I have an 8 X 12 coop with a small run and I have 19 chickens in there. 1 roo that isn't doing his job and 18 hens, 4 are still juvies. I have 12, 7 week old chicks roaming the north lawn and roosting up in a dog kennel at night. (7 pullets 5 roos) 3 of those roos will go to freezer camp in 8 weeks, I'll probably end up selling my beautiful Speckled Sussex roo and then I have a pair of Golden Cuckoo Marans that I'm keeping. DS #2 just finished building me two breeding pens... north half of the pens are half way opened with chicken wire, south ends w/ nests are enclosed. Both pens are almost identical mirror images of one another and are 4.5' high and 10' X 4' have a long roost on one side and three nest boxes on the other that I can access from the outside. They both sit on concrete, (should make easy cleaning with a hose). My wife thinks it's going to permanantly stain the cement. Neither have attached runs. How many birds do you think I can put into these... so that they aren't too crowded. 5? 8?