This looks like it has some good advice:
http://www.hipchickdigs.com/2011/12/the-new-duck-coop/
Note that the wire used is 2" x 4" welded wire, which is not predator proof if a duck is sleeping or nesting against it... read many horror stories about skunks and raccoons reaching through the wire and killing birds. Best solution to this would be to make the bottom 2-3' out of something solid or wire with smaller holes.
-Kathy
http://www.hipchickdigs.com/2011/12/the-new-duck-coop/
Note that the wire used is 2" x 4" welded wire, which is not predator proof if a duck is sleeping or nesting against it... read many horror stories about skunks and raccoons reaching through the wire and killing birds. Best solution to this would be to make the bottom 2-3' out of something solid or wire with smaller holes.
-Kathy