The Sydney Opera House: a father and son enterprise

In 1966 Jÿrn Utzon was forced to quit as architect of the Sydney Opera House before it was complete. Next week, the first new interiors he and his son have designed will be revealed. Louis Jebb reports

It is a story of rare poetic justice: Jørn Utzon, architect of the Sydney Opera House, one of the most famous buildings in the world, is being invited to finish his masterpiece more than 30 years after political opposition and press antagonism drove him to resign with only its exterior complete.

When Mr Utzon left Australia in 1966 to return to his native Denmark, the commission had already been handed over to an Australian practice. Working to a revised brief, the new firm took seven years to fit out interiors which have never lived up to the sculptural promise of the opera house's exterior - that otherworldly sequence of giant white sails that seem to roll and fold, one out of each other, providing an unforgettable landmark in the heart of Sydney harbour.

In 1998, the opera house committee approached Mr Utzon, then in his early eighties, and asked him to return to his greatest project and to come up with guidelines for the future of the building. They were anxious to bring some of the building's exterior "magic" to its interiors, but also to receive a manual from Utzon of his intentions - of how he wished later generations to approach the building's restoration and redevelopment. Mr Utzon felt too old to travel to Australia and asked that Jan, the elder of his architect sons and a long-time collaborator with his father, should be brought on to the project.

The Utzons, father and son, started work on the guidelines with a leading Sydney architect, Richard Johnson of JohnsonPiltonWalker. State funding for a six-year programme of work on the opera house interiors was announced in 2001, and the first fruits of the partners' collaboration will be revealed next week, with the opening of the redesigned reception hall and its foyer. The foyer will house a 14-metre long tapestry designed by Jørn Utzon, inspired by the Hamburg Symphonies of Carl Philip Emmanuel Bach, with a sequence of organic shapes - colour for the melody and black for the rhythm - expressing the music.

"The Sydney Opera House," Jan Utzon said last week, "has been the most expressive thing in our family." The understatement is telling, and typical. Jan's sister Lin, then 11 years old, took the telephone message in 1957 to say that her father - who was considered a rank outsider amongst 230 entrants - had won the opera house commission. "You have won this," Lin told her father, "and now you can give me a horse." Forty-seven years on, Lin, who has overseen the weaving of her father's tapestry in Melbourne, will be present at its unveiling in the new reception room foyer, the first tangible expression of her father's return to the building that has marked his life and the imaginations of architecture lovers all round the world.

Building work on the opera house started in 1959. In those days, communications between Europe and Australia were difficult: the flight in turboprop airliners was interminable and cost a year's salary, while long-distance calls from Denmark had to be booked a day in advance and routed through India. So that Mr Utzon could better oversee building work, the family moved to Sydney in 1962. The young Jan cut his teeth as a student architect by visiting the site office and climbing the growing skeleton of precast concrete shells. Today, with his father living in retirement in Majorca while acting as the senior partner in the restoration work, Jan flies to Sydney two or three times a year to visit the site and consult with Mr Johnson.

On his return to the city, Jan took numerous detailed photographs for his father, as a basis for developing their manual of guidelines. He was immediately impressed by how much people loved the building - the opera house is a place, he says, "where people have parties, where they congregate for happy times" - and by how much Sydney had reoriented itself. In the 1960s the city still faced towards the town hall. Now it faces the harbour and the opera house, and old dock buildings have been refurbished as offices and restaurants. It was originally envisaged that 19 people would work at the arts centre housed in the opera house. The current figure is 500 and they take pride in working there.

Examining the building itself, he was struck by the different colours the white sails - covered as they are in alternating courses of matt and gloss ceramic tiles - assume in differing light. (It is interesting that one of the guidelines his father has laid down for future generations is that the white sails should never be coloured.) Jan Utzon knows that the opera house is a building which defines its city and its country to the outside world, in the manner of the Empire State Building, the Eiffel Tower and the Taj Mahal.

"But that is not just because of the building," he says, "but because Australians have promoted it. They took it, with the koala and the kangaroo, and made it a symbol of the country. It was a building selected by Australians, who wanted something new, who wanted to give themselves a new profile. People say it is a brand for the country. It has certainly been made into a brand by commercial artists. The important thing is that it is seen to belong to Australians."

It is a far cry from the dark days of 1966, when Jørn Utzon was harried by newspaper campaigns questioning the cost of the building - some thought the money, raised by lottery, should have been spent on hospitals and schools - and the fact that it was designed by a Dane. At the same time, he found himself at odds with the new regime in New South Wales after the Liberal Party was returned to power for the first time in 23 years. The new committee wanted to alter some of the functions of the building, making the original opera hall, where the stage tower was already in place, into a concert hall. While the debate went on, the state government stopped payment to Mr Utzon and his 25 employees, eventually forcing him to resign.

The scandal was huge. Local architects, appalled at Mr Utzon's treatment, led marches to Sydney Town Hall; others reportedly gave up their profession altogether in protest.

It is not a period that Jan Utzon likes to dwell on, especially given his family's happy relationship with the city today, but he does say that the antagonistic press coverage at the time finally made it impossible for his father to stay on. Yet now the Utzons laugh if the saga is misrepresented in the media, as it was on Millennium Eve, when CNN announced that the Sydney Opera House had been designed by a "Dutch architect" who had "had to marry an Australian to get the commission".

To the Utzons, father and son, collaboration comes naturally. They have worked together for more than 30 years - their biggest joint project being the new national assembly building in Kuwait, completed in 1982 - and Jan has spent his whole life absorbing his father's ideas. "He does not need to say much," says Jan, "for me to understand." Jørn never pushed Jan and his brother Kim to become architects. Jan originally thought of being an aeronautical engineer, but was drawn back to architecture as a profession where he could have a wider effect. The tipping point came when he visited Frank Lloyd Wright's house at Taliesin West, Arizona. He knew then that he wanted to follow in his father's footsteps.

Jørn Utzon, too, is an admirer of Wright. He likes the use the American master made of space and light, and admires Le Corbusier and Mies van der Rohe for the same reason. But Jørn's greatest inspirations, Jan says, are nature itself, the way that things work together organically and vernacular architecture - whether it be Japanese, Muslim, Chinese or Mayan.

He got the idea for mounting the "sails" of his opera house on a raised platform from the memory of a visit to Mexico in 1949. After trekking through thick jungle, he climbed on to the raised base of a Mayan temple and was stunned by the commanding view it gave over the dense forest: the opera house, he felt, must command Sydney harbour in the same way.

He is also fascinated by the way that elements that make sense in themselves are combined in nature to make a richer whole. He likes buildings whose differing elements can be "read" like the page of a newspaper, with its headings, subheadings and stories. At the Sydney Opera House, the differing elements and their functions are beautifully clear: a solid, unbroken sandstone base, and, above it, the almost weightless sails - all roof and no wall.

The construction of the sails gave Jørn Utzon enormous problems. Nothing of their type or size had ever been attempted before. He developed with his engineers a system of precasting them in concrete sections, weighing three to seven tons each, which were then "sewn" together with cables, which were in turn anchored in the sandstone base. "I think it became such a remarkable building," Jørn Utzon said last year, "because we never gave in until we had found the best solution on everything."

The Utzons plainly have an easy relationship with Richard Johnson in Sydney, who in turn has great respect for the opera house's creator. The partners' development of a manual of principles also gave them a wish list of work to be done. It was a long one.

There were detailed aesthetic infringements: a shop had been built out on the concourse surrounding the opera house, and needed to be replaced; the main foyer was of no more than "ministry" standard and needed rethinking; the restaurant was filled with a confusing mass of conflicting shapes of desks, tables and chairs; the undercroft providing access to visitors was made dark and dirty by asphalt and car fumes and and could be brightened by being car-free and paved in light-coloured stone.

There were also more serious internal structural problems: the "reception room", originally conceived as a hall for chamber concerts, had a wonderful view but a miserable entrance and needed a new foyer and a more dramatic approach (the fruit of this work will be revealed next week); the basement theatres were served by a cluttered foyer with uneven ceiling surfaces. The solution to this will be unveiled next year once 1970s air-conditioning units have been removed and a new entrance and loggia opened out on to the west side of the opera house.

Most seriously, and most famously, the opera hall had bad acoustics, a cramped orchestra pit, which had been forced into what had originally been conceived as a hall for theatre, and a black ceiling, where Mr Utzon had planned "onion-ring" coloured banding, alternating white, red and gold, leading up to a darker area above the stage proper.

The schemes for improving the opera hall are still on the drawing board, with a view to executing them by the end of the decade. It may be decided to lower both the seating and the stage by up to four metres to improve acoustics, sightlines and access to the stage from the sides. Whatever the solution the Utzons and their partner come up with, the solution promises to be a crowning moment in finally giving the world's best-loved building the interior it deserves.

THE MAKING OF AN ARCHITECTURAL EPIC

The opera house averages around 3,000 events each year with audiences totalling up to two million.

There are nearly 1,000 rooms in the opera house, including the five main auditoriums.

There are 6,225sq m of glass. About 2,000 panes in 700 sizes were installed.

There are 645km of electrical cable. The power supply is equivalent to the needs of a town of 25,000 people.

The roofs are made up of 2,194 pre-cast concrete sections weighing up to 15 tons each. The roofsare covered with one million ceramic tiles.

The building covers about 4.5 acres. It is approximately 185m long and 120m wide at its widest point. The highest roof vault (above the concert hall) is 67m above sea level.

The entire building weighs 161,000 tons. It is supported on 580 concrete piers sunk up to 25m below sea level.