The built environment of any city inevitable exhibits path dependencies and maps imperfectly onto its current accommodation requirements. In turn this impacts on the city’s territorial competitiveness and its capacity to retain and attract the key sectors most likely to drive its economy. In an era of global competition the ability to reposition the urban built environment becomes an even more important concern for those tasked with retaining and enhancing urban competitive advantages. This paper explores these arguments through a case study of the repositioning of London’s built environment in the first two decades of the 21st Century. This repositioning has taken place in a largely uncoordinated way through a combination of area wide regeneration schemes, major infrastructure investments, a desire for tall buildings, the ability to attract global real estate capital flows and the hosting of a major global sporting event. The analysis attempts to rank the relative importance of these factors and examines the extent to which London provides a template for other cites attempting a similar repositioning of their built environment with the view to enhancing urban competitiveness.