I live on the upper gulf of mexico so cold is rarely a problem, heat is more of an issue. I'm building a new coop and will include ventalation. I know the rule of thumb is four sq ft per bird in the coop. I don't have any roosters and they have access to a protected run all day and a few hours free range on half an acre most days. I was planning to build a 4x8 coop with a 12x12 run. The run is mostly shaded under oak trees. Taking into consideration the climate here, no roosters, and no raising of chicks, how many hens will safely live in the coop? They will never be locked in the coop.