Material needed to prepare contract of sale - NSW

I am wondering if in NSW we are planning to sell a house that is still being built (before completion) what material we need ready in order to form the contract of sale. It wont be off the plan as the completion time frame is within a few weeks.

Off the top of my head, I am thinking HWI, Subdivision Survey, Section 73, Section 88B etc to be put in a contract of sale.

A list of documents needed and how to get them would be appreciated.

 

s149 Certificate too

 

• Certificate of occupancy
• Water board/drainage diagram
• Survey (confirming that the house is correctly sited)

 

S149 will be readily available from previous contracts but I wonder if we can form a contract without having the OC and some of the other documents as the house is not fully completed as yet.

 

@Tenex - a new S149 is required (less than 3 months old)
Sewer diagram is also mandatory

The rest is optional but if buying new ...

 

All is optional however if not included there will be consequences such as purchaser being able to rescind up to certain dates