If you're building or having one built I'd have the door size match the opening+trim size so the top of the door aligns with the top of the finished trim. That will help with mounting the hardware to the existing framing of the pocket door and save labor and material

Terrible idea. Barn doors are for doors that do not need privacy and sound blocking. Which barn doors do not do any better than a pocket door. Much worse, in fact. You needs a solid wood traditional swing door on a PR. Unless you want to embarrass your guests even worse than they currently experience.

FYI barn doors are not sound proof so IMO a bad choice for powder rooms that often are off main living spaces and in your case the trim is so deep that it really would be bad I can’t tell from the pic if you might have enough space to build a pocket door instead

WHY? A truly very bad idea. The room is tiny and narrow, clearly why the pocket door is there to begin.. Second, one can tell from the trim, that a barn also doesn't suit your home if it was a "great idea" for anywhere. Leave very well enough alone. A noisy fan helps btw. : ) as will a solid pocket door versus hollow core.

And if you leave the trim, the door will provide openings, even less privacy. If you want a barn door, use it in a pantry, or even your master bath entry, but not for a "public" bath.

If you care to do it properly? it will require removing the pocket door assembly and the wall it slides into. It will require reframing , adding a full span header and re-drywalliing/trimming etc. Especially if its a solid core "real" wood door.

You can do anything you want in reality, but its not always so simple in many cases if done properly...- best

Tundra, I would have to disagree with the need to reframe the opening provided typical framing is existing. The existing header already carries the load above without fail as I see no cracks in the existing walls above the door. The added load of a solid wood door will not appreciably add to the existing load. Existing header is already in the 77" range to cover the opening and pocket. Typical SPF frame material will exceed L240 deflection, L175 would be the minimum for any door opening. Load bearing for typical framing should be in excess of 400 psi. Unless the install is for a soundproof vault door to muffle the roar of the jet engines within I would leave existing pocket in place, fill the voids and attach guides to existing frame material

Jan good thing you have eyes I did not even notice there was a pocket door so really why fix it badly with a barn door makes no sense at all

a big benefit of a barn door: you'll save on toilet paper as guests won't use the loo at your home any more.

Wow-I just learned a whole lot about barn doors from the comments to naomiyweung's question! From a non PRO (but who lives in an renovated barn), I was also (initially) intrigued by the barn door look when I started seeing them in magazines/on here/etc but think that they work best if they are large, actually serve a purpose, are in keeping with the style of the house and you get quality ones (not hollow, for example). Naomi, I would keep the pocket door. We have several that separate large rooms. When open, we have a very large space that allows the dining room, living room, den and kitchen to all "flow" (am not going to pretend I know much about renovating/decorating terms) and we usually always have them open. But they are very nice when someone wants to, say, watch TV in the den and not disturb or be disturbed by others. Naomi, you asked for a reason. What do you NOT like about the pocket door? You can always change any hardware or strip it if the wood is good and then stain it or paint it if it's a decor issue. But, as most said above, I really would NOT remove it. It's far more private as others have noted.

I have a "barn door" (though it's very far from looking rustic) that separates my main living area from my basement stairs. We did remove the door casings and did some drywall work to finish out the opening, and the door we used is solid, not hollow core. We did it because we couldn't install a pocket door due to electrical in the wall, plus it is a load bearing wall and we suspect it's a fire wall as well... we didn't want to mess with it, so a barn style sliding door it was. We also did it because the traditional door that swung was ALWAYS in the way and people in our family kept running into it. (And changing the direction of the swing wasn't an option because of the stairs leading down to the basement... the landing at the top wasn't large enough to accommodate a door swing safely.)
However, I would never use a door like that for a bathroom. You can see through the cracks on the side, and it offers very little sound dampening. (And yes, we made the door wider than the opening.) I love the door we made, it works great for the application we made it for (yes, we actually made our door) but privacy was not really what we had in mind with that door. ;)

Plus, with your measurements, you wouldn't have enough room to slide a barn door to the side far enough to actually clear the entire opening. Those doors need to be wider than the opening.

Thanks to all who offered kind advice!

Looks like I'm replacing my current pocket door since it is broken, hence the exploration of a barn door.

I second Sophie's suggestion of a traditional solid (not hollow!) wood hinged door; you may find it cheaper than fixing the pocket door.

Naomi, you have to check your opening. You have a 28" you will have to add additional 4" for door overlap for privacy so you will need a 32" door. Check your door specification guide to make sure you have enough room.

If your drawing is accurate you do nit have adequate slide space fir a door on either side. So no barn door. Not sure what is broken, but i am quite sure it can be fixed. Replacing unit would be involved but doable.

How would u lock it?

You wouldn't. That's the problem!

I would change it out to a hinged door.