A new level of double-skin glass façadeBerlin, Germany | January 18, 2023
Anyone passing through Washington Platz in Berlin can’t fail to notice ‘cube berlin’. An eleven storey, 19,000 square feet, perfect cube of a building, that features a unique double-skin glass façade.
The outer skin is multi-faceted and triangular in pattern, so reflections are redirected to change the building’s appearance depending on viewing angle, the weather, and the time of day. While also helping it merge into its surroundings and blur the edges of reality. At night the lighting inside the stepped thermal inner skin dominates, giving the outer a shimmering effect as it reflects a more subtle night-time ambience.
The aesthetic impact is clear, made possible by a carefully balanced combination of glass types. Less apparent is how this double skin ventilated façade is also a perfect example of how architectural glass design can deliver on the structural and energy requirements of today’s ‘intelligent’ commercial builds.
As well as its stunning architecture, cube berlin, a CA Immo project, is committed to environmental sustainability. It offers reduced energy consumption compared to traditional office buildings and the ventilated double-skin glass façade is a crucial factor in this.
Maximising natural daylight for the building’s occupants was also an important consideration. As Torben Østergaard states: “We were aiming at a fully glazed façade, not only to produce the best possible daylight conditions but also to allow for the particular feel of floor-to-ceiling windows that offer great outside views.”
In addition to coated glass products, the team at Guardian Glass provided technical expertise and commercial support throughout the design phase, drawing on many years of experience and knowledge.
‘’The biggest challenge was the need to combine the design and aesthetic concept of the architects and the technical requirements of the building. We had to identify exactly the right combination of products to use, and this involved a great many tests and calculations, as well as producing many different samples.‘’
Olivier Beier Costa
Guardian’s Architectural Sales Manager
As well as maximising the use of natural daylight, the glass façade not only offers high protection against solar heat gain but provides natural ventilation. To prevent overheating of the façade cavity, both solar-control coatings and solar-absorbing PVB layers have been integrated into the outer glass skin.
Matthias Schmidt, Head of Development at Investor CA Immo states: “We are aiming for DGNB Gold certification on this project. The design of the façade is actually very energy efficient, with a clever technical concept that includes, among other things, regaining energy from heat. An effective energy solution that will negate the common idea glass buildings are severe energy spenders.”
Another major challenge was the unique structural demands on the glass for this project. To solve these, a new structural interlayer compatible with the PVB interlayer needed to be introduced and this combination then approved nationally during the design and construction phase. This new innovation increases edge stability lowers the risk of delamination and reduces the Yellowness Index.
‘’In order to make the building work as a sculpture on the square, we were looking for reflective glass that emphasises the surface while also visually reflecting the surroundings. Our hope is that the design will prompt passers-by to ask ‘What’s actually going on here?’ and maybe even evoke a sense that the building is actually flirting a little bit with you.‘’
Architect, partner at 3XN
Investor/Project Developer: CA Immo Deutschland GmbH
Glass: Guardian Glass
Consultant in façade engineering, energy design and green building certification: DREES & SOMMER
Glass Processor – outside glazing: BGT Bischoff Glastechnik AG
Glass processor – inside glazing: Reflex
Photo Credits: ©3XN and Guardian Glass,LLC
● Guardian SunGuard® HD Diamond 66 Ultra and SuperNeutral SN 62/34 solar control glass
● Guardian ClimaGuard® Premium2 thermal insulating glass.
● Guardian UltraClear® low-iron float glass.