The bible on this, the SCA’s ‘Who’s Responsible’ document says this:
Any pipe, cable, ducting, plug or the like that is for the exclusive use of the lot, then if it breaks:
- Within the lot – Owners responsibility
- Outside the lot or in a wall, floor or ceiling that abuts to either common property or another lot – Owners Corporation responsibility
That means that any wiring inside an external wall, ceiling or floor, is Owners Corp responsibility and any thing outside the wall (such as a socket) or in an internal wall that doesn’t adjoin common property or another lot is the lot owner’s responsibility.