DaveB said:
Whilst I have no problem with Jimmy's answer, I'd take a punt and say the annual charge is for the CHU Insurance premium.
D'Oh! I didn't make the connection with Corporate Home Unit and CHU (or Corporate Home Unit Underwriting Agencies Pty, to give it its Sunday name).
By the way, Darryln, insuring the building is one of the few statutory obligations that an Owners Corporation has, alongside maintaining common property and having an AGM.