The bath tub should be placed with the one end to the wall for the plumbing, and the other sides open, like a claw foot tub, with a shower, so it can be cleaned all around and underneath it. No silly looking caulking.
The sink can be placed on something you like.
And no shelves under the sink where you have to bend over and almost stand on your head to get something out of them. And bugs, roaches and spiders like the place.
The shelves should be eye level and a little below. And drawers under them.
The commode where ever it goes.
A window or 2 are needed for air, so there will not be a large amount of moisture build up that causes mold. A fan is needed to stir up air. You do not need a vent that bugs can crawl through.
