Two schools of thought in my mind.... stationary or mobile coop. Each has it's own perks and drawbacks. See my profile photo for my idea of an ideal stationary coop: 8x8x6 to the bottom of the rafters, interior laying/brooding boxes, and a gradually ascending perch system allowing the birds...
I am looking for Dominiques in lower Michigan, I realize this thread is dated, just wanted to mention it if you decide to keep or raise them again. Thanks!