Hi Greens & Mattb,
Sorry to say, but your incorrect in your interpretation regarding balconies.
The air space of a balcony is typically part of the lot. You need to refer to the strata plan in this regard, but mostly you will notice the veniculum reflecting that the balcony is attached to the lot.
The structure of the balcony is considered to be common property, and I guess there is an argument of chicken and egg in this situation. It does sound like there is a bit of a design flaw with the current arrangement and it would be in the OC’s interest to rectify this situation, however it could be argued that some of this work is an improvement to common property, and requires a special resolution at a general meeting, but this is a matter of interpretation.
Mr S