Foster and Partners' recent refurbishment of the British Library of Political and Economic Science for the London School of Economics includes a huge top-lit atrium, capped by a gigantic opening glazed unit.
The north-facing glazed dome, by Kawneer, allows daylight to be drawn into the heart of the building and avoids the problems of glare and solar gain.
Andrew Purvis, project architect, says that 'having calculated the path of the aggressive midsummer sun, we cut the dome off at the corresponding angle. A reflector at the front of the dome bounces the light back and down into the atrium.
Because it's pure north light, we don't have any of the problems associated with glare and solar gain and didn't need to use high-performance glass.'
The glazing, which features specially designed triangular structural silicone glazed top and bottom hung vents, is also an integral part of the library's natural ventilation strategy and its control of smoke in the event of a fire. All of the opening vents in the dome are controlled by actuators linked to a weather station on the roof.
'To create the stack effect at the top of the building, we needed something like 61m 2free area of ventilation, 'says Purvis. The vast majority is provided by individually controlled vents at the base of the dome; the balance by the triangular opening vents in the dome itself.