(1) Air admittance valves shall only be used to vent,
(a) fixtures in buildings undergoing renovation, and
(b) installations where connection to a vent may not be practical.
(2) The air admittance valves shall be located,
(a) above the flood level rim of the fixture it serves,
(b) within the maximum developed length permitted for the vent,
(c) not less than 150 mm above insulation materials, and
(d) installed in a location not subject to back pressure.
(3) Air admittance valves shall,
(a) only vent fixtures located on the same storey, and
(b) be connected to the horizontal fixture drain.