A design studio behind New York City's famous elevated linear park The High Line has been named the joint winner of an international competition to design Adelaide's new arts and cultural hub.

Arts South Australia has announced that a joint entry from Diller Scofidio + Renfro — also responsible for a recent expansion at New York's Museum of Modern Art — and Adelaide company Woods Bagot are the winners of the Adelaide Contemporary International Design Competition.

It was a global search for a team to design a new arts and cultural destination on the former Royal Adelaide Hospital site on North Terrace.

Woods Bagot is also responsible for the SAHMRI building and the Adelaide Convention Centre. It described its concept as a "dynamic, people-friendly place with an expertly designed gallery".

The winning company also designed The High Line elevated greenway in Manhattan, New York City. ( Wikimedia Commons: Beyond My Ken )

Design features include a ground floor "super lobby", nine gallery spaces, floating top-floor sky galleries and a suspended rooftop garden.

Local flora, present before South Australia's colonisation, will feature in the garden as a nod to the Kaurna people's concept of Minkunthi — meaning "to relax".

Diller Scofidio + Renfro partner Charles Renfro said the design is aimed at "celebrating the city's world-class cultural offerings — from its vibrant festival scene, to its diverse art collection, distinguished by its outstanding holdings of Aboriginal work".

"Our approach will coalesce museum, city and gardens into a new arts centre that welcomes everyone, that provides a curatorial tool box which anticipates the future of culture," Mr Renfro said.

Inside the proposed art gallery building. ( Supplied: Diller Scofidio + Renfro and Woods Bagot )

"The new gallery and public sculpture park is envisaged as one of the most significant new arts initiatives of 21st century Australia, providing a national focal point for Aboriginal and Torres Strait Islander art and cultures as well as new spaces for major exhibitions, and the opportunity to unlock the hidden treasures of South Australia's state collections."

Woods Bagot's chief executive officer Nik Karalis called the winning joint entry "a magnificent example of international collaboration".

"Adelaide Contemporary will be a key cultural institution for the state of South Australia, and we're thrilled to bring this relationship to a project of such significance," Mr Karalis said.

The competition, organised by architectural competition firm Malcolm Reading Consultants, ran in two stages from 2017, attracting expressions of interest from 107 design teams from more than 525 global firms.

Six teams were shortlisted to produce concept designs, which were then judged by an international jury of nine people.

All six finalists' concept designs are on exhibit at the Art Gallery of South Australia until June 11.

A large, open space features prominently inside the planned gallery building. ( Supplied: Diller Scofidio + Renfro and Woods Bagot )

The estimated project budget is $250 million, which needs final funding approval from the Government of South Australia.

Upon its launch, the project was championed by the state Labor government, but the current Liberal Government has hit pause on gallery plans.

The Liberal party went to the March state election promising to develop a national Aboriginal art and culture gallery, whereas Labor promised a contemporary art gallery.

In late May, Premier Steven Marshall said he was negotiating with the state's key cultural institutions — the Art Gallery of SA, the SA Museum and Tandanya — about what form the gallery will take.