Ooops, I should have read everyone elses' posts before putting mine in which turns out to be a repeat of all the others. One other thing I thought of was that they may roost on that internal roof and poop that all up, I wonder if you enclose the end of the pen and then roof the very top, maybe removing that lower roof?
Also what could become a pain in the butt for you is the wire all across the floor of the pen. After a long time, the poop will build and the wire will make it just a pain to rake the poo out. You may be better off laying the wire on the ground all Outside the pen rather than inside so critters will find it hard to start any holes on the outside of the pen and you could then rake the poo inside easily.
One more factor about a solid wire floor for living on, all chickens love to scratch. You may have ripped toenails on your girls if they catch a nail on that wire. I don't know if that could be easy for them to do but it is VERY painful for them since there is a blood vein in each toenail. One of my chickens ripped out a nail somehow running around the yard and stood like a pirate for WEEKS!
Aren't chickens the coolest things ever for making our minds just continue to come up with idea after idea after idea? I made THREE good size nest boxes out of 1 piece of cheap 4X8 plyboard and they are solid as rocks since the backs of each nest are actually the barn walls! Then the sides are screwed right into the wall studs. My chickens have made me into a pure genius! LOL I did cheat a little and used some scrap board for one floor and one of the roofs. But all my scrap was free at my local hardware store out of their free recycle/scrap bin.