Rendering of the Elbphilharmonie
That's when Herzog & De Meuron's Elbphilharmonie, the new Hamburg concert hall, is expected to be done: in 2017. When construction started in 2007, the anticipated completion date was 2010. And if you think that is bad, the initial cost was estimated at 77 million Euros. That has blown up to around 790 million Euros. (Don't they have Microsoft Project in Germany?)
Update: There's mention in the article I link to of the "4,000 square meter building." Ahem. That is the size of a public plaza that is part of the building, not the square meterage of the building itself.