Yes, and those prefab deals - vastly overestimate how many can fit there.
A couple of solutions:
Add more clutter, you are wasting the vertical space, your birds can see every other bird nearly 100% of the time
add ladders, sawhorses, pallets up on blocks, leaned against the wall,
Put all your birds in pin less peepers - that should stop the feather picking
examine your birds for mites just to make sure
reduce the size of the flock, which is easier and cheaper than adding more space, but that is also an option. If you go this route I would still add the peepers, because feather picking can be a hard habit to break, even if you get rid of the overcrowding.
I would also, take a head count and know, that regardless of feet or inches and what everyone says... you KNOW that this many chickens does not do well in this much space.