They just need a place to get out of the wind and damp. They will use the shelter from wind more than the shelter from damp. Although, my Swedish don't like to go out into the snow. They are wimps compared to the Appleyards.
You won't get any cold enough that they need protection from thh cold.
If you get snow, you will need a peaked roof with strong rafters to hold the weight of the snow. My duck house has engineered roof trusses for safety. If we get an unusual amount of heavy wet snow, I go out and rake snow off of roofs. However, my coop roof can support what is our normal snow load.
You'll be a lot happier in the long run if you can get inside the coop and stand fully upright.
My duck coop has "benches" for metal garbage cans full of feed. Ducks don't roost, so those stay clean. Ducks lay under the benches. Didn't think that out well. I have to get down on my knees to collect eggs.
Coop will need ventilation. Stale damp air can make your ducks sick.
Exhibition quality Blue Swedish Ducks and Gray Saddleback Pomeranian Geese, Hatching eggs available in late winter and spring. NPIP
Exhibition quality Blue Swedish Ducks and Gray Saddleback Pomeranian Geese, Hatching eggs available in late winter and spring. NPIP
