Warm edge - H.B. Fuller | Kömmerling: A canyon running through a facade

05/06/2025 | Print view

A modern glass building with a dramatic, wavy cut through its center against a clear blue sky. - © H.B. Fuller | Kömmerling; Millet Glass Industry — © H.B. Fuller | Kömmerling; Millet Glass Industry

In the One River North building in Denver, an artificial canyon winds its way through the 16-story structural glazing facade – a spectacular architectural detail and a complex function for the facade glass. These were implemented using the Ködispace 4SG warm edge system, which ensures energy efficiency in accordance with IGU units under the extreme climatic conditions of the city.

Over 3,460 insulating glass units were manufactured for the unusual 8,200 m² facade construction.

The three-dimensional planning model of the facade was translated into a complex construction task involving over 700 individual panels. These were shaped using a grid of CNC-bent galvanized rods, which were encased in metal mesh and textured plaster.

Each insulating glass element has a flexible, heavy-duty edge seal that combines spacers, desiccant, and primary sealing in a butyl-based sealant. The black color of Ködispace 4SG reflects the surrounding frame color, making the edge seal virtually invisible.

The Ködispace 4SG warm edge system from H.B. Fuller | Kömmerling thus ensures lasting energy efficiency and reliable gas tightness in the structural glazing facade, even at extreme temperatures ranging from –20 °C to +40 °C.

How is it assembled?

The facade glass was applied fully automatically by robots to guarantee reproducible precision of the reactive thermoplastic spacer system: The warm edge system consists of just one component that combines spacers, desiccant, and primary seal. Ködispace 4SG chemically bonds with both the glass surface and the secondary silicone seal.

This causes the entire edge seal to “melt” into a flexible yet highly resilient unit. It is specially designed to withstand heavy loads over the long term, ensuring that the insulating glass elements remain gas-tight for many years.

The thermal shocks caused by extreme changes in temperature throughout the day and seasons have no effect on Ködispace 4SG, as the developers emphasize. It remains flexible, does not tear, and loses neither its adhesion nor its gas tightness, according to the manufacturer. This ensures that the edge seal retains the noble gas filling in the space between the panes over the long term, maintains the insulating performance, and ensures a consistent indoor climate without frequent maintenance cycles.

With this technical core, One River North has not only made an architectural statement, but also created a facade that meets the high performance requirements of a demanding climate.

A canyon in the facade

An artificial “canyon” breaks through the glass facade, opening up the front of the building and accommodating green terraces. The three-dimensional planning model was translated into a complex construction task involving more than 700 individual panels. These were shaped using a grid of CNC-bent galvanized rods, which were encased in metal mesh and textured plaster.