Unless you install a unit at each bathroom, there is no economies to their operation. They are more expensive to purchase, parts are more expensive, if you can find them (which is not always the case), and electric models require large power lines. A gas unit still requires a gas line and flue. The only advantage to a tankless model is that it takes up a little less room, but it is not that much smaller. in the total space required for servicing, etc. : Im about to start building a house and would like to hear from people who have tried tankless waterheating. : Make model and any experiences (Good ot Bad) would help me make my research