The Snowy 2.0 project involves linking two existing dams, Tantangara and Talbingo, through 27 km of tunnels and building a new underground power station. Water will be pumped to the upper dam when there will be surplus renewable energy production, and the energy demand will be low and then released back to the lower dam to generate energy when the electricity demand is high. It will provide power while reusing the water in a closed loop and maximise the efficiency of other energy sources to pump water to the higher dam, which will be stored for later use. This paper focuses on the ventilation challenges, implementation, legislative requirements and planning on one of the sites, taking upfront designs into the execution phase with development and construction taking place before handover for long-term use. Lobs Hole consists of the two main tunnels, the Main Access Tunnel (MAT) and the Emergency Cable Ventilation Tunnel (ECVT), both developed by an 11 mØ Tunnel Boring Machine (TBM) that form the accesses to the two main powerhouse chambers developed by drill and blast techniques. These chambers, or ‘Halls’, will house the electric power station and turbines and will be two of the largest underground chambers in the world (60 mH × 30 mW × 250 mL).