Ventilation

Ammonia from droppings is more dangerous in cold weather than the cold itself. Provide 1 sq ft of vent area per 10 sq ft of coop floor, high on the walls under the eaves so air moves above the birds without creating a draft on the roost. Hardware-cloth-covered soffit vents on opposite walls give cross-flow. Birds tolerate cold far better than wet — wet feathers from condensation cause frostbite, not the temperature alone.