My ducks and geese were locked in a secure run at night and on nasty winter days with a lean-to last winter for protection. Mostly the lean-to protected their feed, because they weren't all that interested in it. lol This summer I built a simple A-frame with 7 2x4s and 2 pieces of 3/8" plywood. Simple enough I built it single-handed with my dad's nail gun, the chicken love it when I let them out to free range with the water birds, lol. They just need somewhere they *can* get out of the weather if it gets too nasty, and I lure them into the fenced enclosure with scratch or the promise of other food and have never had a single problem. They run into the enclosure as I get close to it, knowing dinner is in the offing. If you're concerned about predators, a dog kennel like structure is a good idea, but you'll need to get them trained soon so you aren't having to do it trudging through the snow.