Allocating rewiring costs and seeking mediation

Context: small block of 6 apartments; interwar

Scenario: one of the apartments needs to be rewired; the electrician describes the issue as one of cotton insulation breaking down and causing nuisance tripping and power faults. (It’s also my understanding that at least some of the wiring in that apartment is not chased into the walls but is running along architraves and skirting boards.) No one is questioning the need for the work to be done.

The owner of the apartment has obtained a quote that includes rewiring all circuits, replacing all light switches and power points, possible chasing and conduit works and replacing the smoke alarms. The quote doesn’t specify which elements of the rewiring would involve common property and which not.

The strata manager on behalf of the SC/OC (all six owners are members of the SC) has obtained a quote that includes full rewiring and specifies running cable from the main board, as well as replacing the smoke alarm; identifies the likely need for chasing or external duct work. This quote itemises a division of cost between internal and external/common.

The other owners and I are agreeable to a splitting of the cost between the OC and the apartment owner based on this second quote. As I understand it, this is right and appropriate based on information I’ve found in a document from the NSW Office of Fair Trading as well as the SCA’s “Who’s Responsible” publication, which I found quoted here on a previous search.

But the apartment owner believes that the OC should be paying for the job in its entirety “because the electrical system is in the common area”.

The owner has requested a Fair Trading mediation meeting.
(This meeting was requested before anyone else in the SC was even aware of the need for rewiring, i.e. the owner at that stage had been in contact only with the strata manager.)

I could understand the apartment owner wanting to negotiate around the exact cost of each portion (internal vs common) and/or to want a third quote along those lines, but that hasn’t been their strategy. They are simply claiming that the electrical system is [entirely] in the common area and that the OC pay the full cost. These claims seem unsustainable to me. (And yet the apartment owner has, to date, struck me as an astute and knowledgeable person, shrewd even, when it comes to matters arising in our building…)

Given that it seems to be quite clearly set out as to who is responsible for what in a scenario like this, is it realistic for the apartment owner to expect that the Fair Trading mediation meeting will result in the OC agreeing – or being advised – to pay the full cost of the rewiring? What should we, the other owners, be prepared for?

Thoughts? Advice?

[Apologies if this topic has been raised in some form previously: the forum search box isn’t working at present (can’t click in it, and have tried both Chrome and Safari).]