There seems to be a mix-up here between WHS (Workplace Health and Safety laws) and building regulations and standards set by the NCC (National Construction Code, formerly the Building Code of Australia).
Unless legislation requires it, existing buildings do not have to be compliant with the latest NCC standards. They only need to be complaint with the standards that existed at the time they were built. Some areas like fire and window safety have been legislated, so buildings must be compliant in those areas according to the law.
WHS is a different matter.
All states and territories, except Victoria and WA, have adopted the Commonwealth Occupational Health and Safety Act in their State Acts.
So both in the Commonwealth and NSW WORK HEALTH AND SAFETY REGULATION 2011 – REG 7 it states:
7 Meaning of “person conducting a business or undertaking”-persons excluded
(1) For the purposes of section 5 (6) of the Act, a strata title body corporate that is responsible for any common areas used only for residential purposes may be taken not to be a person conducting a business or undertaking in relation to those premises.
(2) Subclause (1) does not apply if the strata title body corporate engages any worker as an employee.
Very few OC/BCs have actual employees so they are usually exempt from their WHS Acts. Cleaners, gardeners, tradespeople etc that do paid work for an OC/BC are usually not considered to be employees.
Even in Victoria, which hasn’t adopted the Commonwealth Act, a residential strata that does not engage a worker as an employee is exempt. This information was given to me directly from Worksafe Victoria.