The guiding principle at Stansted has been to ensure that movement through the building is straight, unimpeded and on one level. The design of the terminal addresses this problem by banishing all services, baggage handling and rail links to an undercroft, leaving the concourse as a clear logical zone through which passengers proceed towards departure lounges and thence to shuttle links with the satellite buildings. By turning the building upside down and putting all the services normally housed on the roof, under the concourse, the roof is then able to admit and reflect light. Unlike the roof of Renault at Swindon, which was punctuated by columns and tie rods, the tubular steel structural 'trees' at Stansted support, but do not penetrate, the continuous roof canopy. Natural light floods in through the glazed side walls and through apertures in the roof.
Artificial light is bounced off the reflective underside of the domed roof shells.
The form of the terminal has been kept little higher than the mature trees on the site, yet it retains a strong and recognisable presence by night as well as by day. Stansted broke new ground in air terminal design. Long before its opening by the Queen in March 1991, the gull-wing profile had been widely publicised, and imitated. Not only was the Stansted terminal cheaper per square metre than any previous British air terminal building and its running costs fifty per cent less than any other terminal but it was also the first terminal to take the environment into consideration. By digging the bulk of the building into the site the impact on the surrounding landscape was kept to a minimum.