Moving bathroom plumbing question

Are the supply and drain lines plastic, copper, or cast iron?  Plastic and copper are easy.  Cast iron supply lines will require a threading machine so that is something you would have to have a professional do.  He will probably just make a transition to plastic or copper and then run the new material into the wall.  The hardest problem you will have is the drain line because it is a bigger pipe larger and you have to have a vent line.  If you are tearing up the wall and floor anyway, this is not a big job.  I would expect to pay a plumber $200 to 300 for moving the lines if the wall is already opened up and nothing is wrong with the original piping that has to be corrected.

TW

It is not a big deal to move water lines. 

(all of the below assumes your house is not built on a slab.  If it's on a slab, moving the lines is possible, but a bigger deal, because you have to cut concrete)

There are a couple of reasons that the water lines might come through the floor:

1.  Is this an "outside" wall?  Plumbers are always loathe to run plumbing through outside walls, especially in northern locations, for fear of freezing.

2.  The bathroom might have already been remodeled once, and the sink moved to its current location.  It's always easier to fish new lines through the floor than through the wall.

Since the new remodel includes a new wall anyway, it will be very easy to put the water lines wherever you want them. 

Thank you both.  It turns out that the water line situation my husband was thinking of was in the kitchen, not the bathroom. The bathroom is a standard set-up. (The kitchen is on an outside wall).  Crisis (not really) averted!  I appreciate the info, though, it will surely come in handy in the future.

Yes everyone likes to have a window above the sink (for some reason) so it is very common for those pipes to come up through the floor.  (it also means you can open the door under the sink to keep the pipes from freezing. 

Good luck with your remodel!