Joined the Richard Rogers Partnership in 1985 and by 2007 the name of the practice changed to Rogers Stirk Harbour + Partners in recognition of Graham Stirk and Harbour's contribution to the firm, later renamed RSHP, after the death of Richard Rogers.
He has been the leading architect on two Stirling Prize winning entries for the practice in 2006 and 2009 for Terminal 4 of Madrid-Barajas Airport and Maggie's Centre, London respectively.
The Guardian's Charlotte Higgins described Harbour's work, in comparison with fellow partner Graham Stirk, to be "more expressive and sculptural" such as Madrid airport's brightly coloured Terminal 4.