An interior shot of Australia's new portrait gallery. (Dragi Markovic/National Portrait Gallery)

A new National Portrait Gallery opens Thursday in the Australian capital of Canberra, a project 15 years in the making.

The portraits, part of a collection of 1,200 amassed since 1999, used to hang in Old Parliament House in Canberra.

But only 130 paintings could be displayed at any one time, while the new gallery has space for 450.

Designed by architect Richard Johnson, it is a single-storey concrete building with simple galleries lit by natural light.

The design incorporates, wood, stone and plants from every region of Australia, including sandstone from Sydney and bluestone from Victoria.

"This is a contemporary building and it loves contemporary art. Old Parliament House was a historic building and lots of the historic works looked well in there but many of the contemporary pieces clashed with the carpet and so on," said director Andrew Sayers.

"This building also has much greater opportunity for us to show sculpture … and to have much more material in showcases," he said.

When the gallery opens, viewers will see colonial era portraits alongside photographs of the late "Crocodile Hunter" Steve Irwin and multimedia moving images of Oscar-winning actress Cate Blanchett.

'Fabric of Australian culture'

"It allows us to bring together many more people in a particular area or field, so we have whole walls of musicians, whole walls of politicians, whole walls of writers and artists," Sayers said.

"It's only when you get that richness of texture that you can start to tease out some of the fabric of Australian culture."

Sayers said the gallery will present both heroes of Australian history and contemporary figures.

"So primarily I would really like people to leave knowing something they didn't know, but also feeling our society and our history is something that is much more complicated and that we all have something in our own lives that we can contribute," he said

The new portrait gallery cost $70 million, $16 million more than expected. It sits beside a lake in the area that is home to most of Australia's federal government buildings, including the High Court of Australia and the National Gallery.

Australia has created interest in the new gallery with an online exhibition of popular Australians and unsung heroes.

The 30 video portraits being shown were chosen in a national competition launched by the gallery and the Australian Broadcasting Corporation.

Olivia Newton John has the No. 1 spot in the My Favourite Australian contest, followed by TV personality Peter Cundall and singer John Farnham.

Sayers said it was surprising that statesmen such as former prime minister John Howard and Tasmanian politician Bob Brown were chosen rather than sporting heroes.

"The recent past is much more compelling for people than the distant past," he said.

"Figures in history never really figure in people's imaginations when they're trying to think about who are the most important Australians — they are people from the recent past or from the present."

The Harper government recently cancelled Canada's plans for a National Portrait Gallery. Canada has a collection of more than one million portraits and photographs, being held now by Library and Archives Canada, but seldom seen by the public.

With files from the Australian Broadcasting Corp.