I'd go for 2 sinks. You can get a couple of 13-14" sinks and place them toward the sides, which will give them some counterspace between the sinks. Don't use a thick sidesplash and that'll save you a few inches. Make sure the vanity has plenty of storage, whether built in or made with various portable bins and shelves.

In a very short while they will not wanting to share the bathroom for their daily ablutions.

One sink will be better, and then they will have more space to spread out what they will be using, their shaving implements or their makeup.

The other advantage of having only one sink is that you can make the sink nice and large so they don't get water all over the counter when they wash their face, and most importantly, there will be less plumbing underneath, so you will have a lot more room for lots of drawers.

What they will really need is plenty of countertop for each kid, separated so"his stuff is in my waaaaay" isn't the refrain. And a bank of drawers each. And a medicine cabinet each. Then decide if there's room for two sinks. They will never be in there at the same time, so the only reason for two sinks is that no one wants to use the sink when the previous person left toothpasty suds on the handles or didn't wipe out after shaving. Great time For them to learn that housekeeping.

Two kids one space with water??? Never. Taking turns is not an over the top expectation and it sure would help their teachers out!!!

Not enough space. ONE sink. Nothing less than 72 inches is remotely practical and don't give me the "I see them online everywhere" thing. Or show us the bathroom in a drawing with every dimension.; maybe you have other possibilities. Your kids are not even same gender. Put a vanity / make up table in the teen girl bedroom for the junk that would be in the bath. .........and ONE sink in the bath : )

PS.......... Try to remember that before suburbia morphed to No sharing" it was totally common for all in the family- two adults, three kids to share ONE upper hall bath . Nobody DIED. I am very much alive despite having done just that. Never late to school, either.

I shared with my brother when I was a tween and he was a teen, until he left for military. I don’t remember ever being in the bathroom at the same time. There was 1 sink. My mom gave me a small vanity table with a mirror in my room. I think 55” is too small for 2 sinks. Drawer storage and medicine cabinets are more important IMO. Put separate hooks or bars for towels, and an extra hook or two behind the door. Robes can stay in their personal closets.

Put a container of wipes, or a spray bottle of Mrs. Meyers and a microfiber cloth under the sink and tell each kid to wipe out the sink after each use. Once a week they can throw the cloth in the laundry. Make sure they don’t flush the wipes if that’s what you use.

My mom was strict about one aspect of sharing: definitely lock the door when using the toilet but never when showering.

If the kids use electric toothbrushes, it’s a nice upgrade to have electrical inside the medicine cabinets for charging them.

One sink there is no way a preteen girl will use the bathroom at the same time as her brother . In fact this set up is asking for a very bad situation as they age. BTW 55” is not big enough for 2 sinks . I would get my daughter a nice make up table for her bedroom so that she can do what is needed in the bathroom and then do her make up in her room. MY sister and I had a fight every morning until my Dad made 2 bathrooms .

Unless you have space for two completely separate vanities, don't bother. You would be better served with one sink shared and larger side sections of countertop for each person's materials and mess. When I was that age, we had a bathroom with two separate spaces. My brother had the sink behind the door that he could avoid cleaning until the dirt threatened the entire room. I had the main more convenient sink just inside the doorway that was used by everyone except my brother. He had his mess and I had mine but my items were on a vanity inside my bedroom.

I say one sink as well.

Is there also a powder room on the main floor? That can be used as well to brush teeth etc. if the person can’t wait and is in a rush to get out the door.

Wow! Thank you all. There are some strong opinions on this and I agree that it seems one is the way to go. They will never be in there together. there are 2 additional bathrooms on the upstairs they could use in an emergency (master and other daughter’s en-suite) as well as the full bath on the main floor and another full bath in the basement. I thought they’d prefer to have their own sinks but I think counter space is better.

Here are the upstairs bathrooms (bathroom in question is bath #2 in the middle). Do you think the layout is okay? Should I swap the vanity and the toilet? Not sure if it’s too late for that change...

and also want to add... we basically all share a single pedestal sink for our family of 5 right now so this will for sure be an upgrade!

Concur with others. One sink, lots of storage, more countertop space

My daughter has a toilet next to the vanity like you have shown in the middle bathroom layout.. She can not access the area next to the toilet. I would move the toilet closer to the tub and use a vanity with the sink on the left portion with drawers on right side of the vanity, How wide is that bathroom? Even that idea may not work.

Thanks all. I reached out to my architect Re:placement of the toilet.

Architect updated bathroom plan to move over toilet closer to tub. Much better!

Thank you Jan. The toilet cannot be moved to that wall becaise of where the current plumbing lines are.

We do have a linen closet for towels, plus there will be towels under the sink.

I’m not troubled by the toilet door scenario that much. To be honest in 2.5 years my oldest goes to college so it’s likely that the youngest will take her room and this will basically be my son‘s bathroom until he leaves for college.