boxes that goes to the sheltered enclosed run. They also have extra perches there and space to have dirt baths and food and water.