The Victorian program recognises three replacement paths for a ducted gas heater, and the right one depends on the house rather than the discount.
Ducted reverse cycle is the like-for-like path: one fan coil in the roof, every room from ceiling outlets, zones on the controller. It suits most three and four bedroom homes with a usable roof space and is what our ducted reverse cycle page covers in detail.
A multi-split is one outdoor unit feeding wall heads in two to five rooms. Under the program every indoor unit has to come from the same manufacturer as the outdoor unit. It suits period homes with no roof space for a fan coil, homes where only some rooms need conditioning, and anyone who wants each room on its own remote. Our multi-head page explains it.
Four single splits, typically one larger head in the living area and three smaller ones in bedrooms, is the path when the outdoor units can be spread around the house and the walls are easy. It gives each room independence at the cost of more outdoor units.
On the call the office asks about the roof space, the rooms you actually use and the walls, and recommends one path. The discount differs between the three, and the office confirms the figure on the quote rather than on this page.