Tabita Gabriela Siagian

Lonsum building is one of PT. London Sumatera Indonesia Plantation Company ( LPSI ). This building was founded in 1910. At first the Lonsum building was the office of the Harrison and Crosfield rubber plantation companies. In 1982, the H&C company sold shares to the Sime Derby company. Then in 1994 Sime Derby sold all plantation assets to the London Sumatera company. The London Sumatera Company is a company engaged in the oil palm and chili plantation industry. The company was founded on 18 December 1962 and was actively operating in 1962.

The Lonsum Building is painted white on the outside. Because this building is a colonial building, it was designed in the style of a European house in the 18-19 century. This building is also equipped with an elevator , and is the first building with an elevator in Medan. The shape of the building used and the shape of the windows and doors are also made the same as in London. The window shape in this building is curved and uses large glass as the window. And there are also several pillars at the front of the building.