I had to replace the entire rusty, dripping, cast iron drain in my house with pvc and demolish my second floor bathroom. My first floor bathroom is stack-vented so how can I properly update and relocate the second floor bathroom? I do not want to reuse the old bathroom location, it was too small (5x6.5) and make it a closet. The toilet, sink, and tub will be about 15' from the main stack this time. Drawings are GREATLY APPRECIATED! Thanks for the help in advance!
-Tony

You could position the new bathroom over a downstairs wall that can take 3" width, and add a new stack, roof to basement. If an old house and a 2 x 3 wall (3" = 2 3/4"), you could remove 1 width of plaster and lathe (often 3/4-7/8"), add a strip of wood to the studs, and put in 3/8" drywall. I'm assuming such a house from your picture.
Put a new vent out the roof, and run the waste line 15' along the basement.
The other option is removing 15' of floor upstairs, and would have to run in the direction of the joists and so on, seems too much to me.

The other option of removing 15' of floor upstairs was a great idea, and is almost complete (yes I have some time off). Therefore, can you please draw a code worthy dwv system for this 5x8 bath for me? I have no issues with labor or drilling holes for a vent through the roof. The bath rough-in plumbing will be about 15' from the main stack and pipes will be parallel with the floor joists. As always, thanks for the help joypulv.
-Tony

I don't have a code book for a worthy drawing (others here do) plus there's attic ceiling height and joist size and span, and the pitch of the roof for the vent height above. Invite the inspector over; that's his/her job. If you have 8" joists, you have just enough room for the slope on 3" pipe. Draw the entire attic showing joists to pitch of roof as well as the whole house elevation and that should make him/her happy.