Hi guys,
I have chickens and ducks living together, 6 chickens and 4 Khaki Campbell. The coop is raised up and the chickens go in at night with a timed light (to keep them laying egg ;-) and some extra warmth) that leaves the ducks below in an area that is secured by fencing and during the winter it is sealed wit sheets of plastic roofing material, a little extra insulation and, most importantly windproof! Along the inner perimeter I have hay bales lined up, that seals it and insulates it nicely. The 2 Khaki Campbell girls sit on it once in a while and even lay eggs there. For really cold nights there is a dog igloo in it filled with shavings, it is mostly used for egg laying. Because the floor is just simple dirt (perfect for the dust baths) I do spread out, half of the area with a nice thick layer of hay. The area that hold the water heater and water container stays clear from hay. During the day I keep the door open enough for everyone to get out of the coop and catch some healthy sunlight. The hay in front is the hay that got to messy for the coop.
The ducks are more resilient than chickens but their little feet do get cold and I see how they prefer to stand on the hay and snuggle up in it. After all that talk: keep every one from cold winds and a accessible warm place to take a nap and warm up.
Here is the coop closed of with plastic roofing material
Everyone inside waiting for spring
I have chickens and ducks living together, 6 chickens and 4 Khaki Campbell. The coop is raised up and the chickens go in at night with a timed light (to keep them laying egg ;-) and some extra warmth) that leaves the ducks below in an area that is secured by fencing and during the winter it is sealed wit sheets of plastic roofing material, a little extra insulation and, most importantly windproof! Along the inner perimeter I have hay bales lined up, that seals it and insulates it nicely. The 2 Khaki Campbell girls sit on it once in a while and even lay eggs there. For really cold nights there is a dog igloo in it filled with shavings, it is mostly used for egg laying. Because the floor is just simple dirt (perfect for the dust baths) I do spread out, half of the area with a nice thick layer of hay. The area that hold the water heater and water container stays clear from hay. During the day I keep the door open enough for everyone to get out of the coop and catch some healthy sunlight. The hay in front is the hay that got to messy for the coop.
The ducks are more resilient than chickens but their little feet do get cold and I see how they prefer to stand on the hay and snuggle up in it. After all that talk: keep every one from cold winds and a accessible warm place to take a nap and warm up.
Here is the coop closed of with plastic roofing material
Everyone inside waiting for spring
I have to say, you are doing well with your ducks and chickens. Better than me. 
I have been wanting to get some hay on the floor and stuff.... it's just so expensive these days. Sounds like your ducks and chickens are happy! I have eight chickens and six ducks. I have a medium sized coop and a run outside. My coop doesn't have insulation or any of that fancy stuff.... but they seem OK. 
