You’ll need to provide more info for us to help. Can we see the rest of the bathroom, and the floor plan? Are you planning on remodeling? Rent or own? Do you need storage?

No plans to remodel. This is a new built. There is a linen closet and some drawers with under sink cabinets. But I can use more storage space. Here are some pictures of the bathroom from both angles.

That is really strange. Where are your towel bars? Maybe a towel warmer???

Floating shelves might work.

It's a new build with a big framing mistake and the mistake was the size of the shower or the wall itself. Or a plumbing rough in error and a goof as to the toilet location, given it has a light?? . Who knows, but it is probably a case of "oh hell, just do this".

Have a carpenter give you good thick shelves wall to wall. Use baskets, it's nice storage. : )

Or create a make up nook for yourself.!! 32 wide, 80 h below/Ballard Designs

What is on the other side of the wall? Maybe that room could use an extra closet. Or you could split the space and have 20" deep shelves for both rooms.

The other side of the space is the toilet space.

" There is an empty bathroom area between toilet and shower."........: )

What is on the other side of the back wall? More interior space or is it an exterior wall?

I like the storage tower idea, plus towel rods (with maybe hooks on the skinny walls so you can reach from shower!). Would be tempted to put a comfy stool in case anybody needs to sit and put on socks, clip toenails, or otherwise be comfy in the bathroom.

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I'd put wall to wall shelves above a large humidity-loving plant on the floor.

Jilly….do you mind telling me where you found these storage cabs? (Esp # 4&5)

Coray, not at all! Give me a sec to find the links. Brb. :)

Coray, #4 is from Home Depot:

.

Sorry to say that #5 is no longer available:

https://www.harpgallery.com/shop/item43502.html

Lowe’s has this:

How about a make up vanity area? This is a photo from Emily Henderson's blog (Sara's Bedroom Reveal from May 1, 2017). I love the Fornasetti mural wallpaper and vintage vanity. This nook was off her bedroom, but it makes more sense in a bathroom.

Keep in mind.. not all furniture will do well in a damp environment..and if that is a closet at the end of the bath you may need a de-humidifier for that space

And personally I would not want to sit in that tight cubby facing the wall for any reason

redo the shower and extend it over into that space. I mean, what the heck?

I'd say do a built in linen cabinet, but you already have that.

you could put in some type of make up/hair vanity w/some type of lighting

float some shelves for towels,

(it actually would be a good spot for a water closet, but that means moving plumbing)

the space is otherwise very blah, doing this would give it some warmth and design.

your current shower is less than desireable, so if you have plans to remodel, just enlarge it.

otherwise, what do you want to do?

"No plans to remodel. This is a new built. There is a linen closet and some drawers with under sink cabinets. But I can use more storage space."

How hard can it be to get a handy man to kill the light at the circuit box ,reduce the depth to 24 inches via good old drywall add a door , shelve it and be done?: )

Now it's a bath with a his/hers linen closet set up.

Thank you, Jilly! (I’ve been looking on Chairish for something similar, but wider, 36”, for our downstairs LR; if I like something the piece is either too wide, too short, or way too expensive ☹️….the search continues!)

Is it big enough to install a sauna?

" No plans to remodel"............ that's what she said.

I would put some shelves in there and use it for towels and, I would put a pretty shower curtain over the entrance there. You could also put a hamper in that space.

Box it in as a closet. I don't care for any other option.

I’d not want another door in that bathroom.

You can mirror a single panel door. Or go back to the builder.

" I've no clue what to do here, but I need storage, and this debacle you left me, courtesy of some framing or plumbing error , makes zero sense. You know it, I know it. : ) It is supposed to light WHAT?

If interested in having additional storage, I’d remove the baseboards, create a fake wall just deep enough that a freestanding cabinet looks built in. Hopefully you can find the right size. You could paint walls white so it feels more built in.

Another idea is to still add a fake wall and add wide shelves stained to work with your cabinets.

It would be interesting to know what the plans for the house showed in that space.

At 39" deep it would be a challenge to fully utilize the depth on a regular basis. I guess you could just add shelves and put less-frequently-used items in boxes at the back. But that's why I wondered whether the back section could be accessed from the room behind, although I guess that might be considered a "remodel" by the OP.

Another option would be to put in pull-out drawers instead of flat stationary shelves. You can get heavy duty drawer glides that are long enough. Industrial strength so not cheap, but then you could utilize the full depth of the space.

If it were my house I'd hate the idea of losing storage space by adding a fake wall to create a non-functioning space. If you did put up a fake wall, maybe you could access the storage space from the toilet room, if it's not a good idea to access it from the room behind.

I would put a stacked washer and dryer there…but then again, unlike most modern homes, my laundry is on the lower level. It would be great to have one laundry off the master as we age….

Actually?

Unless you trully need he storage?

A washer / dryer stack is great.! WITH a door so you dont stare at it.

An upstairs laundry near the bedrooms is something that wouldn't work for me. I spend very little time in the upper (bedroom) level of my house unless I'm sleeping, so a laundry there would mean more running up and down the stairs. I also use my dryer very little and prefer to hang dry clothes, so my basement laundry is ideal for me. But if you would find it convenient, that's a good idea. You could vent the dryer through the attic, unless that room is on an outside wall. For those who have an upstairs laundry, do you put some kind of waterproofing or pan under, in case there is a leak? Or is that not necessary.

My upstairs laundry closet has a tiled floor with a drain. But I know someone else who has the pan underneath.

The real issue, is the OP has 15 good ideas. Has been gone from the building : )

I didn’t realize OP’s bathroom was second floor. I have first floor master with three bedrooms on second floor, guest room on finished walk out lower level.…laundry is in unfinished part of lower level…the part I should call a basement. That has always worked great for us but … everyone these days seems to want a glorious laundry room on first floor.and maybe in another ten years when we are late 70’s we would too.

It would be interesting to know what the plans for the house showed in that space.

Judging by the placement of the shower drain visible in the photo, I'm guessing a larger shower was the original intent.

The shower seems awfully small (assuming that is a center drain shower) for what looks to be a large bathroom.

Thanks everyone, these are great suggestions! Master bedroom and laundry are both on first floor.

I think the simplest and cheapest thing would be to put in a bench along one side and hooks for towels (up rather high) on the opposite side. Make the bench cushion something absorbent, like terrycloth, Use a waterproof cover under the terry to keep the cushion itself dry. (I got some flannel covered vinyl waterproof cloth at Joann’s recently) Have a place to sit when you are wet, but tired. Put a radiant light above this nook and you will have a place to dry off in the heat. Or look into a Valiryo Body Dryer for that space. You can install a Valiryo in a shower, but you don’t have to!

"Is it big enough to install a sauna?"

Not really. The minimum for a sauna is about 5'x6'x8.5'. Less than that results in not very enjoyable experience and the only place you'll see it is in the U.S.. In Europe people aim for about 8'x8'x8.5' minimum.

More: https://localmile.org/trumpkins-notes-on-building-a-sauna/