This study investigated the impact on predicted energy consumption of recommended values for occupant-influenced loads from four simulation protocols for Australian office buildings. Three guides currently in use in Australia, and the ASHRAE 90.1 Appendix G protocol were examined. Recommended values and schedules vary across the protocols, and the is a need to harmonize the inputs for consistency. The default occupancy inputs from these protocols are often used in building performance simulation studies in Australia, and this may introduce an unnecessary uncertainty. BPS on a reference office building in Sydney and Melbourne, and a detailed case study building in Sydney was used to investigate the impact of protocol selection. It was found that the selection of simulation protocol can result in building energy use predictions varying by up to 13.5%, and substantially different load breakdowns.