maybe in the wrong section but...
without opening the usual can of worms....
cabling: can an owner builder do their own cabling for the ducted vacuum???it is usually 24volt - just for the switches at the end of the openings where the vacumm hose plugs in( it means that the vacuum switches on when the hose is plugged in)??? its probably another AUSTRALIAN GREY AREA.....
If not - is it the electricians job or a cablers job....