Behnisch Double-Wall Facade

It is this south-facing wall that is the most technologically innovative.

Offices here are enclosed with a double-skin glass curtain wall, framed by extruded-aluminum mullions, that provides a high degree of acoustic, solar, and thermal control.

The outer skin of monolithic glass is separated from the inner layer of insulating glass by an air space of 0.8 meters, containing retractable perforated aluminum sunshade louvers to reduce solar heat gain and redirect daylight into the building. The outer skin incorporates operable louvers at the top and bottom to ventilate the cavity, while the inner wall has operable windows to naturally ventilate the offices

.http://www.architectureweek.com/2010/0505/design_1-1.html