It is a requirement under the National Construction Code to interconnect smoke alarms installed in residential buildings constructed after 30 April 2015. This requirement also applies to smoke alarms installed in extensions to existing dwellings.
There is no requirement to interconnect new smoke alarms that are installed in dwellings built prior to 30 April 2015, or when replacing existing smoke alarms in these properties.
The interconnection can be achieved either by hard wire interconnection or by wireless interconnection. It should be noted that when installing hard wired interconnected smoke alarms, the smoke alarms must be connected to the same circuit. In addition to this, the manufacturer may have limitations regarding the number of alarms that can be interconnected and the distance between interconnected alarms.