The Barracks Arch is located on the corner of Malcolm and Elder Streets, at the western end of St Georges Terrace in Perth, Western Australia.
Designed by Richard Roach Jewell, the Barracks were originally built from 1863 to 1866 to house the Enrolled Pensioner Force. The Enrolled Pensioner Force came to Australia as guards on convict ships, and were given small land grants in return for part-time guard work. The bulk of convict work moved from Fremantle to Perth in the 1860s, so there was a need to accommodate many Enrolled Pensioners and their families.
Architect Jewell designed the three-storey building in Tudor style that resembled a medieval castle. The building was brick, rather than more expensive stone, and horizontal lines emphasised by using lines of paler colour bricks underneath the windows. The roof was made of timber shingles. The building was finished in 1866, and was later extended to house an additional 21 families. Each family apartment had two rooms, each about 13 feet by 11 feet, with at least one fireplace. The outbuildings included a cookhouse, firing range and gun-room, wash-house, stores and stables, and a fives court constructed later.
A fire in 1887 destroyed the timber flooring of the east wing and the second floor of the central section. Water was pumped by hand pumps from the Swan River and brought by buckets through a chain of volunteers. The burnt sections were later restored.
The Barracks were gradually converted to offices for the Public Works Department between 1900 and 1904, becoming its headquarters in 1904. Notable occupants included C. Y. O'Connor, whose office was immediately above the arch. The fives court housed the drawing office, and eventually connected to a mid-1920s addition for the Metropolitan Water Supply, Sewerage and Drainage department. The Public Works Department and Metropolitan Water Board moved to Dumas House in March 1966.