Joern Utzon, Opera House architect, dies at 90

The Danish architect of Australia's iconic Sydney Opera House, Joern Utzon, has died aged 90.

Utzon died from a heart attack in his sleep early yesterday. He was surrounded by family members in Denmark, his son, Kim Utzon, told Associated Press.

`He had not been doing well these past few days, since Thursday. He had been undergoing a series of operations recently," he said.

Utzon created the first designs for Sydney's Opera House in 1957 but never returned to Australia after leaving in 1966, nearly seven years before his internationally acclaimed building was finished.

In 2003, he was awarded the prestigious Pritzker prize for architecture. The jury singled out the Opera House as one of the most iconic buildings of the 20th Century, arguing it "proves that the marvellous and seemingly impossible in architecture can be achieved".

Prime Minister Kevin Rudd today paid tribute to the "visionary" architect.

"Joern Utzon was a visionary architect whose legacy includes one of the world's most spectacular and inspiring buildings, the Sydney Opera House," Mr Rudd said in a statement.

"Standing proudly on the edge of Sydney Harbour, the Opera House is one of the most internationally recognised symbols of our nation."

Utzon drew up the design for the Opera House in 1957 but quit seven years before it was finished after scandals about cost blowouts and design arguments. Government-appointed architects took over and the interior was not completed to Utzon's original plan.

Opera House Trust chairman Kim Williams said the famous building would dim its lights tonight as a sign of respect.

"Joern Utzon was an architectural and creative genius who gave Australia and the world a great gift," Mr Williams said in a statement.

"Sydney Opera House is core to our national cultural identity and a source of great pride to all Australians.

"It has become the most globally recognised symbol of our country."

A member of the pantheon of the 20th Century's architectural greats, Utzon was haunted - but insisted he was not embittered - by the disastrous end of his relationship with Sydney and what has become the city's harbourside symbol.

He declined invitations to return to Australia but has collaborated from afar on the most recent plans to alleviate the building's space and acoustics problems.

Born in Copenhagen in 1918, Utzon graduated from the capital's academy of arts in 1942, working in several major Danish architectural offices and later with Alvar Aalto in Finland. He established his own practice in Copenhagen in 1950.

Utzon's earliest buildings were private homes. His winning the design competition for the Opera House in 1956 was a surprise to many colleagues.

Utzon also designed the national assembly building in Kuwait City which was built between 1971 and 1983 and resembles a series of large tents, evoking the traditional meeting places of the Bedouin nomads.

Utzon lived in Mallorca, off Spain's eastern coast. He worked in partnership on several projects including a church that opened in 1976 in Bagsvaerd, a Copenhagen suburb and more recently consulting on the Opera House refurbishments.

Utzon was awarded the Order of Australia in 1985 and the Sonning prize for contributing to European culture in 1988.

He is survived by his wife Lis and their three children, Kim, Jan and Lin, and several grandchildren.