My ducks are free range in the fenced yard other than during baby fox learning to hunt season. Then they are penned up.
Their pen has the chicken house (raised up for ease for us) and the duck house, same concept, but just off the ground so it doesn't flood and the ducks can still get in.
The girls like corners of their house. They lay their eggs in the nest box 98% of the time. They lay in the wee hours of the morning, so have laid by the time they are let out.
They are locked up for their safety every night. Nothing is getting into their house (other than a snake - which has been in there before). Their pen - it is open, so while wired to keep land critters out, flying ones could still get in.
When they are in their pen, they have a kiddie pool. When they are in the yard, they have their 11x7 pond that they hang out in.
The pool in their pen gets emptied 2x a week. Their pond, 1-2x a year.