Opera House model rebuilt after 2,500 parts are found

An intricately detailed perspex model of the Sydney Opera House, which vanished more than 30 years ago, has surfaced in a warehouse and has gone on display - but only after being reassembled with considerable difficulty. The model, which was feared lost or destroyed after being sent to the 1974 Washington World Expo, was found inside 24 storage crates at a customs warehouse in western Sydney. It was, however, in 2,500 pieces, and the instructions for putting it back together were missing.

John Dare, the Opera House's asset development manager, told The Australian newspaper that he hunted fruitlessly through various archives and searched the basement of the Opera House itself. He even got in touch with the family of Harold Lambert, who was hired to build the model in 1966, but to no avail.

Eventually a local firm, Porter Models, was hired to reassemble the pieces, a project that took 2,000 hours to complete. Mr Lambert's daughter, Christine Pettinger, said the model was "very complex, like a giant jigsaw".

While the building took 17 years to complete, the model was seven years in the making. Ms Pettinger told the Sydney Morning Herald that her father had to invent a transparent glue, and make his own tools. He heated the perspex to mould it into the shape of the distinctive soaring roof shells.

The model, which was based on 8,000 detailed drawings, is 4.5m long by 3m wide by 1.8m high. It was designed to help contractors to solve the engineering challenges posed by the unusually shaped building, such as how to install ventilation and air conditioning systems. Built to a scale of 1:48, it replicates perfectly the interior of the Opera House, with its recital halls, foyers, staircases and terrace overlooking the waters of Sydney Harbour. It also includes miniature engineering plant rooms, and plumbing fixtures.

The model was unveiled publicly yesterday for the first time since 1974, at a trade fair at Sydney's Darling Harbour. It will go on display at the University of Sydney's architecture faculty later this week, before being given a permanent space at the Opera House.

Mr Lambert was given the commission after Joern Utzon, the visionary Dane who designed Australia's most famous landmark, was forced off the project. Mr Utzon left the country, vowing never to return, following a bitter dispute with the New South Wales government about spiralling costs.

Mr Utzon was sacked amid public disquiet at the expanding construction schedule and a budget blow-out from A$7m to A$100m. He left Australia seven years before his Modernist icon opened in 1973, in the shadow of Sydney Harbour Bridge. The saga of the epic falling-out between the architect and his political masters became the subject of an opera written by an Australian composer, Alan John, entitled Eighth Wonder, and first performed at the Opera House in 1995.

After Mr Utzon was ousted, his plans for the interior were scrapped to cut costs. The legacy was a structure whose inside spaces failed to match its aesthetic beauty; one critic called it "grand piano on the outside and rusty xylophone on the inside".

Those problems are being addressed as part of a A$24m (£9.7m) revamp of the building, which saw the Queen open a new colonnade in March. The facelift also provided an opportunity for the rift with Mr Utzon to be healed. He agreed to be the principal design consultant, although he is now too infirm to travel, and his son, Jan, is overseeing work on the ground.

While Mr Utzon left before his building was completed, Mr Lambert was forced to abandon his model partly unfinished after government funding was withdrawn. His daughter said that decision "broke Dad's heart". She said that the model "absolutely consumed his life... he lived it and he slept it".