Thanks for your question, Maree.
Parliament House was built with around 4 500 rooms. This includes the large rooms for the Senate and the House of Representatives, along with offices for members of Parliament and their staff, parliamentary officers (who help with the work and security of the Parliament), and the media. There are also numerous meeting and committee rooms.
While there have been minor modifications since the building opened in 1988, the overall number of rooms has not changed.