I have made a small pen to raise chickens in until they are big enough to go in with the "big chickens". The pen is 25 sq. ft. It will not be a permanent home, they will stay in it just til they reach their adult size. I am putting a small dog house Inside the pen but they shouldn't use it that much because they won't be in the pen til April and the coldest it has ever been in April here is 63 degrees (and that was in 1928). How many chickens could I fit in there. They will probably be let out maybe 30 minutes a day to walk and scratch about.