I think this is a new question, not a response to something else.
And I think it’s about SPs registered pre-1974.
For SPs registered pre-1-July-1974, it is true that:
1) Balcony doors are owner’s responsibility, but owners must still obey the By-Law about “in keeping with the rest of the building”.
2) With an SP of that vintage, if one balcony door needs maintenance or replacement, they probably all do, and it’s “permissable” for the OC to resolve to fix them all at once at OC expense, assuming each unit has the same number of balcony doors.
3) Garage doors are common property.
For exclusive use By-Laws registered pre-1987, it is true that:
4) Maintenance became the exclusive user’s responsibility, by default, without that fact having to be stated in the exclusive use By-Law.
5) It would be “unfair” to apply the principle in (2) above if not all units have an exclusive use garage.