Following the longest public inquiry ever undertaken in the UK, construction of the station was granted in November 2001 by transport minister Stephen Byers as part of the approval of the Heathrow Terminal 5 project. Funded by British Airport Authority (BAA), construction of the extension as part of the T5 construction took 6 years. As part of the construction, Heathrow Terminal 4 tube station was closed for 20 months between January 2005 and September 2006 to allow the connecting junctions to be constructed.