[3] In April 1864, a design by Benjamin Backhouse was selected, but was later rejected after it was estimated that it would require £38,000 to construct, exceeding the maximum cost of £20,000 specified in the competition.

[5] However in November 1865, the commissioners withdrew their recommendation and resigned, following criticism by James Cowlishaw who claimed none of the submissions was satisfactory.

[6][7] In December 1864, Ellerker wrote a public complaint about the process,[8] but ultimately plans by Charles Tiffin, the Queensland Colonial Architect, were selected.

Amid controversy and allegations of undue influence on the outcome of the competition, Tiffin donated his prize money for the design to the Ipswich Grammar School.On 14 July 1865 the foundation stone for the building was laid by Sir George Bowen.

[10] In March 1939, the Speaker of the Legislative Assembly George Pollock committed suicide at his office in Parliament House by shooting himself with a shotgun.

[11] Led by George Gray, in August 1939 members of the League for Social Justice marched on Parliament House to protest unemployment, "armed with batons, coils of barbed wire and hammers".

[14] Alongside parliamentary and government offices, the Annexe also includes accommodation for regional MPs to stay in when in Brisbane.

The original zinc and galvanised iron roof was replaced in the 1980s with one constructed from sheet copper from Mount Isa.