A report released on Thursday by accounting firm Deloitte has valued the Sydney Opera House at 4.4 billion U.S. dollars, an increase of more than 1 billion U.S. dollars since their previous assessment five years ago.

The company said that while it is difficult to put a price tag on a national icon, the economic value that the Opera House delivers to Australia is tangible, and is a sizeable return on the 73 million U.S. dollars it cost to construct.

With 10.9 million visitors every year, the Opera House is one of the world's busiest performing arts centers and employees 8,698 people to keep it running.

"If this were a company represented on the Australia Stock Exchange it would be one of the biggest in the country," report author John O'Mahony said.

The report put the past years' rapid increase in visitors and profit down to a number of factors, including growing number of international visitors to Sydney, an enhanced tour and performance experience, building renewal works, population growth, and a possible wider appreciation of the arts in Australia.

And with events such as New Year's Eve, the Australia Day, Vivid, and the Invictus Games beaming the iconic white sails on screens around the world, the hype is unlikely to subside.

"We can ensure Australians the brand value is incredibly high and remains up there with the Taj Mahal and the Great Wall of China as one of the world's most recognized buildings," O'Mahony said.