Appliances such as tubs, etc. are used less frequently and use much more hot water at a time, so the initial wait and the waste of the hotwater left in the pipe should not matter so much and a high flow rate is more important.
Running separate pipes of different sizes to the same bathroom is no problem if it will improve performance & save energy. I realize that running the lavatory faucet and a tub/shower would require filling two pipes, but this will seldom be done at the same time so the water in the pipe would cool down between the uses.
Question: What size pipe should I run to each type of appliance?
Lavatory: Sink: Tub/Shower: Whirlpool: 3/4" as valve inlets are 3/4" Dishwasher: Washing Machine:
Thanks so much for your help.