Given the challenges to design Net Zero Energy Buildings (NZEBs), the use of Building Performance Simulation (BPS) tools during early design phases has been indispensable. In this context, we compare ten early design BPS tools. The aim is to define the potential of using and integrating the tools by architect during the design of NZEBs. The examined tools include HEED, e-Quest, ENERGY-10, Vasari, Solar Shoebox, Open Studio Plug-in, IES-VE- Ware, DesignBuilder, ECOTECT and BEopt. The comparison is based on two different criteria sets. The results describe tools limitations and major requirements to meet the NZEBs objective implications. ; Peer reviewed