I've never seen a 'duck house' -what does a duck house look like? A large dog house?
Basically yes. It is elevated off the ground an inch or so for ventilation/airing and bedded with straw inside and straw baled outside so they can rearrange as they wish. “Wild” ducks will lay anywhere that offers some protection and tend to make use of them. We had a “duck” house growing up that was used by our domesticated Pekins/Muscovies but later was used by wild Mallards as well. Duck eggs are duck eggs. It was next to a stream, so they could quickly escape to the water in case of predators, and we would occasionally dump cracked corn or feed nearby to sweeten the deal.