Net zero energy buildings (NZEB) in Australia can save a lot of energy by making simple changes like using better windows, adjusting lighting, and setting comfort levels right. Two NZEBs and a regular commercial building were studied, and the NZEBs showed bigger energy savings potential. By choosing the right materials and controlling lighting and comfort settings, both NZEBs and regular buildings can save a significant amount of energy. This study proves that small changes in design can make a big difference in energy efficiency.