Had to add space vertically to my coop for some new additions and minimize the mess for winter months when the chickens would be going out less. (It gets pretty cold in Michigan some times). l saw a post where there were bins below the roosts and decided to try pull out bins with sand in them. They work EXCELLENT! The sand absorbs the smell and dries out the poop really well. I got the bins at the local home improvement store in the cement section for about $6 each. They are 24" x 28". They make bigger ones as well. I had to reinforce the lips on the ones that had the longer span with wood strips, and/or dowel rod because they were bending and falling down. They work great now. I keep about 1/2" of sand in them and I pull them down and sift it with a plastic feed scoop that has a bunch of 1/4" holes drilled all around. If your lungs are sensitive wear a mask because sometimes it does create dust in the air. Eventually I would like to create a sifter that fits in a 5 gallon bucket so I can just dump it in for faster cleaning. I think there would be less dust too.
I love this plastic pet-fence. It is 5 ft x 100 (I have 2 of them) Tenax pet fence pro. There are different grades and sizes. Got it on amazon. Just pop up the stakes and move it easily when needed. Zip tie to the poles and stake at the bottom every so often. I usually still lock them up at night just in case. nothing has tried to chew through or dig under yet. Some say they could fly out but they have never tried in the last 6 months. My lightweight leghorn did fly in once when she was locked out. I let them free range quite often. They are spoiled.
The floor is vinyl so it cleans up with a hose and scrub broom.There is a hinged flap so I can rinse it out the back.
If you have an external nest box it is way easier to gather the eggs if it hinges down.
They started laying eggs in the sand so I put up a curtain to darken up their nest boxes and it worked.
There is a double roost above this one with about 6" between.
On these 3 I reinforced the edges that ride on the wood tracks.
The darn things like to sleep on my storage shelf so I let them.
And my freshly painted coop will never be this clean again lol!
In the winter I put an adjustable flap over the vent. Last year a couple got frost bite on their combs.
PS. The babies in the little pen are big girls now and have integrated well by being nearby but safe until the big girls got used to them.