Show a floorplan and more photos, to see where storage could be added.

Is that towel bar for the bathtowel? Is it easily reachable from the shower without dripping on the floor as you reach? Or, if it is for the mat to dry after a shower, where is the towel?

The shower didn't need glass on that wall. If you had closed it in, you could have done a nice built-in with drawers on the bottom and doors on the top.

You had plenty of room for storage.

Using recessed medicine cabinets over the sinks would also have given you storage for items you use everyday.

Sure you can add a freestanding cabinet, but the back won't be finished/pretty and you would see it from inside the shower.

If you had skipped the glass on the that wall, you could have had something like this. This is mine and it is just outside the bathroom in my master bedroom. I keep spare towels, sheets and toiletries in there.

That's an idea. Hmmmm. What about a low cabinet that would match the vanity across from it?

The open window in the shower is nice even though I would feel very exposed. It looks like there was enough room there for a closet to be built in that area if the window/opening weren't there. Would a short low cabinet against the wall give enough storage?

Probably

Just need something for meds/ heating pads/ sundries. I can always keep towels in my walk in closet.

Be, I love the idea of the cabinet in the picture, but removing the glass -we'd have to complete and tile the wall on the inside of the shower.

This is the layout.The space under the window from end to corner is about 4.5 feet. The height fe floor to window is 42

Current Layout

I would definitely put a cabinet, or even open shelves, in the space next to the shower, below the opening. You can use baskets to hold your sundries.

We remodeled our primary bath in a previous house and took out a large cabinet that was used for towels etc that was by the vanity and replaced it with this dresser my husband built. I imagine a narrow dresser would fit nicely there

A pic:

Another vote for a narrow cabinet against that wall. @clergychick’s idea is pretty and practical.

Love that!

Good idea!