This seems to be different in Victoria where the OC Act states:
129 Care of lots
A lot owner must—
(a) properly maintain in a state of good and serviceable repair any part of the lot that affects the outward appearance of the lot or the use or enjoyment of other lots or the common property; and
(b) maintain any service that serves that lot exclusively.
Re ” maintain any service that serves that lot exclusively”. As far as I know the service can exist anywhere including on Common Property. The lot owner must still repair and maintain it.