Optimizing steel usage in roof trusses is vital for reducing costs, enhancing sustainability and improving construction efficiency. This study aimed to investigate medium-span steel roof trusses with spans of 15, 20 and 25 m in Bengaluru, India. A comprehensive comparative analysis was conducted on different truss types—A-Truss (comprising Tube, Rectangular Hollow and Angle sections), Castellated Cellular Beam Truss and Plate Girder Truss, using Dlubal’s RSTAB software. The trusses were modelled under consistent boundary conditions for each span to ensure a valid comparison. The evaluation criteria included load-carrying capacity, deflection and steel quantity, with optimization techniques applied to minimize steel usage while fulfilling structural requirements. The findings revealed that the Cellular Beam truss demonstrated the least deflection and the highest structural efficiency. The Plate Girder truss, despite being lightweight, showed moderate deflections, whereas the Angle truss was the heaviest and least efficient. This research advances sustainable construction practices by optimizing steel utilization, improving resource efficiency and lowering carbon emissions, offering valuable guidance for engineers in designing cost-effective and robust steel roof systems.