We routinely replace standard 30"-32"x60" bathtubs with Schlueter shower kits or composite shower bases of the exact same size, and I've never had a client complain that the shower felt too small.

A 36" wide shower is plenty big.

Hubby and I are both tall, our shower is 3x5, plenty wide. Our 6’7” son use it when visiting and wishes his was this size.

It seems that a 4 ft x 4 ft main area with a 3 ft wide area for door swing is plenty big for two people, if there are not elbows flying in all directions and you take turns under the shower head. My shower is 37 3/4 inches wide by 60 inches long. I have a big plastic portable shower seat that I can put on one end and when I stand under my centered rain head, which I later move under the spray so I can sit and wash. I have plenty of room to stand next to it as I wash my hair. It has the same floor area that a person would have, standing next to me. I am very big, too, I could easily have lost a foot on length in my shower and not missed it.

Forget the bench then this is a nice size for 2 . Get a folding teak seat use it when you need it and leave it out when not needed.

I’m not a pro and I love Patricia’s folding bench idea. When folded up, you will have permanent floor space that will feel luxurious. The whole bathroom design looks great.

Agree, ditch the built in bench unless you regularly sit to shower now. Also, get two shower heads. We've done a regular one and an adjustable handheld, plus a diverter, separated enough that both can be used at the same time. You can use one or the other or both. Handheld is great for cleaning or washing the dog, too.

Not about the shower, but the window directly across from the makeup counter is going to be a pain in the butt. The glare from the window will make it hard to see yourself in the mirror. If you keep it there, make sure you have really good lighting to overcome the glare. I know this from experience.

Our shower is 6'x3.5' and is plenty roomy with a teak bench. Two can fit, but it doesn't feel overly large for one. We have a wide shower head (rain head size, but wall mounted), and a separate hand held that can run at the same time. So I think you should be fine.

One comment on the water closet- having the door opening inwards is a potential safety hazard. If someone passes out in there, the door will block your ability to get to them out.

Is this a remodel or a new build?

It's a remodel. Staying within the confines of the existing bath and trying to keep things GENERALLY where they are so plumbing changes can be minimized, but we are making some moves.

These are such great considerations. I hadn't considered a folding bench. Honestly, I think the case of wanting the bench is just because you see it everywhere! It may not be a practical need. I also hadn't considered the glare from the window. In your experience, Barbara, did you have window treatments also? I think we are going to have a shutter on that window. Also very good thought on the safety hazard. I had not considered that. We'll need to figure out which way to have the door swing then.

I like having a bench- not strictly necessary but it makes shaving legs way easier and gives you a little more space for bottles and squeegees. It's also a place to sit when washing a dog. We decided to go with a freestanding teak bench rather than a built in one- partially to reduce costs and partially because of our particular shower door requirements that don't apply to your layout. A fold out bench might be a cool alternative.

We also just use a little shower stool for propping up a leg. Neither of us sits down in the shower. Easier to take out for cleaning. If we were ever in need of a stool due to impaired mobility, I'd think a more stable one that could be in the middle of the shower would be preferable to the bench. (I also worry about creating more places for the waterproofing to fail ...)

I would not like a built in bench in my shower which is 4 by 5 feet (with the shower head on the 5 foot wall). I have a corner triangular shelf for shaving, but I almost wish I did not have it as then you have to squeegee around it.

Definitely do as Crcollins advises if you want to have two people shower sometimes at the same time.

I would consider leaving out the makeup counter and putting a dressing table in the master bedroom. Then you can increase the size of the water closet - I'd rather there be more than 3' width there, just another foot. Is that a closet that opens to the other room? You would have to borrow room from there to widen the water closet tho, and use the space where the makeup counter is for a linen closet.

I think it's plenty big as well. But was wondering about your tub. If that is freestanding, there isn't enough room on the sides. Should be 12" space all around a freestanding tub.