I have three next boxes in the other coop and am hoping (keeping fingers crossed) that the new hens will use those as well. If I find I need one or two in the new one I will add them, by cutting into the side and adding boxes that hang out the back, so as to not take up any floor space in the coop. I can certainly increase roost space, however.
Unfortunately, I cannot go taller due to the limited height of the roof of the current coop. In order to butt up against it, I have to keep this roof below the other. Unless I rethink my design of connecting the two and place them a couple of feet apart and connect them with a small "run" area. Then I can make the new coop taller and maybe put a piece of gutter on the current coop to keep the rain from falling directly into the small run portion and making a mess.
Tall enough to walk into would be the best, for you and for ventilation.
Here is a photo of the current set-up. The large blue building is my old coop, which has been turned into my step-daughter's bunny hutch when I decided to downsize. It was getting to be too much for me to keep clean. If I would have researched and found out about poop boards/drawers ahead of time I would have just made some minor adjustments and kept using it. The small blue coop is a TSC coop I purchased recently. It is fine for now, but will not be sufficient come winter if the chickens decide to spend more time in there. The chickens also have access to the underside of the large building. All-in-all there is 138 sq. ft. of run space, not including the 6x6 which will be under the new building. The square run space you see in front of the small building is a tractory-type portable build which will only be used to move the chickens around the yard once the new coop is built. So, really, I could just make a stand-up lean-to type shed without a run underneath, still have plenty of run space for the chickens, and be able to attach it to the small coop, the side where the portable run is right now.
