My initial guess was double-pane, like the fancier kind of windows that insulate well. It's not clear if they really mean just double-pane glass or a true double skin glass facade, as described below?

http://www.glassonweb.com/publications/doubleskin/
In recent years, the use of double-skin façades, sometimes referred to as a "building in a building", has gained a lot of popularity throughout the world, due to characteristics such as durability, ecology, easy circulation of fresh-air, use of natural resources, etc. As indicated by the term "double-skin" such a façade is intended to mean a system in which two "skins" - two layers of glass - are separated by a significant amount of air space, that is to say, a second glass façade is placed in front of the first. This systems enables air to circulate between the cavity of the two façades, providing excellent air circulation. The type of double-skin façade then determines the type of air circulation. Of course, the most interesting systems are those designed in such a way that in addition to permitting natural air circulation, they also use solar energy, converting it into electrical energy.



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Note added at 16 mins (2003-12-05 12:37:20 GMT)
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http://gaia.lbl.gov/hpbf/techno_c.htm
\"Double-skin façades and natural ventilation\"
The double-skin façade is a European Union (EU) architectural phenomenon driven by the aesthetic desire for an all-glass façade and the practical desire to have natural ventilation for improved indoor air quality without the acoustic and security constraints of naturally-ventilated single-skin façades. ...