The building, in the neo-Palladian style of the neoclassical movement, was built as the Front Soldiers' Barracks in 1882–1884 to designs by Italian architect Joachim Grassi.

[1] The building is designed in neo-Palladian style, following a three-storey rectangular floor plan with a central courtyard, built of masonry with load-bearing walls.

The façade, facing west towards the Grand Palace, is marked by a central pediment supported by Doric-order columns, which is flanked by two wings with gates leading into the courtyard.

It is surrounded by streets on all sides (Sanam Chai to the west, Lak Mueang to the north, Rachini to the east, and Kanlayana Maitri to the south).

According to the original plans, the central structure was to contain an armoury and military museum on the top floor, officer's meeting rooms on the middle, and sword-fighting practice areas below.

At the rear of the south wing was a connected clock tower (since removed), which also housed water pumps and storage tanks—the building was built with metal plumbing.

[4] The building has undergone several additions, including an extended portico at the front,[1] a new section running alongside the original northern wing, and annexes at the rear (east side) of the complex,[5] where a granary and bathing and swimming pools used to be located.