We made ours out of plywood. It is an open square (four sides but no back or front) with partitions in it making four even sized boxes. It sits up against a wall for a back and has some old trim nailed on to keep the eggs from rolling out. In restrospect, I would use something that could be cleaned out more thouroughly, such as the crates, but my hens lay in these boxes every time so I guess they like them!