Yes, glass was installed and monitored at various locations round the world. These were chosen to test the glass under a variety of weather conditions. The glass was tested for six months in the Arizona desert, six months in Florida, twelve months in Ohio in the USA, twelve months in Gelsenkirchen in Germany and thirty months outside our Technology Centre in the north west of England.

The longest real life test was in the north west of England and lasted thirty months. During that time, measurements of how dirty the glass looked were taken every two weeks. During the thirty months, there was only one occasion when the Pilkington Activ™ looked dirtier than the normal glass.

As self-cleaning glass is such a new product, there is not yet a quality standard to measure it against. NSG Group is working with other glass manufacturers, Standards Institutes and Universities to formulate recommendations for such a standard. At present, Pilkington Activ™ is tested against EN1096 Part 2, but this concerns the durability of the coating, not how good it is at self-cleaning.