I'm about to start a bathroom "facelift" which means a complete retile, new vanity and vanity top. My contractor built his entire house, doing all the plumbing and electrical work. My question is this:

If the new vanity is taller and wider, then the sinks have to move 3 inches to one side and up. Does this require new plumbing, or is it a simple redirect? I'm wondering what the risks are, and whether this would be considered "replumbing" if he doesn't have insurance.

ps. I know him, so I trust him, but I'm concerned about the liability in my building. No matter how skilled, shit happens.