You will receive 2 contracts, one for the land purchase, and one for the building.
Once you have signed these contracts, you will normally have a ‘subject to finance’ clause of between 14 and 21 days which commences the day the vendor signs the contracts. A subject to finance clause means that you have the 14 or 21 days to obtain unconditional approval for your loan from a lender.
If for whatever reason you do not obtain suitable finance, you can usually rescind the contract and have your $1,000 holding deposit refunded.