I love peonies (Pfingstrosen). They bloom in late May, early June. But I just found out you can keep them for 6 months in your refrigerator. You have to cut long stems of the flowers when they are still buds. Wrap them in newspaper. Then keep them in the refrigerator until you want to use them. Bring them out, put them in water and you have peonies out of season. I'm trying to win a small refrigerator on eBay. I want to have them in September for my Anniversary.
Why not start with an IBC and cut a hole for the door? You could build closed laying boxes into it, and something for the chickens to roost on. Put some straw or saw dust on the floor. You could add vents to the side for air. If it sat inside a chicken run that you can walk into, the chickens could be safe, dry and happy. I have an extra IBC. Maybe this could be my chicken house? I bet I could even plant the outside of it with mud and grass for extra insulation and good looks.