[whynot]

Putting my sparkie's hat on ... the tricky bit is not the cost or the installation difficulty of the final circuit (be that 15A, 20A, or 32A). The tricky bit is recalculating the impact on the installation's maximum demand calculation and the subsequent impact on the correct sizing of the consumers mains (the wiring from the overhead pole or underground pillar to the switchboard).

Most houses pre-1976 standard, particularly if they had gas cooking and heating, were wired with 6mm2 consumer's mains. This size wiring has a rating of 32 amps.

More common practice up until recently is for consumer's mains to be wired in 16mm2 cable, with a rating of 63 amps. A typical maximum demand calculation for a home with electric heating and cooking would be somewhere around 50 amps.

In the latest edition of AS3000 (which, by law is the definitive document on wiring rules) an electric vehicle's contribution to maximum demand is taken at 100% load.

Depending on the exiting maximum demand calculation, a dedicated EV connection point can easily push the maximum demand calculation beyond the rating of the existing consumers mains and the rating of the existing switchboard.

Uprating both (switchboard and consumer mains) could be big dollars. But, as the saying presently goes ... if you can afford an EV, you can also afford a switchboard upgrade. It is really a case by case basis that requires a site visit by an electrician.

Not trying to put people off an EV, but it is worth something checking out if you are thinking about installing a charger larger than 2.3kW.