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 Academy
Demand for a new building was met in 1864, when the new Education Act provided for the construction of a new school. The Sydney Board selected a site on Pitt Street, where the present telephone office now stands. This building was officially opened on May 1, 1866 and cost $3600. It was used until 1882, at which time larger accommodations for educational work were needed. The second Sydney Academy building was destroyed by fire in 1901.