We have four muscovy ducks, one drake and three hens.
They have a purpose-built coop with the sides some 6 by 9 ft, and an inner height of 6 ft, so people can stand inside without trouble. The pop door is large in order for a tall drake to walk in and out easily, 20 inches tall and a foot wide. In order to keep drafts out, a large box is hung outside the pop door, with the opening to the side, so the ducks have to make a 90° turn to enter or exit. The opening has a closable hatch. A small plank with smaller wooden steps added to it acts as a gangplank connecting the opening with the ground.
There is one large nest there, two feet by 16 inches. The opening of the nest is deliberately kept small, some eight by eight inches, to discourage the drake from entering and disturbing the hens and ducklings. The nest sits on the outside of the coop, and its roof opens up with hinges, making egg collection and cleaning very easy.
There is also a large natural log, perhaps six inches thick, put up as a roost. It's about two feet from the floor and six feet wide, stretching from one wall to the next.
The walls and the nest are insulated.
There is one ventilation opening high up on each of the shorter walls, each opening a circle of about six inches in diameter, covered by hardware cloth to keep predators out.
The walls and ceiling are painted white, and the floor is covered in tiles. The tiles in turn are covered in wood shavings. Wood shavings are also used to cover the bottom of the
nest.
One of the long walls has one large triple-glass window, stretching from roof to ceiling.
The hens only use the coop three times a year, when they lay and sit on eggs in the nest. When the ducklings are one day old, they leave the coop never to turn back. The drake never ever uses the coop. They all prefer to sleep outside, even in sub-zero temperatures. Sigh.