Previous work by the authors has identified that the selection of supply air temperature control reset schedule has the potential to influence total HVAC energy use in Australian office buildings by up to 10%. This previous work has also identified a general but not uniform trend for lower supply air temperatures, which go hand-in-hand with lower airflows, to produce generally improved efficiency relative to high temperature high flow scenarios. However these results also indicated clear evidence that such a generalisation would not always produce the best outcomes. In this paper, the optimisation of supply air temperature control is considered in more detail using IES VE. Parameters investigated include the AHU configuration and zoning, reheat energy source, cooling energy source and the AHU load, across the temperate to subtropical climates represented by Melbourne, Sydney, Canberra and Brisbane. The results are used to generate more specific observations as to the optimisation of AHU supply air temperature controls with a view to providing better insight into the general programming of AHU controls in practice. The potential performance impacts of optimised alternatives are compared to the standard base case scenario to evaluate the potential of more comprehensive optimisation to generate additional efficiency relative to standard practice.