The 2nd story space in my coop is generally used by those chickens lower on the pecking order. They have a space to get away from the other chickens instead of being chased around by other birds when they get too close. Is my coop too crowded? No, they have 10.5 sqft per bird and have access...
You could split the vertical space on the far end of the coop. Make a 4x4 area that splits the 7 ft space in half. An option could be to put all the roosts over the 4x4 space and use it as a droppings board. The lower half of the 4x4 space would be extra room for your hens without a pile of...