The building is know as the Occidental Substation, it was built by the Los Angeles Pacific in the late 1890s when they pushed through the line to Santa Monica via Hollywood. They made the various cuts that Sunset passes through with mule teams and steam shovels. The building housed equipment to convert high voltage AC power from Edison or DWP to 600v DC that the trolleys ran on. Another similar building by the same company is located at the very edge of Culver City at Exposition and Venice Blvds.
--John Heller, vice president
Electric Railway Historical Association of Southern Califorinia