http://www.campbelltown.nsw.gov.au/upload/ddboe49399/zoningweb.pdf
Bit more of a general explanation for you. This is for Campbelltown but similarly applies elsewhere. One of the keys to remember, is that if you can get a complying development application through a suitably qualified town planner and he/she is able to extract the absolute maximum use for your property, then there is relatively more chance of success than trying to drive your application directly through council.....just food for thought.
Perhaps do some searching of posts by Aaron Sice on this topic & more.
Cheers,
Ian.