English: In 1874 a Commission was appointed by the Governor to inquire into and report on the designs submitted in competition for the new Parliament Houses and a successful design was chosen. It was decided to use local material - marble from Kapunda and granite from West Island (near Victor Harbor) - for the building. Work began on the current site, immediately east of the then existing House, and was completed in 1889.
The question of the completion of the eastern wing of the new Parliament House was raised on a number of occasions over the years, but it was not until 1913 that sketch plans were prepared by the Architect-in-Chief's Department for this project. These sketches were approved by a Joint Committee of both Houses, but the work was delayed following the outbreak of World War I.
Parliament House as it stands today was eventually completed to commemorate the centenary of the State. The project also functioned to provide hundreds of people with work during the Depression. Towards this end, the Hon. Sir J. Langdon Bonython, K.C.M.G., one of the State's greatest benefactors, made the gift of £100,000. Plans for the completion of the building were drawn up in 1934, altered slightly from the scheme which had been approved by the Joint Committee in 1913.
Work on the new wing commenced in March of the State's centenary year, 1936. To harmonise with the 1889 wing, West Island granite and Kapunda marble were again used.