All right, here is where I'm at now. I've abandoned the idea of taking room from my closet. I really like the space in there, and I think we've found a layout that will work within the existing room, while minimizing plumbing changes where possible. In the pic below, the vanity will stay here it currently resides, but we will add a second sink. The toilet remains NEAR it's current location, but actually gets enclosed... It is a short room, but meets code for 21" in front of the toilet. An enclosed toilet is a MUST HAVE. Currently, we have a large corner tub and small fiberglass shower. They are reversed in position from what you see on the plan below. In this plan we get a much larger tiled-in shower, with a glass door. I am hoping for two shower heads, and room for two people showering at the same time. The differences in the floor plans shown below are the size of the tub. You can see one uses a 5'6" tub, one a 5' tub. I lean towards the larger tub, but in doing so we lose width on the shower. The shower gets used daily, the tub a couple times a week for the kids, maybe once a month for a grown up. Thoughts?

Remove tub and put shower there. Remove vanities and put double sinks in an "L" where right wall is and where old shower is. Put a door to closet located on right, where the current vanity is, and close off other door. Move right wall of closet on the left to abut/share the wall with the closet on the right. Add a door to where the current left vanity is, to access your new exercise room. The benefits are that you wouldn't have to so a whole lot of plumbing modifications since the shower would now be where tub is, and vanity would now be where shower was (or at least close by).

Yes agree with Sophie that plumbing moves and how far will add $$$. But I would far rather have inexpensive porcelain tile, and a great layout ..........than luxury finishes w/ layout "settled for". Bear in mind, CONTRACTORS differ. What may be an arduous task to one, is not to another. A contractor armed with a very skilled plumber sub can often solve issues at less expense than anticipated. Maybe your contractor doesn't like the idea of STRADDLING a couple of joists on an opened floor, getting pitch and soil pipe relocated, without wrecking a ceiling below and using a couple 45 degree elbows. At least further investigate, would be my advice. I have moved them ( loos) further than that ! An additional 10k expense over ten years is a grand a year for great vs. "meh" or inconvenient.

You need to do a 2D floor plan with all measurements and to scale. Easiest way to do it is with graph paper