Bump...

the 'bump out' would be a nice spot for a make up vanity.

what is that with bi fold doors? remove it and extend the vanity. Do you really need an enclosed toilet? I'd turn the shower and put the toilet where the '4 x 7' is.

Thank you @Lyn Nielson. The bifold space is a closet for towels, supplies, etc. Vanity is 8 ft. as drawn. Would be 12 ft if we remove closet. Seems excessive no?

I'll play with your idea of flipping the toilet and shower. Toilet does not need to be completely private but I'd prefer that it not be a main visual feature of the room : )

Can you post the master bedroom as well with the hallway that has the old office door. I would like to see the hallway entrances to the bedroom and bathroom. Sometimes you are able to get more space by using the hallway itself by incorporating it into the bathroom. Also post the existing master bathroom because sometimes expanding it and keeping it in the same location allows you to use the existing plumbing to save on costs.

Unfortunately I doubt you will find the cost of moving plumbing will end your project. What does your current bath look like, dimensions etc. Lets think about function. Forget the WC and double sinks. Bathrooms are single use private spaces. Saves a ton of money and embarrassment . 4x7' shower is excessive. If this office is against the wall of the bathroom it makes more sense to steal a few feet rather than start brand new.

The space between the vanity and the wall looks to be a little tight. Otherwise, not a bad layout.

I think we need to see the original bathroom the size seems ample to me but I clean my bathrooms every day so bigger is not better IMO. Function first always . I hate toilet rooms they make no sense , no one should be using the toilet when someone else is in the bathroom ..Moving plumbing can often open a whole can of worms to add to the expense . Let us see the original along with the master bedroom plan . You never know maybe it will get us thinking.

Typically a dormer roof will have a kneewall. If your kneewall is not 8' high or you have a portion of sloped ceiling, then that might change the layout.

Thanks everyone for your generous thoughts. I'm posting the original layout from when we built this space 20 years ago. Hopefully you can expand to read it. If not, I'll try a pdf.

We've lived with the current bath for 20 years and it is tighter than what we want (always has been). I don't need much, but my wife gets frustrated by lack of counter space, nowhere to place her blow dryer and curling iron (when using) etc. 60 inch vanity is just too tight for double sink and space. We DO both use the sinks at the same time, so going to one sink is not appealing. I'll address other comments/questions below:

1. We worked with an architect 20 years ago when we did this addition and explore every option to buy extra space for existing bath. It is land-locked and very limited in layout/growth options.
2. We were planning on gutting that bath, but decided to explore re-purposing the office. We know it will be significantly more costly, but if it gets us a better outcome, might be worth it. (I'll only be working full time out of home office for a few more years, so can live with smaller workspace.)
3. Bump-out dormer: Roof is steep gambrel, so "knee walls" are all 8+ ft tall. No height limitations.
4. Toilet "room" is not essential, but there are plenty of times when one of us is in the shower or at vanity and the other needs a quick pit stop. Some privacy for the WC would be nice.
5. One alternate option I've considered is adding a door at end of hall just to the left of the laundry (on the print) to create a new entrance to master suite that includes office, bath & MBR. This would create some flexibility I think, but may turn into more of a major remodel than desired.
6. Note everything to the left of the Washer/Dryer and "Existing Bedroom" is a 2nd floor addition built 20 years ago. The first floor below the addition is either garage (far left) or a small room on slab. The ONLY way to get to plumbing and waste lines in basement is through the original house (current master bath connects to drain in laundry wall). In other words, the new plumbing can't stray too far left!

THANK YOU!

I did some crude editing of the existing floorplan to illustrate the alternate option I described in point #5 of my previous post. See attachement.

This leaves the existing bathroom and plumbing as is, but extends the vanity by around 3 ft, which may solve our main issues.

It leaves some extra space at end of hallway (cross-hatch area), which could become an extra linen closet. I don't love that the new bathroom door would block the window when open, but probably not a show stopper.

Thanks 3onthetree. The design I shared is a 2nd floor addition we did over the garage. Long story short: we couldn't find a way to locate bathroom in a more integrated way while still accessing main house plumbing. As you point out, it is sub-optimal, hence our reason for revisiting, even thought we are still somewhat handcuffed.

I think your idea could work, but the hallway seems tight to get furniture in and out.

This idea gives you a larger vestibule into the bedroom and you can keep the window unobstructed.

If you want to go whole hog, this might work. I have a built-in dresser in my hallway to the bathroom that i really like. 12 drawers on the bottom about42 inches high, two less deep cabinets sit on top with a mirror between them.

Thank you Karenseb! I like the angled wall option. I think that solves for a couple issues and leaves less awkward space. Not ready for the whole hog approach, though it is a better overall suite layout. Unfortunately, I do still need an office somewhere in here... Much appreciated.

If you were to re-evaluate more of the original addition, this was my initial read on the plan. It's half-baked, but introduced an ensuite layout rather than split bath/closet, and worked around respecting the dormer sloped ceilings:

Thanks again @3onthetree. If I could go back 20 years, this layout would have been worth considering... but more than we want to tackle today!