If you are non-resident in Australia and not an Australian citizen you will generally require the pre-approval of the Foreign Investment Review Board. It is the responsibility of the purchaser to inquire if any approval is required.
Please refer to your Solicitor or the FIRB web site for further clarification. In particular the following locations are of particular use http://www.firb.gov.au/content/_downloads/policysummary.pdf and http://www.firb.gov.au/content/_downloads/urbanpolicy.pdf . Also of interest is http://www.firb.gov.au/content/_downloads/off_the_plan.pdf , although this last one is more for those with an interest in development.
The following is an indicative overview of the current position – though you should receive advice on your specific situation from a solicitor before proceeding;
Non-Residential Commercial Property • No approval required for purchase of non-residential commercial property of an amount not exceeding $50,000,000.
Residential Property • Formal approval required for any purchase of residential property whether this is vacant land or a dwelling.
Applications to purchase are processed free of charge by the FIRB and can be downloaded from their web site. Processing your request can take anywhere 10 to 21 days.