im adding to my flock 39 chicks.. well little less when I get some family to take some bantams after they arrive. I have plans to clean out my coop and sanitize it again the month before they arrive. I want to house them in one side of my coop and allow them access to a sectioned off area of the existing pen its a 50x40, inside coop I plan to just use small wire that will not allow much of a beak to go into it but give the ability to view each other from inside. divide my coop in half its 12x4 with six nests boxes but right now only the first three are used by them, three perch bars at descending levels over 8ft leaving a little empty space (I plan to use for a water and feed area for the chicks). I currently have 13 laying hens occupying this right now. and after @ 1: or 2: they are allowed to free range that way most my eggs are deposited there at the coop.
how much of the 50 x40 pen should be set aside for a growing bunch of hens? and will that half a coop be enough or will I need to add onto my chicken condo.. as husband calls it.

how much of the 50 x40 pen should be set aside for a growing bunch of hens? and will that half a coop be enough or will I need to add onto my chicken condo.. as husband calls it.