Jorn Utzon, an architect who designed one of the world’s most recognizable buildings — the Sydney Opera House — but never saw it finished, died in Copenhagen on Saturday. He was 90.

He died of heart failure in his sleep, according to his son Kim.

Utzon left Australia amid controversy seven years before the Opera House was completed. He lived out most of his final decades on the Spanish island of Majorca, while his gull-roofed building came to symbolize Australia, 10,000 miles away.

As a young architect, Utzon worked for Gunnar Asplund in Sweden and Alvar Aalto in Finland before establishing his own practice in Copenhagen in 1950. In 1956, he read about the Sydney Opera House competition in a Swedish architecture magazine. He spent six months designing a building with sail-like roofs, their geometry, he said, derived from the sections of an orange. Utzon’s plan was championed by Eero Saarinen, the Finnish architect who was one of the judges in the competition.

In 1957, Utzon — who until then was hardly known outside his native country — was declared the winner, and for the next five years he worked on the project from his office in Denmark. In 1962, he moved with his wife, Lis, sons Jan and Kim, and daughter, Lin, to Sydney.

When only the shell of the opera house was complete, the architect found himself at odds with Davis Hughes, the New South Wales minister for public works, over cost overruns and delays. When Hughes stopped payments to Utzon in 1966, the architect packed up his family and left the country.

Supporters of Utzon said that an unreasonably low construction estimate made it seem as though costs had escalated far more than they had, and that he had been treated unfairly.

Writing in Harvard Design Magazine in 2005, Bent Flyvbjerg, a professor of planning at Aalborg University in Denmark, argued that “the real loss in the Sydney Opera House project is not the huge cost overrun in itself. It is that the overrun and the controversy it created kept Utzon from building more masterpieces.”

In recent years, Australian organizations tried to heal the breach. In 2002, Utzon was commissioned to design interior renovations that would bring the building closer to his original vision; his son Jan, who is also an architect, traveled to Australia to carry out the work. And in 2003, Utzon received an honorary doctorate from the University of Sydney. (Jan took his place at the ceremony.)

The same year, Utzon won the Pritzker Prize, considered architecture’s highest honor. Frank Gehry, who was a Pritzker juror at the time, said that Utzon “made a building well ahead of its time, far ahead of available technology, and he persevered through extraordinary malicious publicity and negative criticism to build a building that changed the image of an entire country.”

Jorn Utzon, the son of a naval architect, was born in Aalborg, Denmark, on April 9, 1918. He studied architecture at the Royal Academy in Copenhagen. After leaving Australia, he worked in Hawaii, Switzerland and Spain before settling in Majorca in the mid-1970s. In addition to the Sydney Opera House, he designed the National Assembly of Kuwait, a church in Bagsvaerd, Denmark, and many private homes, including two in Majorca for himself and his wife. He chose the spot for the first house, he said, because it reminded him of the Australian beachfront he had hurriedly departed.

Though he suffered from failing eyesight in his final years, he continued to discuss architecture and could visualize plans the way a chess player can visualize a board, Jan Utzon said.

When he was accepting the honorary doctorate in 2003, Jan Utzon said the fact that his father had never visited the opera house did not mean he had not experienced the building. “As its creator, he just has to close his eyes to see it,” he said.