I've been able to reuse a house that I made for turkeys several years ago, for my pared down flock of 6 EE hens. It's got a wooden pallet as the base, so it's ~3 1/2' x 4' and 4' high. There is a trimmed, old rubber 1/4" thick rubber mat as the floor which insulates. (The excess sits in front center on top of a cement cinder block and creates a ramp.) I fixed the leaky roof and I added a door on hinges, which opens to the east. The building sits about 5 ft. south of a garage sized building which blocks all due north winds. It is all wood, no windows, with a 10" high curved access "door" bottom middle of the door, which hooks on the top and bottom RH side. I left staggered gaps on top, so the air has to go under, then over, and it doesn't create a draft, just air exchange. The coop is enclosed in a 12' square dog fencing.
I have a heavy board to put in front of their door, when necessary. I used it to train some of my 6 hens who were roosting at night on the roof. I fixed their bad habit and now all the hens roost at night on the 8 inch high roost I made with two horizontals made from old, wooden wheelbarrow handles and supported by 2 x 8's. Not high, but high enough. (I sanded them before using.)
I clean every other day, but it remains dry and smells great. I use pine shavings covering Equine Fresh dried pine pellets under the roost, to pull humidity. They REALLY work. I use them for my horse's stalls, too. I also have two nesting boxes with straw, but they are fighting to use their own home made nest in the corner. No matter. Sometimes they use the nests.
I still need to cover two cracks with a couple of 1/4" plywood pieces this weekend.
I have a large canvas tarp ready to cover the coop first real snow. I have seen what happens to this house in a snowstorm.
Canvas is what large chicken operations use. It allows for airflow but it blocks the snow from coming in without holding in humidity.
MY only problem is that until I fix those cracks I sometimes get frozen eggs!
My girls are fluffy, active and LOUD.
I also have a light on a timer and I keep their water outside, in a heated dog water bowl.
I get 3-5 eggs/day from them.
