Buy now build later
You can buy a block of land and build on it at a later date. It could give you an opportunity to save money and have a reduced mortgage by the time it comes to build.
Make sure that the land is suitable for residential development and that the contract doesn't have a conditional clause stipulating a date by which building must either start or be completed.
You will need to pay annual service fees for the land even if construction hasn't begun. These include council rates and water and sewerage fees. For more information about service fees contact the local council and SA Water.