When purchasing land, yes, you do have to do your independent due diligence. Further, there is no "one-stop shopping" for all the information you need.This white paper lays out the steps of California due diligence and reporting to clarify the holder's responsibility. A real estate due diligence checklist is also a closing checklist. Therefore, use it to keep on top of each phase of a real estate transaction. The timeframe for completing the buyer's due diligence in a CAR Residential Purchase Agreement is specified in the contract.