Glass at the cutting edge - Glass used in building design

Architectural Review, The, August, 2001 by Susan Dawson

On a much smaller scale, Foster and Partners, working with Techniker, have investigated the combination of glass - providing in-plane stiffness - with flat steel mullions, in a small glass conservatory on the roof of a building in Belgrave Square. The solid roof, carried on laminated glass beams, appears to float on glass eaves and the space is opened out by sliding doors which draw away from unsupported corners.

The future

It may be that the pursuit of transparency has reached its own glass ceiling. Concerns to conserve natural energy and reduce the greenhouse effect in the earth's atmosphere have led to designs which combine seamless transparent skins with high performance environmental control. The walls of the Business Intelligence Centre at Duisburg, by Foster and Partners, are a double-glass skin which modifies light and heat transmission, and delivers natural ventilation.

New responsive glass facades use self-regulating thermal protection and solar control measures to adapt in a dynamic way to changing light and weather conditions. In this way they meet the needs of building users while reducing energy consumption levels. [3]

The facade of the future must demonstrate that it contributes to sustainable symbiosis. Environmental control will be provided at a molecular level, using sophisticated responsive coatings. Glass inert and transparent, is the ideal substrate for such coatings. Already a new responsive panel, Serraglaze, can be used with glass to reduce the need for artificial light. It enhances daylight penetration, redirecting light from the sky by optical refraction and reflection.

A self-cleaning glass, originally developed for aircraft windscreens, is now available for use in external windows, produced by Pilkington. The glass, coated with microscopic chemical coatings, has properties which repel moisture and dirt, allowing them to be washed away during normal rainy weather.

Michael Wigginton, [4] who chairs a 10-nation European research agenda to develop the interactive facade, believes the eventual outcome will be nanometric, chromogenic energy control, in which energy flow will be controlled by a switch or an automatic sensor. Michael Davis has provided a poetic image of this future. 'Look up at a spectrum-washed envelope whose surface is a map of its instantaneous performance, stealing energy from the air with an iridescent shrug, rippling its photogrids as a cloud across the sun; a wall which, as the night chill falls, fluffs up its feathers and turning white on its north face and blue on the south, closes its eyes but not without remembering to pump a little glow down to the night porter, clear a view patch for the lovers on the south side of level 22 and to turn 12 per cent silver just before dawn.

(1.) Structural Use of Glass in Buildings, The Institute of Structural Engineers "" 10 Dec. 1999.

(2.) Working Details "" Susan Dawson, Emap Construct, 1999.

(3.) Intelligent Glass Facades, Andrea Campagno, Buxuauser, Basel, 1995.

(4.) Glass in Architecture, Michael Wigginton, London, 1996.