Terminal 5 (T5) at London Heathrow, to a design by Richard Rogers, occupies a surface area of 300,000 sq m spread over four storeys. The whole project includes the terminal building itself, two smaller satellite buildings, a control tower, parking for 3800 vehicles, a six-platform train connection, 112 shops, a 600-room hotel and a new motorway junction. The project called for over 75,000 lighting units, devised by Thorn in close liaison with BAA (the airport management company) and a team of lighting experts. All luminaires are energy-saving and purpose-built; most use adjustable and inspectable Dali power-packs coupled to timers and light/movement sensors. The light can thus be regulated and even turned off when not required. The main brief from the management company was to balance functional lighting and architectural needs. The large terminal areas are lit by special ceiling-mounted triple-headed luminaires fitted with a metal iodide 35W projector and visors to illuminate the vault girders, a 250W metal iodide projector to light the passenger area below and a compact 42W fluorescent tube as emergency lighting. Where natural light is in short supply, as in the underground railway station, the main source is blue-light Titus luminaires (fitted with a 35W T5 bulb).