Going back to the original question – WHS applies to workplaces, so if anchorage’s scheme does not have employees on site, and the scheme is purely residential, then the advice that it is legally compulsory to have an inspection is incorrect.
Non-residential means non-residential, i.e. for some other use such as commercial premises.
More generally – an OC has a general responsibility to keep the premises safe. For example if a hole opens up in a pathway, or it becomes clear that some steps are unsafe, then it should take steps to fix the problem. If it does not, then it may find it is liable for an injury suffered by an occupant or a visitor. That is not a responsibility under the Work Health and Safety Act, it is a more general legal principle.
There have been cases on the OC responsibility to keep the premises safe, which centre around section 62. A well-known one is Ridis, where the plaintiff failed in his action against the OC at Court of Appeal level.