Has the land been approved to subdivide? The thing is, to subdivide, it costs a FORTUNE. All of the local council, and state government fees can cost tens of thousands of dollars. If the current land owner has already gone though this process, you are ok, but if not, it could make it very expensive to subdivide.

Have a look into the town planning records for that particular block.
Yeah that too - I wasn't sure if you had already covered off on that. In some cases the council may have already determined that all blocks in a certain area are to remain a certain size and they can't be subdivided further - they are generally covered by town planning schemes and should be available for you o check.