The Twenty-five Year Award is an architecture prize awarded by the American Institute of Architects (AIA) to buildings and structures that have "stood the test of time for 25 to 35 years", and that "[exemplify] design of enduring significance". The Twenty-five Year Award was first presented in 1969, and has been handed out every year from 1971 onward; the most recent winner, in 2015, was the Broadgate Exchange House, in London, England.