We had this building built for us, it is a 10' x 8' building and the run is a 10' x 20'....we are going to be extending it soon to a 30' x 20'
the features in the building are...a 10 foot ridge vent for extra ventilation, 2 standard size windows, and a 12'' x 12'' chicken door, and then we added the plank going down to the ground, and the roost and we will add the nest boxes in a couple of months when they are closer to laying age. we also added screen doors that way in hot weather we could open the front doors for even more ventilation and air flow to keep it cool in there we also insulated the ceiling and later we are going to insulate the walls.
we attached the brooder box to the wall because we thought that way the older ones would not roost on it...well they still do but another good thing about having it on the wall is the chickens that are out of the brooders and in the coop dont loose any floor space.
here is the roost...we used to have it on hinges where we could raise it up and clean under it but after about 2 weeks after they started using the roost we knew we would need to clean it every time we clean the coop...so we bought some heavy duty hooks and eyes and now we have it where we can easily take it out and scrub it down