pics?

A scaled drawing of the space, with all dimensions, of walls, window, door etc

Then add pictures, j pegs for all of that.. Everything about anything ......in any bath, is about inches. Clearances.... function first.

Hi. Design is both an art and a science. For the art part, we need photos of all 4 walls. For the science part (mostly math) we need a to-scale floor plan. Also, coming into play are required clearances in a bathroom. Example, there are specific clearances for both the sides and fronts of a toilet.

I cannot give you advice without that information.

Also, I am unclear if you want to add a linen closet or expand the footprint of the shower or both.

Thanks!

If I am picturing your space correctly I would probably try to find something about the size of this cabinet for next to the tub. (light blue space) (Gray is the door that was removed)

https://www.wayfair.com/storage-organization/pdp/dotted-line-nina-2363-w-x-2756-h-x-1181-d-free-standing-bathroom-cabinet-w004801681.html

I would also add some shelving on the wall over the toilet and this piece for additional storage.

You could do a taller piece next to the toilet, but make sure you don't make it difficult to reach around to turn on the water. (Again, guessing this is the side where you turn the water on and off - usually plumbing is all on the same wall).

I would go with shorter so I could pull it away from the wall more easily and clean around/under it.

A pretty hamper could also go in that space with shelves on the wall.

Depending on the style of your bath I might do a DIY pipe shelving unit that goes from the vanity to 6" from the tub and simply doesn't have shelving where the toilet is. but feels like one cohesive unit.

The pipe shelving may technically be a code violation because it interferes with the 15" space between the toilet and vanity and the pipes are connected tot the all, but I wouldn't care. It isn't like the code inspectors will come knocking at your door.

Thanks