Pilkington has launched the world's first energy-saving window for buildings that can change colour on command.

The new electrochromic glass product changes colour from clear to a pleasing blue as it is adjusted to control the amount of heat and light entering a room. Called Pilkington EControl, the product ensures that the building occupants can enjoy the most comfortable conditions inside a buildings, while also saving energy. The darkening of the glass avoids overheating and reduces glare and reflection on computers screens. It means external shades are no longer required On the other hand, when there is little sunlight, the glass lightens and minimises the for artificial light. In winter, the coating on the glass ensures good heat insulation.

Pilkington EControl works by passing a low electrical voltage across microscopically thin coatings on the glass surface, activating a tungsten-bearing electrochromic layer which changes colour. The colour of individual windows can be controlled, or the total glazing in a building can be simultaneously altered by connecting it to the building's electrical management system. Trials in Germany have shown that Pilkington EControl can save up to half the energy required for air conditioning in a building.

The first installation of Pilkington EControl is in the Stadparkasse. a savings bank located in the historic downtown centre of Dresden, Germany.