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.
Museum of Sydney
The original house, which was Australia's first Government House, was built in 1788 and later abandoned. The foundations were exposed by archaeologists in 1983. The new museum building on the site was designed by Denton Corker Marshall architects. The museum was built as part of the Governor Phillip Tower development and is managed by the Historic Houses Trust of New South Wales.