if, according to the Strata Manager, the balcony “airspace” isn’t common property and in fact part of the lot itself, then Section 153 definitely applies.
True. But the balcony air space IS common property, only with exclusive use by the resident of the unit. Your assessment of his professional commitment sounds spot-on.
I don’t mean to be difficult but that doesn’t seem right to me.
AFAIK the airspace on an apartment lot balcony is the same as the airspace inside a an apartment lot.
The balcony structure will be common property the same as the floor structure inside the lot is. But the airspace belongs to the lot with boundaries defined on the strata plan.