As I prepare to close up some walls with drywall on my first floor, I am looking at old galvanized piping which runs up to one of the two bathrooms on the second floor. The newer master bathroom has new 3/4 copper piping in an area that I can access at any time and would be able to tap into these lines for the older bathroom remodel in the future. These 3/4 copper lines run approximately 24 feet from the water heater and cold water supply to where I would tap into them. Both bathrooms are actually situated back to back so the piping would be easier to install utilizing the existing 3/4 copper to the master bathroom as opposed to running new copper piping from the basement. This configuration would supply in total 3 sinks, 2 toilets and 2 tub/shower areas. I would continue to use 3/4 copper to the rough in walls and then go to 1/2 inch to the fixtures if this would be appropriate. So my question is....Will the existing 3/4 copper be sufficient to supply water to both bathrooms in an efficient manner with out running a new circuit to the older bathroom? Help me out Plumbers as the drywall man will be here soon! Thanks Russ