Planning fallacy
The Sydney Opera House was expected to be completed in 1963. A scaled-down version opened in 1973, a decade later. The original cost was estimated at $7 million, but its delayed completion led to a cost of $102 million.
Sydney Opera House
An international design competition was launched by Cahill on 13 September 1955 and received 233 entries, representing architects from 32 countries. The criteria specified a large hall seating 3,000 and a small hall for 1,200 people, each to be designed for different uses, including full-scale operas, orchestral and choral concerts, mass meetings, lectures, ballet performances, and other presentations.