Wow, so many nests for such a tiny coop! If ducks are anything like chickens they only need 1 nest for every 4 or so birds. You certainly wouldn't get 24 chickens in that coop let alone ducks! I'd consider removing the dividers on one side to give them more room. More room us always better, right?
I don't see any ventilation. I see windows. Great for hot summer allowing cross breezes to cool off the inside, but windows are not ventilation. They become drafts in winter unless tightly closed. Ventilation needs to be well above the heads of the birds when they are standing up tall at their highest point inside, which for chickens would be when they are in their roost. Ducks I believe stay on the floor. That makes me think that the metal floor is going to be cold in winter. I'd replace it or at least cover it with plywood.
As for the pole at the roofline..

Chicken roosts need to be higher than the nests so they don't sleep in the nests subsequently pooping in them and on the eggs. The builders got that part right. Their roost should also be far enough below ventilation that a full grown chicken can fully stand up straight on the roost without reaching the ventilation with their heads and be free of drafts from any angle. Those windows, even closed, will have drafts blowing right up their skirts. So, no, just no. That "roost" is senseless. And again, where is the ventilation?
I think you can adapt this coop for your ducks. Cut off the underside part so the coop is closer to the ground, set on bricks or something to prevent the wood rotting. Put plywood on the metal floor. Remove partitions from nests on one side. Make lots of vents up high around the roofline and those triangle points.
I'm sure duck people will have even better advice. Best of luck to you and your duckies!

Good on you for saving these sweeties
