The time has come to talk roughing in with the plumber. He will be working on a shower stall which has a showerhead and handshower, both controlled by a thermostatic system, and a tub/shower combo also thermostatic (no handshower). Are there guidelines about how high the showerhead goes (tall husband), where to place the handshower, where the volume controls should go (like, the one for the tub spout should be x inches above the tub), etc? Any help would be much appreciated!