Built in 1988 in the La Défense business district, this 130 meter tall Tower saw in 2011 its lobby completely restructured, to allow natural daylight access, and to visually open the Tower towards the bridge structure that supports it. The architecture firm Hubert & Roy, that led the project, asked Concepto to step in and re-think with them the diurnal and nocturnal image of the lobby.

Largely open today, the lobby, crowned by a large glass roof supported with a 12-meter high metal net, is basked in daylight, which changes through time and in the space over days and seasons. At certain times of the year, according to the path of the sun, sunrays penetrate the lobby and project on the walls and floor the shadows of the net.

In order to animate these light projections, to sporadically color the volume of the lobby and to reveal the seasonal changes in the path of the sun, a glass pane system was integrated into the net, made of vertically suspended, colored dichroic glass panels, tinted glass panels and reflecting panels made of mirror polished stainless steel.

Thanks to this optical system, a true light trapping device, the lobby offers visitors and occupants, on a daily basis and year long, moving, ever-changing diurnal images that are a delight to discover.