My wife & I are newbies at raising chickens. We got (9) Leghorn chicks in early October '15. They are now over 3 months old now. I converted a storage shed (4' H x 3.5' W x 4' L) into a bi-level coop. Each level of the coop has over 12 square feet, over 24 square feet overall, with room for 6 nesting boxes that I still need to build. The "run" area is a spacious 75 square feet. I have three extra chickens I need to offload! I know that within 2 months they'll start laying.
We live in the desert south of Blythe, California, near the Colorado River and Arizona.