I need to re-plumb my condo because of polybutylene piping. I live in a building with only one unit below me and my neighbor and I have decided to do the re-plumb at the same time. The plumber that we have been talking with wants to run both our pipes through the down stairs unit and drop her pipes down and have mine going up into my unit rather than re-pipe mine through the ceiling as they are now. Are there any potential problems with this re-plumb (I'm re-plumbing in copper). It worries me that my pipes would be in her ceiling and I'd have to go into her unit if a problem occurred, but maybe I'm over thinking this