Glass continues to dominate the world of architectural design in the United States, even as external forces such as energy concerns, violent storms, man-made threats and glass breakage must be continually considered. The beauty of glass, with its abilities to let in light and visually connect indoor with outdoor spaces, ensures that glass will always play a significant role in design.
Enhancements to glass, including the use of high-performance interlayers and coatings ensure that this favored material continues to have a bright, sunlit future. But as the global economy slows, the future of architectural glass lies in the concept of multi-functionality, or glass that can achieve a number of design objectives in one product.
New York City can be seen as an epicenter of glass trends in the United States, where both the positive aspects of glass are, at times, in conflict with the realities of external threats. Tougher energy codes, hurricanes, glass fall-out from high-rises, terrorist threats and even bird safety have amplified the need to find creative ways to continue to use glass in buildings. New York often sets the trends for the rest of the country, where similar issues are being addressed.
“The requirements for building facades and glazed openings from large cities to rural housing have evolved. Glass, through the incorporation of multifunctional characteristics, has changed as well, and those needs can be met by using laminated glass”
“The requirements for building facades and glazed openings from large cities to rural housing have evolved. Glass, through the incorporation of multifunctional characteristics, has changed as well, and those needs can be met by using laminated glass”
New York is embracing change on many levels, underscoring the need for high performing architectural products that can deliver on multiple levels. The 2020 New York City Energy Conservation Code (NYCECC) went into effect
May 12, 2020, affecting all new buildings and alterations and requiring new thresholds for energy conservation.* The New York City Department of Buildings recommended tougher building codes to prevent risk from falling glass in 2019, after several incidents in New York and other large cities raised concerns.**
The City has also implemented new measures to protect birds from flying into glass. The measures would require newly constructed or altered buildings to use glass and special treatments to help birds distinguish between glass and clear airspace or fly-throughs. Strategies include solar shading elements, reduced reflectivity, and coatings integrated with interlayers. Following 9-11, stricter New York City building guidelines have helped produce some of the safest buildings in the world, including the glass-sheathed One World Trade Center (Freedom Tower) that replaced the Twin Towers. High performance interlayers were used to add safety and security to one of the most visited buildings in the world.
The Trend: Multi-functional Glass
When considering how to enhance the performance of glass, few architectural products pack as much power as the simple laminated glass interlayer. Polyvinyl butyral (PVB) interlayer in laminated glass offers a slate of added benefits to glazing, which include safety, security, storm protection, acoustic performance and structural stability. In past decades, advanced interlayer products from companies like Eastman Chemical Company have furthered the science of interlayers moving from conventional to specialty products.
Many of these advanced interlayers can also be combined into one laminated glass unit or incorporated as one or more lites of an insulating glass unit to provide strength, impact resistance for hurricane and security applications such as schools and high-risk facilities.
The hygienic aspects of glass and ease and efficiency of cleaning versus more porous façade and wall coverings have also added to the multi-functional intrigue of using glass. The surface of glass has been found easy to clean with germicide and disinfecting solutions with virtually no impact on the durability of the glazing when following manufacturers’ recommended practices.
Chicago’s Windy City Benefits from Multi-functional Glass
The 150 North Riverside, in Chicago’s famed riverfront, provides insight into how laminated glass technology can be multi-functional. The pencil-shaped building (point down!) seems to defy both gravity and the city’s winds with its nearly invisible eight-story lobby. Noted Chicago architects Goettsch Partners were called upon to design an office tower that would fit in a prime Chicago riverfront parcel of land so narrow that no one had bothered to consider it for decades. By law, any building was required to be set back from the river for pedestrian access. Chicago’s trains also run through the parcel, further complicating an already perplexing problem. The architect’s response was a unique core-supported structure with a seemingly impossible small footprint at the base of the building.
To respect the building’s unusual form, which dramatically cantilevers above the lobby, expansive, ultra clear, non-reflective glass was used to enclose the entire space. There were multiple challenges: the structural span for the glass was 85 feet and required large format glass. A clear invisible appearance with minimal joints, hardware and color shifts was needed, as well as a seamless transition between the lobby wall and the plane of the curtain wall above.
Structural strength was also a major consideration. For the back wall of the lobby, the architects selected Saflex® Structural interlayer. It is designed specifically for applications where increased interlayer rigidity and high glass adhesion are required, as was the case at Riverside. Saflex Structural was able to handle the intense loads on the building while also offering other essential safeguards, including UV screening that protects the lobby’s magnificent art collection, edge stability, clarity and noise abatement. One product was capable of functioning in multiple ways.
Hollywood Sees Starlight with Multifunctional Glass Applications
Scheduled to open in December of 2020, the new Academy Museum of Motion Pictures offers insight into multi-functional glass. The most dramatic part of the brand-new museum—The Sphere—has a glass, rooftop dome, requiring the excellent structural capacity found in Saflex Structural interlayers. In a town where glamour and glitz are practically a requirement, the giant glass sphere sparkles appropriately. The museum gives visitors a behind-the-scenes look into how films are made while celebrating the power of the movies. Hollywood superstars Steven Spielberg and Tom Hanks helped spearhead the project. And its designer, “starchitect” Renzo Piano, is as well known as many of the actors celebrated inside the museum.
German engineers Knippers Helbig Advanced Engineering designed a unique “shingle” system to accommodate the complex geometry and high load requirements of the sphere. The glass rooftop dome consists of a single-layered, braced steel structure covered in shingled glass panels—two panes per grid. These were manufactured with Saflex Structural
interlayers and installed by Permasteelisa North America. Only the inner pane of the shingled glass system is supported by an invisible, custom dead load pin connection, leaving the outer glass pane supported by the interlayer, making a stiff interlayer essential. Due to Saflex Structural’s structural strength, resistance to creep at high temperatures, and rigidity, the engineers found the interlayer met both requirements.
Another important multi-functional attribute relates to aesthetics, which are highly valued in Los Angeles! Since the glass edges are exposed to varying weather conditions, the interlayer helps protect against delamination, preserving the sphere’s beautiful appearance. Low-iron glass without a coating created the final effect. Acoustic and safety benefits are also achieved by the use of one interlayer system.
With the collaboration of some of the best architectural and engineering minds from both Europe and America, the motion picture industry will be celebrated for years to come. And for those in the glass industry, the sparkling glass dome will also remain a star.
Packed with Performance
While trends come and go, the “trend” of multi-functional glass has long-lasting, impactful staying power. High-performance interlayers and/or the use of special coatings add to the stability, design flexibility and adaptability of architectural glass. Where once there were limitations due to changing energy guidelines or building safety codes, multifunctional laminated glass with PVB interlayer, in conventional or specialty form, has adapted to market needs. Meeting building codes, providing strength, sound damping, solar control, visual beauty and impact resistance for safety, security and post breakage performance are all functions attainable in a single glass unit with proper design. The requirements for building facades and glazed openings from large cities to rural housing have evolved. Glass, through the incorporation of multi-functional characteristics, has changed as well, and those needs can be met by using laminated glass.
This article was originally published in IGS Magazines Summer 2020 USA Special Edition: Read the full Magazine here for more thought-leadership from those spearheading the industry
Author: Julia Schimmelpenningh
Architectural Industry Technical Manager for the Advanced Material Interlayers business of Eastman Chemical Company. 30+ years’ experience in lamination and laminated glass applications support. She provides technical product support to glass fabricators, Architects, Designers, Engineers and Specifiers.
Her work includes new product development, qualification and commercialization of laminated glazing solutions, regulatory development and industry education and association support. Julia also manages the America’s Customer Applications and Support Laboratory in Springfield, Massachusetts.
Julia is a very active and solid contributor in the glazing industry being a member of ANSI, ASTM, CGSB, ISO, GICC, NGA and other organizations. Most recently receiving the highest award given by ASTM International for her contributions to the industry and being designation an Honorary Fellow and the prestigious C.G.Carney Award from the National Glass Association.