My friend is buying a house that has only a bathtub, no shower. She needs to add the shower head and faucets. The current design has the separate hot and cold taps with one spout. She mentioned that to buy the new faucet that adds the mixer and the shower and had the plunger in the spout is really expensive. She doesn't want to tear up or replace the tile. I suggested that since she has access to the plumbing that she tap into the H&C pipes and run a separate mixer faucet to the shower head. Leave the tub faucets to run the tub and the shower for the shower. No plunger needed.

She got really upset with me and said that was the dumbest idea ever. She could barely grasp the idea. She was UPSET. Which made me laugh, but beside the point.

So, I thought for a second and wondered if this was strictly a U.S. thing. I grew up in Australia, have traveled to different parts of the world and I believe, only in the North America, do you have to use one faucet and a valve to go from tub to shower. Is this the case? How many in the U.S. have separate controls?