It has been brought to my attention that the NSW Building Commission recently released correspondence to private certifiers and local Councils click here for link regarding the requirement for a compulsory geotechnical investigation. In case you didn’t want to click the link above, a screenshot image released by the NSW Building Commission is shown below.

While a geotechnical investigation and report is required under the National Construction Code and Australian Standards, I understand that private certifiers and local Councils are requesting a geotechnical report prior to issuing a Construction Certificate. Assumed classifications or advice from old reports is not being accepted. I recommend that you contact your certifier/Council for clarification.