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.
Grand Opera House (Seattle)
Construction began March 24, 1923 on a parking garage described at the time as "the first of its kind in the Northwest" with "[p]atented ramps".
At that time it was described as $30,000 "five-story and basement" project with a capacity of 300 cars; a day before it opened on August 20, it was described as a seven-story building (6 floors and a basement) with a capacity of 350 cars, and having cost twice the original estimate. It was further described as having "heavy mill-type construction" with concrete floors, using the patented d'Humy Motoramp. The garage also included a full-service auto servicing shop. The resulting Cherry Street Garage became the third garage in the portfolio of the Griggs Garage Company, making it the largest such company in Seattle at that time.