A Japanese architectural group has been announced today as the firm that will work with the Art Gallery of New South Wales on its major expansion, known as the Sydney Modern project.

The Tokyo-based practice, SANAA, was selected by an international jury from a shortlist of five architects to work on the $450 million project for the landmark new building.

SANAA was founded 20 years ago in Tokyo by renowned architects Kazuyo Sejima and Ryue Nishizawa. Their award-winning work includes Manhattan’s New Museum of Contemporary Art building and the Musée du Louvre-Lens in northern France.

In 2010 the duo was awarded the Pritzker Architecture Prize, architecture’s highest honour.

Their winning concept for the AGNSW expansion is a series of light-filled pavilions designed to blend with the Botanic Gardens, the Domain and Sydney Harbour.

“The SANAA concept is at once subtle and spectacular in its design. It responds to and respects the extraordinary beauty of the competition site through a series of pavilions that reach out to [the surrounding areas],” says AGNSW director Michael Brand.

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“The subtle profile of the pavilions complement and preserve the history of the existing gallery building, creating spaces that bring people together and foster a sense of community, imagination and openness.”

SANAA will partner with a local architectural firm to realise its final design for Sydney Modern.

Kazuyo Sejima is one of the most highly regarded architects in the world. She says she is thrilled to be working with the gallery on this important next step.

“I am very much looking forward to learning more about the history, collection and diverse environment to develop the design into one that is fitting to this beautiful landscape,” she says.

SANAA’s concept was selected unanimously by the international jury from a shortlist of five architects that included Australian firms Kerry Hill Architects and Sean Goodsell Architects and two other international firms.

Jury member Juhani Pallasmaa, a Finnish architect and professor, says the Sydney Modern Project jury was impressed by SANAA’s design, which subtly incorporates the various urban and landscape components of the site.

“The complex of pavilion-like units does not dominate the site, or attempt to project its own overwhelming architectural image. It creates a respectful, refined and balanced dialogue with the existing gallery building, as well as the larger park setting,” Professor Pallasmaa says.

The final concept will be developed over the next 12 months along with staff, relevant groups and the broader community.

It is hoped the Sydney Modern project will be completed by 2021 in time for the gallery’s 150th anniversary.