The Allgas Building, a two-storeyed building in what was formerly central Stanley Street, was erected in 1885 for the drapery and outfitting firm of Allan & Stark. It was built during the peak of South Brisbane commercial development and the reconstruction of Stanley Street premises, and was a reflection of boom era confidence.

Along with a number of prominent South Brisbane firms, Allan & Stark moved across the river to higher ground after the disastrous floods of 1893. Caledonian House was leased to the Queensland National Bank as a branch office [301 Stanley Street] in August 1897, and the South Brisbane Gas & Light Co. Ltd sub-leased a section [305 Stanley Street] from October 1897.

In 1909 the QNB purchased the building for £2,500, with the South Brisbane Gas & Light Co. maintaining its office and showroom there.

Alterations, including changes to the street frontage, were carried out in 1931 under architects Hall and Phillips, and included the erection of an awning and alterations to the shop front. The building was again extended in 1942.

In 1943 the branch was closed as a war time economy, and 301 Stanley Street was leased to shirt and pyjama manufacturer Alfred Portrate until 1949.

The corner premises were reoccupied by maintenance staff of the National Bank of Australasia in 1949. In 1965 it was purchased by the South Brisbane Gas & Light Co. Ltd [Allgas Energy Ltd from 1971].

In 1984 the building was resumed by the Expo Authority, renamed Central House, and functioned once again as a bank during World Expo '88. It also housed the Picasso Restaurant.

The building was again refurbished in 1991 as part of the Southbank redevelopment, and now operates as an administration centre.

Little remains of the original interior of the building. Externally, the northern facade remains intact above ground floor; the ground floor facade has been modified a number of times throughout the life of the building.