I have a very good grasp on the features needed in a house to keep ducks safe from predators. What has worked for you to keep the costs of these structures low while keeping duck safety factors high enough?
Work like you were living in the early days of a better nation. --Oysterband
I used pallet wood to build our duck house, our two pig houses and even part of the donkey stall house.
all of these are roofed with reclaimed aluminum metal roof material (the donkey house is fully covered with it)