HORRIBLE! So sorry , that is a big NO.

Pick tub or shower, and not both.

Put feet and INCHES on your plan for us lazy USA TYPES. that means walls, windows, entry all.

No to a "stud wall" too.

Far too small a bath to support four bedrooms... but provide more info.

Agreed with kandrewspa—I would do a shower/tub combo where the current shower is, possibly bumping into the hallway a bit, put toilet between tub and window wall, and preserve the length of the other wall for a double vanity. Kinda like quick sketch attached

And whatever you do, you don’t need to add a wall inside of the bathroom and block the natural light— it’s pretty easy to have an L-shaped metal bar fabricated to hold a shower curtain around your shower area.

Why can't you do a tub/shower instead of two separate footprints? Here's what we did for a recent client.

Beauty and the Baths: Guest Bath · More Info

Here's another for a different client:

Burlwood Drive Bath · More Info

Keep the windows inside the tub/shower, but either raise them to clerestory height or get frosted glass:

Tamara Mack Design - Interiors · More Info

Volunteer Park Residence 10 · More Info

Jumping on the bandwagon here:

- You just don't have space for a tub + a walk-in shower. Your obvious answer is a shower-over-tub. DO NOT try to cram in too much. Your proposed floor plan will never, never be comfortable.

- Absolutely no to a dividing wall anywhere in this space. They're not a great idea, even in a larger space.

- Consider storage. You won't be able to have a linen closet ... but maybe you can squeeze in a 16-20" floor-to-ceiling linen tower. I've had such a thing in a bathroom, and it absorbs SO MUCH STUFF. Towels, cleaning products, etc. I also like the yellow and white bathroom above, with its drawers above the toilet.

- Still thinking of storage ... could you place a shallow storage unit at the top of the stairs? A short cabinet with a lamp on top could hold towels. A closed wardrobe could hold towels and extra toiletries. But it has to be shallow, or you'll cut in to your walking space.

- Forget tubs with larger footprints. A builder-basic tub is usually 30-32" wide x 60" long. Unless you're big or tall, this is enough ... but consider getting a DEEPER tub, which is nicer for soaking. Again, deeper ... not wider or longer.

- Try hard to work in a larger sink vanity. Consider a toothbrush holder, soap dish, and grooming items. You will not enjoy balancing things on the edge of the sink ... you need some counter space.

- Four bedrooms'll share this small bathroom. So be sure to include space in each bedroom for doing hair, make-up, etc. I grew up with 5 siblings sharing a bathroom (2 girls, 3 boys), and it was never a problem ... but we dried /fixed our hair, etc. in the bedrooms.

- I like the sketch PD Schlitz drew ... except that I wouldn't try to squeeze a duplicate sink into this small space, and be sure you don't put a mirror dead-ahead of the toilet. Not the most pleasant view while you're sitting.

- Starting from your own concept, I'd keep the shower ... move the toilet to where the tub is now ... give the lower wall to a wide vanity + linen tower.

- Consider that toilets must have 30" of width.

- A wall-mounted toilet could save you a few inches. Its only negative is that it's harder to install, but you're probably having a pro do this work for you.

- Perhaps your door could hinge OUT instead of INTO the room; that is, save the door swing space.

- Go with a light-colored tile and use the same tile on the bathroom floor and behind the tub. Visually this'll make your space look larger.

- I personally prefer a shower curtain, but -- in a space this small -- this is a space for a frameless glass door, which will make the space feel larger.

- Try to make the mirror over your vanity as large as possible -- again, this about making the room feel larger. Just don't provide a view of yourself on the toilet in this mirror.

- Do not fail to consider where you'll hang your towels ... make sure they're easy to reach from the tub/shower. You do not have space for this towel warmer.

- Consider where you'll place your trash can. Small things like that can turn into small irritations every single day.

Without a doubt, no wall.
You can install a 3/8" clear tempered glass divider after extending the shower to the bathtub. To save money, the plumbing system does not need to be redone.

Sabrina, how did you waterproof those drop-in (undermount) tubs? And how did you provide the proper slope on the ledges to drain into the tub?

@Catbuilder

You buy this

and you get this......when you read all the specs and have a competent contractor, and pro tile guy: ) ( ala Sabrina above )

If you're showering? The liner is INSIDE the tub. The glass shower door is no different than on a curb at a shower entrance.....you aren't going to have a flood : )

Than you all for the advices, you have helped us make a change in the design and avoid stud walls inside the bathroom.