We have a friend who recently replaced their old electric water heater with a natural gas unit. Due to local building codes, they couldn't use the spare flue in their chimney. It had to be moved to an outside wall of the basement, and had to have an electric fan in the exhaust duct work. These code restrictions forced them to locate the new heater at the far end of the basement, which increased the distance between it and the kitchen. He's on city water, and was not happy with having to waste a few gallons of water every time he wanted hot water in the kitchen. He eventually installed a circulating pump that only comes on when he manually pushes a button switch near the sink. It recirculates the unheated water in the hot water pipe back to the tank, so he has hot water instantly when he opens the hot water faucet. He loves it, it only runs when he manually starts it, it only runs for a few seconds, and he claims it saves him money.
Since this will be a new build, a few suggestions from a NON-plumber... When we remodeled our kitchen, I did all the kitchen sink plumbing myself. The old drain pipe was hard-cemented black PVC (I'm not a plumber, so I don't know the exact name of the stuff) into the wall. I had opened the wall behind the kitchen sink cabinet, so I could replace that drain pipe connection. Where it exited the wall, I terminated it with one half of a PVC UNION. This way, after the wall was closed back up, and the new cabinets were installed, the end of the union just entered the cabinet, under the sink. I attached the mating part of the union from inside the new cabinet, and continued to plumb everything to the new sink and garbage disposal. Now, if a trap or the disposal, or anything else under the sink ever has to be replaced, the entire drain system can be removed, reconfigured, or replaced by simply breaking open that union, and doing whatever. Nothing will ever have to be changed behind the cabinet or inside the wall. The guy who installed our new cabinets said he's been installing cabinets for over 20 years, and NEVER saw anything like that. He thought it was "genius."
When we remodeled our living room many years ago, we removed a conventional door and installed a "pocket" door. We have a two story house, and the water pipes that supply water to the upstairs bathrooms were exactly where the pocket door would open, so I had to move them. When I relocated them, I made a PVC "inverted Y" in the feed to upstairs. The bottom of the "Y" fed the upstairs lines. One side of the "Y" was connected to the supply line (through a ball valve) and the other side of the "Y" was connected through another ball valve, to a male hose connector. I did this for both hot and cold water feeds. In normal operation, the ball valves connected to the hose connectors are CLOSED, and the feed valves are OPEN. In this configuration, the upstairs is connected to the hot and cold water supplies as normal. A few times so far, I've had plumbing problems upstairs. Before doing anything, I go downstairs in the basement, and CLOSE the feed valves, and connect a garden hose, or just hold a bucket under the hose connector, and OPEN that ball valve. This DRAINS the feed lines going upstairs. It helps to have my wife open the furthest faucet upstairs, which allows air back into the pipe as it drains. With both hot and cold feed pipes drained, when I open whatever the problem is upstairs, I don't have water all over the place. The main reason for this setup, was so I can cut off the water upstairs, and we still have, and can use water in the kitchen and downstairs bathroom. I don't have to shut off water in the entire house to work on the upstairs plumbing.
As I said, if you are building new, these are just a few simple ideas you might consider that may make your life a little easier down the road. Take them for what they're worth, as I said, I'm NOT a plumber...
