Welcome ColoradoPeeps! The general rule of thumb I use is 4 square feet of coop space per large fowl adult, 10 square feet of run space per large fowl adult. A little less will usually be okay as long as your chickens get along well. Mine do not spend many days inside the coop even in the coldest part of winter. I can count on one hand the number of days I didn't see them come out more than a few minutes for a drink of water. There have been a couple of long blizzards during which I put the heated waterer inside the coop to ensure all had sufficient water, but only a days or two at most, they make too much of a mess with it and they really want to be outside whenever possible. My large fowl coop is 4x8, they have a 10x14 foot run, and are permitted to free range almost every day for at least a few hours, up to most of the day if it's the weekend and I'm there to keep an eye on them. I currently have 10 birds in there, so I'm stretching it a little, but they all get along well, and 6 are pullets that are just approaching point of lay. I expect to reduce by a couple as winter approaches, especially if I see them starting to squabble. If they don't, and if all produce better than they are, then I may just leave well enough alone in case I lose a couple, which happens from time to time, whether reproductive issue, injury, predator, or illness.
If you have bantams the space requirements are, I don't know, a third less, possibly as little as half, depending on size and activity level as well as compatibility.
Hope this helped
If you have bantams the space requirements are, I don't know, a third less, possibly as little as half, depending on size and activity level as well as compatibility.
Hope this helped