Lady Penelope your change entailed changing a plumbed area to another plumbed area.
In this case, if the kitchen is being moved, then you would assume that plumbing (including most likely gas) and electrics will have to be installed. From what NL has said, there is no swapping of wet areas here.
I think you may have missed my point, if you relocate a kitchen or bathroom, those rooms are exempt from the usual rules applying to floor coverings and sound insulation. If you are the hapless person underneath a relocated kitchen (or bathroom) you are going to be subjected to much greater sound levels, and there is nothing you can do about it.