Maybe it's because of biases like these, but we tend to vastly underestimate the timespans in which cities can be radically remade. 50 years? Commercial build

Maybe it's because of biases like these, but we tend to vastly underestimate the timespans in which cities can be radically remade. 50 years? Commercial buildings being built in 1964 would have been expected to last 50+ years. Much of Chicago's lakefront is buildings from the turn of the 20th century or earlier. A skyscraper taller than 47 floors has never been demolished peacefully [1] 1 http://www.bbc.co.uk/news/magazine-20535821 http://www.bbc.co.uk/news/magazine-20535821