With some fellow journalists, I was taken for a tour earlier this week of Heathrow airport’s Terminal 5, the biggest free-standing building in the UK, it may surprise you to know, and part of a long-overdue effort to transform the hellish ritual of air travel into something more civilised. The entire operational system has been designed with the passenger in mind, we were told. There are 96 check-in kiosks. The interior space is vast: five levels of 10 football pitches each, to use the vernacular form of measurement.

But this is large scale with a human face. The modish concerns of helping to preserve the environment are observed throughout. Eighty-five per cent of the rainwater that falls on the terminal’s elegantly arched roof will be recycled. There are hundreds of thousands of trees and shrubs. Everywhere you look, plump figures boggle the mind. There will be 12,000 bags per hour zipping around the 18km of conveyer belt in the bright sunshine that 30,000 sq metres of reinforced glass will allow to filter through. It’s amazing, you may think, what you can do with £4.3bn.