Summarize:

Ducks need a house with good ventilation and plenty of space to move around. When you Build a Wood Duck House, it's important to make it spacious enough for the number of ducks you anticipate housing. Six to eight feet by four to five feet is a good, standard size for a duck house. Your duck house should have a solid floor (vinyl tile works well). They can lay on the ground, but having this solid flooring prevents predators from burrowing into their coop. Keep 1 to 2 inch gaps between the planks for ventilation, and make sure that the coop is at least 3 feet tall. Because ducks spend a lot of time in water and exhale a lot of moisture when they breathe, proper ventilation is essential to preventing frostbite in the winter and mold/mildew growth in the summer. The ducks can get infections if they are laying in urine or feces, so try to keep the coop floor clean. Covering the floor with some absorbent materials can help keep it dry and make it easier to clean. Try covering the coop floor with sand, straw, or pine shavings to give the ducks a soft, clean space to lay down. It's important to provide them a space where they can lay down and keep their abdomens dry.
Build a coop. Build the coop with wood planks. Keep the coop floor dry.