You are going to want more than 32" for the toilet. 36" is standard (and perhaps even code in some areas???? Not here in Maine but I heard people saying that on other forums...) We have 34" and it feels fine but I dont think I'd want to go much tighter. You could solve that simply by flipping the closet and shower. So, have your shower -rotated 90 degrees and witha glass end wall- at the end of the tub (which is a nice setup you can see in many bathrooms, the tub deck can actually protrude under the shower glass wall and be a ledge or seat in the shower). Then the passageway moves to the left, and you can steal a bit of space from the other closet for the toilet. Either that of have a shorter vanity. 48" isn't a size I'd fight for. It's too short for a double vanity, really (unless you're using one of the new two-faucet 'trough" styles) so why not go down to 42" and have a better toilet area? For resale, though, you should consider a double vanity. Some people I guess expert truly huge ones, like at least 5+' long. But you CAN get smaller ones, Ikea has some great ones for tight spaces. But if you're not selling anytime soon, do what YOU like!! (But I still think you'll want more toilet space...)

Exactly what kirkhall said: ask the contractor what is POSSIBLE not what you should do, then make the decision for yourself. If you really want just a single bathroom, certainly that's your decision. But as others have said, it sounds like there's room for two. As for resale, you could check with a local realestate agent. However, in general, homes with two bathrooms would be worth more and probably sell faster than homes with a single bathroom. Growing up, we shared a single full bathroom (and my parents had a half bath of their own). In the full bathroom, the shower and toilet were separated from the vanity by a pocket door. For us that was quite functional. If you do opt for a single bathroom, consider possibilities of separating functions into rooms with pocket doors or something similar to allow privacy. If you post a layout here, I'm sure people would be happy to offer suggestions and options for you.

benjesbride I absolutely LOVE this idea! Is moving a waste line more of an issue than moving the plumbing lines? I've always hated that the toilet is right at the door and would like to add a partition wall between the would be new vanity and toilet location. There is a vent in the rear of the existing shower (from bottom to top of building) that is about 12" wide. It's goes all the way to the end of the foyer closet. That leaves us with about 72" of space along the foyer closet wall to add a toilet and vanity. I think the toilet requires 30" so a 42" double vanity (or two smaller single vanities). We cannot have washer/dryers in this complex (old 1950's plumbing). But I've always complained about no linen closet in the bathroom so that works too. I'd like to move the door to the foyer; however, that would require a split vanity due to the heating pipes in the middle of the room along the wall behind the existing door. No, we are not adding a bedroom. That may be a later addition though, years from now. An neighbor converted the rear of the living/dining area to an office/bedroom (photo below). I've tried to adjust the floor plan to add the vent/shaft in the rear of the shower. It may not be worth the time and expense to open up the foyer wall if we can't get a great layout.

I agree with Cpartist"s layout and like moving the closet over as suggested by D M so that bedroom 3 has easier access to the bathroom. Do you have room to have the toilet face the tub and add a linen cabinet next to the toilet? How wide is the tub toilet area?