Why Structurally Glazed Building Elements are So Impressive

Anthony Callas, VP Business Development, Structural Glazing Systems, PFEIFER Structures

There are two types of designs: one that plays it safe and relies on techniques utilized for decades, while the other challenges the boundaries of possibility. You may have observed some impressive structural glass facades that made the building stand out. What made it so memorable? Was it the crystal-like ultra-clear edges of low-iron glass?Or, the minimalist, discrete glass attachments which were absent the bulkiness of aluminum mullions? Could it have been the elegance of highly crafted architecturally exposed structural steel, the narrow strands of a tensioned cable net, or even the almost invisible structural glass fin? It could have been any of the above. Each memorable structure is an example of excellence in design, engineering, and construction. Such excellence can only be achieved by those who dare to explore beyond the templates of their predecessors.

The once state-of-the-art systems of glazed pockets and pressure bars of curtain wall and silicone butt joint or VHB glazing tape adhesion to mullions and components had passed the crown of engineering’s achievement to a new system and style of glass facades. As engineering science progressed, insight into material properties and advancement of computational design methods created new forms of glass attachment. The resulting product is ingenious facades of engineered glass never before seen.

When considering a glass building, the first thought for many is the regimented geometry of curtain walls or window walls that are potentially pre-built as unitized rectangular panels. 

Ingrained in the modern era are the glass boxed towers, which became a standard in high-rise design and construction. They reached incredible heights and gave cities their identifiable skylines. The glass industry owes much to this period.

However, there is a new trend in glazing, started by projects with large expansive openings that wrapped around a corner. The opening itself was infilled with tinted monolithic glass and a corner a quirk mitered joint and clear silicone sealant. What’s most impressive was its surrounding structure of cantilevered flush-framed rough-sawn beams supported by a distant post allowing for as much of an unobstructed view as possible at a corner of the building. That image of architectural ingenuity combining strength and openness planted a seed that was to alter glazing forever.

Exciting structural glazing projects like the BNK Busan Bank in South Korea, the Berlin Hauptbahnhof in Berlin, and the glazed canopy at the Q6Q7 Mall in Mannheim, Germany,have utilized this new technique of structural glazing. The BNK Bank is an excellent example of a cable net-supported curtain wall with large glazed lites and a narrow sightline. The impressive Berlin Hauptbahnh of building envelope is designed with modern cable and glass fin supported glazing. A combination of full locked cables, open spiral strand cables, glass fins, and specialty hardware supports the massive terminal’s curtain wall and canopies. The canopies at the Q6Q7 shopping mall provide both diffuse light and sun protection with a translucent white interlayer for strength and beauty. 

This new wave of structurally glazed building elements is inspiring clients and designers to create phenomenally unique buildings. So, how do you factor into the most exciting trend in glass? If you’re a developer, owner, architect, engineer, or contractor, how would you go about including these extraordinary structurally glazed systems into your project? The favored solution for this is to incorporate a highly capably specialty steel-and-glass preconstruction team along with the project architectural, engineering, and construction team. 

This preconstruction team would provide design-assist insight, preliminary engineering, specifications, and various kinds of estimates from rough-order-of-magnitude to guaranteed-max-notto-exceed pricing with each design iteration. The specialty team would work closely with the project team to safeguard design aesthetic, thermal properties, acoustic transmission control, and all engineering requirements. From architecturally exposed structural steel to steel tensioned cables or rods; to glass fins or simple support or cantilevered extension with point supports or clamp held, the structural glazing system would exceed the expectations of designers, builders, owners, and occupants.

"Structural glazing is an attainable excellence in architectural building elements that can distinguish a building from its peers and last for decades"

Furthermore, it is critical that a capable, consistent, and comprehensive specialty steel-and-glass team has the right chemistry with the project team to enhance the entire design, engineering, and construction process. There are always unique problems that a complex project will face. However, when a team of designers, engineers, builders, and specialty consultants can achieve harmony in resolving conflicting needs, it shows that the participants come from a mutual disposition of professionalism, passion, dedication, authenticity, and relentless desire to create something special.

Structural glazing is a pinnacle of contemporary design and engineering. It lets in light while offering thermal insulation and acoustic attenuation while protecting from wind, rain, snow, and seismic events. Structural glazing is an attainable excellence in architectural building elements that can distinguish a building from its peers and last for decades.