Abstract: A multi-level building has a water supply pipe extending upwardly through all levels. A closed chamber at each level receives water from the supply pipe at a position below the top of the chamber to trap and pressurize air therein. A plurality of distribution pipes extend from at least one end of each chamber to points of use at that level of the building. In one form the water pipe extends vertically through the chamber and in another form the chamber and water pipe are separate.