The Sydney Opera House was designed by Danish Architect Jørn Utzon, after his design won a competition in 1957. This highly controversial project at the time came to define Australia. The Sydney Opera House is a modern expressionist design, with a series of large precast concrete "shells", each composed of sections of a sphere, forming the roofs of the structure, set on a monumental podium. The building covers 1.8 hectares (4.4 acres) of land and is 183 m (600 ft) long and 120 m (394 ft) wide at its widest point. It is supported on 588 concrete piers sunk as much as 25 m (82 ft) below sea level.
The Sydney Opera House opened the way for the immensely complex geometries of some modern architecture. The design was one of the first examples of the use of computer-aided design to design complex shapes.
Although the roof structures of the Sydney Opera House are commonly referred to as "shells", they are in fact not shells in a strictly structural sense, but are instead precast concrete panels supported by precast concrete ribs. The shells are covered in a subtle chevron pattern with 1,056,006 glossy white- and matte-cream-coloured [[6256|Swedish-made tiles]] from Höganäs AB, a factory that generally produced stoneware tiles for the paper-mill industry.
Apart from the tile of the shells and the glass curtain walls of the foyer spaces, the buildings exterior is largely clad with aggregate panels composed of pink granite quarried at Tarana. Significant interior surface treatments also include off-form concrete, Australian white birch plywood supplied from Wauchope in northern New South Wales, and brush box glulam.
The project was built in three stages. Stage I (1959–1963) consisted of building the upper podium. Stage II (1963–1967) saw the construction of the outer shells. Stage III (1967–1973) consisted of the interior design and construction.
The government had pushed for work to begin early, fearing that funding, or public opinion, might turn against them. However, Utzon had still not completed the final designs. Major structural issues still remained unresolved. The forced early start led to significant later problems, not least of which was the fact that the podium columns were not strong enough to support the roof structure, and had to be re-built.
The shells of the competition entry were originally of undefined geometry. But, early in the design process, the "shells" were perceived as a series of parabolas supported by precast concrete ribs. However, the engineers were unable to find an acceptable solution to constructing them. The formwork for using in-situ concrete would have been prohibitively expensive, but, because there was no repetition in any of the roof forms, the construction of precast concrete for each individual section would possibly have been even more expensive.
From 1957 to 1963, the design team went through at least twelve iterations of the form of the shells trying to find an economically acceptable form (including schemes with parabolas, circular ribs and ellipsoids) before a workable solution was completed. The design work on the shells involved one of the earliest uses of computers in structural analysis, in order to understand the complex forces to which the shells would be subjected. In mid-1961, the design team found a solution to the problem: the shells all being created as sections from a sphere.
The interiors started with Utzon moving his entire office to Sydney in February 1963. However, there was a change of government in 1965, and the new Robert Askin government declared the project under the jurisdiction of the Ministry of Public Works. This ultimately led to Utzon's resignation in 1966.
The cost of the project so far, even in October 1966, was still only $22.9 million, less than a quarter of the final $102 million cost. However, the projected costs for the design were at this stage much more significant.
The second stage of construction was progressing toward completion when Utzon resigned. His position was principally taken over by Peter Hall, who became largely responsible for the interior design. Other persons appointed that same year to replace Utzon were E. H. Farmer as government architect, D. S. Littlemore and Lionel Todd.
Following Utzon's resignation, the acoustic advisor, Lothar Cremer, confirmed to the Sydney Opera House Executive Committee (SOHEC) that Utzon's original acoustic design only allowed for 2000 seats in the main hall and further stated that increasing the number of seats to 3000 as specified in the brief would be disastrous for the acoustics.
There was distinct controversy around this project. In mid 1965 a new Liberal government was elected in the State of NSW. The Minster of Works began questioning Utzon's designs, schedules and cost estimates and eventually stopped payments to Utzon. This accompanied by continual arguments, reached crisis point and Jorn Utzon resigned from the project, he left the country at the end of April 1966 with his family, never to return to see his masterpiece again. Following Utzon’s letter of resignation there were protests and marches through the streets of Sydney, demanding Utzon be reinstated as architect. The building was eventually completed by others in 1973.