I have plans of building a bathroom on the second floor next year. I am currently re-modelling the first floor and I would like to get the plumbing for the new bathroom in place so that I do not have to do any drywall work next year.
Can I rough in hot & cold water supply pex lines in the same stud cavity (marked with arrow in the picture) where there is a drain pipe running ? I've run out of space in the other studs.
Yes. There is no code preventing this. Also this makes sense because all of your leak issues are in the same place.
One other bit of advice - before you close up the wall get rid of the the metal and cast iron venting/drains. It will cost you $20 and the pvc will have less problems and last longer (and won't be flagged on future home inspection).
[Also electric should be stapled above outlet (yellow romex).
