I am about to contradict myself. This is what the SCA’s “Who’s Responsible ..” document (prepared by the Dept of Lands) says:
If the strata plan was registered before 1 July 1974 the balcony wall including the windows and door and their working parts are generally part of the lot and the lot owner’s responsibility for maintenance and repairs (unless there is a notation on the strata plan or the balconies are not shown on the strata plan).
If the plan was registered after 1 July 1974 the balcony wall including the windows and doors and their working parts are generally common property and the owners corporation’s responsibility (unless the strata plan says otherwise). With the exception to flyscreens and/or security doors where they were installed by an owner after registration of the strata plan.
Looks like your strata manager is right. This is not the law, per se, but it would certainly be used as a guide at a tribunal. Maybe you won’t have your neighbour dropping in after all.