Page "Parliament of Australia" Paragraph 19

In the event of conflict between the two Houses over the final form of legislation, the Constitution provides for a simultaneous dissolution of both Houses – known as a double dissolution.

If the conflict continues after such an election, the governor-general may convene a joint sitting of both Houses to consider the disputed legislation.

This has occurred only once, after the election following the 1974 double dissolution.

However, there are other occasions when the two houses meet as one: see Joint meetings of the Australian Parliament.