The powerhouse drew on water from the three main dams and various other inlets on the scheme (see separate records) to drive five 6,800 kW generators. These were set into a deep rock excavation to get the turbines as close to sea level as possible. Lochaber power scheme was a significant development in terms of scale and innovation over the previous BAC scheme at Kinlochleven. The output from the powerhouse was not exceeded until 1950 at Sloy. The powerhouse is on a large scale with a number of good design features including a pilastered rear elevation, mural panels and corbelled band courses. The powerhouse forms part of one of the most significant engineering projects of the twentieth century, using water from Laggan, Spey and Treig reservoirs which is piped under the flanks of Ben Nevis.