The Principal Tower, completed in mid-2019 on the edge of London’s trendy Shoreditch artists’ district, makes an impressive mark on the city’s skyline with its 162 meter-tall, elegant glass façade and its 50 stories.

Designed by Foster + Partners, the floors hang like transparent layers between the delicate, horizontal façade bands that mark the individual levels. Here, too, the extensive use of glass in the outer skin is vital to this filigree look. Given the structure’s dimensions, every detail of the highly energy-efficient curtainwall façade had to be planned—right down to the spacer bar. This invisible construction element plays an important role in the construction of generously glazed skyscrapers. It improves the insulation effect at the edge of the insulating glass panes and keeps them at a constant parallel distance from each other.

The persons responsible for planning therefore decided to use the warm edge spacer bar Swisspacer Ultimate to construct the façade glazing. Due to its special gas and vapor-tight foil, this spacer bar prevents the gas filling from leaking out of and water vapor from penetrating the space between the panes. The approximately 300 residential units in the Principal Tower are also optimally thermally insulated due to the warm edge spacer bar for double glazing units, according to the company. This delivers a significant reduction in energy costs and increases comfort levels in the rooms: Drafts caused by the sinking of cold air or the formation of condensation on the panes are thus effectively avoided.