This type of plumbing is also referred to as a “stacked riser” plumbing method where a pair of pipes delivers cold and hot water to similar unit configurations that are stacked on each other in a multilevel building. A separate pair of hot and cold riser pipes will generally supply the kitchens in a stacked configuration and another separate pair of riser pipes will feed stacked bathrooms. The pipes typically branch behind the interior walls creating multiple points of entry for hot and cold water to an area.

In this scenario, water usage is most economically metered at the point of use. For example, a single bathroom apartment with a dishwasher would have eight points of use that are metered: three points in the kitchen (one hot feed for the dishwasher and vanity and one cold feed for the vanity) and five points in the bathroom (toilet, hot and cold feeds in the vanity , the tub and shower). The smaller sized flow meters deployed at each point of use are generally rated for up to eight gallons per minute and are attached to electronics that convert the flow meter signals into gallons of consumption. The meter electronics interface to a wireless transmitter to allow the meter to be automatically read. In many states, the owner has the option to meter only the higher usage points such as the tub/shower and the toilet to reduce the overall installation cost. Stacked riser plumbing systems are readily identified by a central boiler.