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The ASHRAE proposal to reduce the window-to-wall ratio was dropped at the start of the year, but as a recent Urban Green Council report reminds us, the battle over glass performance is far from over. As part of the council’s efforts to establish better building envelope standards, the report calls into question the long-term benefits of expansive glass structures. Referred to as “high cholesterol buildings,” it explains how such buildings are on the fad diet of today, but have the potential to cause environmental problems in the future:

“We watch what we eat, exercise regularly, keep an eye on cholesterol, and make other common-sense lifestyle decisions now for better health in the future. But sometimes we take shortcuts, like fad diets that shed pounds in the short term while spiking our cholesterol and damaging our health in the long run. Buildings are no different…we seek shortcuts: ‘fad diets’ that make it seem at first glance that we’re building green, when in fact we are setting ourselves up to pollute more in the future.”

According to the report, one glaring, short-sighted fad diet in the building industry is using glass for the majority of the building envelope: “More glass translates into higher revenue today, but that same glass saddles buildings with poorer envelopes tomorrow.”

Undeniably, some glass still has a ways to go when it comes to energy efficiency. But, it also provides occupants with views to the outside world and access to sunlight. Since both are critical to occupant comfort and wellbeing, it is doubtful expansive glass building envelopes will be a passing fad.

Nicholas Holt, an architect at Skidmore, Owings & Merrill LLP, and an Urban Green board member, agrees. “Glass is not going anywhere,” says Holt in a Wall Street Journal article covering the Urban Green Council’s report. He adds that glass buildings will likely remain predominant for years because of the positive impact views and light have on human health and enjoyment.

As such, it is imperative the glass industry continues asking the right questions to ensure glass provides long-terms solutions that benefit both human health and the environment. How can glass become a better insulator, acoustic barrier or dynamic building element? What can we do to ensure framing materials improve thermal performance? What can we learn by partnering with architects to evaluate building envelope performance post-construction?

As the Urban Green Council report aptly points out, glass walls can last 50 years, and in some instances many more. By comparison, HVAC systems and other building equipment are typically upgraded and replaced every 10 to 20 years. This should underscore for all of us the importance of ensuring high-performance glazing contributes to energy-savings and promotes occupant comfort over a building envelope’s tenure.

The good news is there are many solutions we can pursue now. And, as the Urban Green Council sums up, “…with better glass, designed views, improved construction training, and greener codes, we can have buildings that are as healthy as they are beautiful.” Let’s do our part to make sure that glazing is part of the solution, and that future improvements are as healthy for building occupants as they are for the environment.

Jeff Razwick is the president of Technical Glass Products (TGP), a supplier of fire-rated glass and framing systems, and other specialty architectural glazing. He writes frequently about the design and specification of glazing for institutional and commercial buildings, and (past) chairs the Glass Association of North America’s (GANA) Fire-Rated Glazing Council (FRGC). Contact him at 800/426-0279.

Twenty-five years ago, one of the primary focuses in the fire-rated glazing industry was developing products with greater design flexibility. Architects were no longer satisfied simply using wired fire-rated glass in individual windows, borrowed lites and small view panes in doors. They wanted large, visually compatible glazed areas that could extend from floor-to-ceiling, wall-to-wall, and across multiple stories.

Over the last two decades, the push towards clearer fire-rated glass and sleek, fire-rated frames ultimately led to one of our industry’s greatest breakthroughs – fire-rated glazing systems. Designed and tested to work together as a cohesive unit, integrated fire-rated glass and frames made it possible for building teams to use fire-rated glass floors, roofs, and curtain walls to meet stringent fire and life safety codes.

Despite these advances, some building teams still question whether they can meet their design goals with fire-rated glazing. As is true in every industry, some manufacturing processes yield better results than others. But, the bottom line is there is no reason fire-rated glazing should force a major compromise on design goals. Here are several practical ways glass industry professionals can demonstrate how fire-rated glazing systems can advance building design.

Show how fire-rated glazing systems can do more with less - During informational sessions with design professionals, be sure to highlight fire-rated glazing systems with dual or triple functionality. Products that make it possible to accomplish more with less – like fire-rated glass floor systems and curtain walls – can help customers maintain their design intent and satisfy various project performance requirements.

Promote visual consistency with other building elements - Fire-rated glazing previously tended to have much thicker frames and glass to provide the necessary fire protection. This often created aesthetic discrepancies with nearby curtain walls, windows, and doors. Since many of today’s fire-rated glazing systems have crisp frame edges and clear fire-rated glazing, it’s important to show building teams that smooth integration with surrounding applications is possible. New options like silicone-glazed (SG) fire-rated curtain walls can even match the smooth, frame-free exterior surface of structural silicone glazed curtain wall systems.

Demonstrate design flexibility - For many architects, potential trade-offs between fire and life safety requirements and appearance are hard to swallow. If you are involved with the customer early on in the design process, the good news is in many instances there are readily available system solutions. One example is using fire protective materials with sprinkler systems. Approved systems like FireLite Plus WS in combination with TYCO Model WS Window Sprinklers can serve as an alternative to fire-rated assemblies requiring a 2-hour rating, when acceptable to the local Authority Having Jurisdiction (AHJ). Because the glass in the system provides fire- and impact-safety, achieves up to a 120 minute fire rating and can withstand thermal shock, building teams have greater design freedom than was possible with tempered glass alternatives. For example, the assembly eliminates the need for a 36 inch ponywall often previously used with the TYCO WS system, and allows the fire-rated glazing to be butt glazed for a seamless aesthetic.

Keep looking forward -Twenty-five years ago it was hard to see past the limitations of wired fire-rated glass. Now the industry is producing advanced systems like fire-rated glass floors and fire-rated curtain walls with the appearance of structural silicone glazing. Imagine where the glazing industry could be in another twenty-five years if we keep working to resolve fire-rated glazing design challenges. How are you working to change fire-rated glazing design perspectives in our industry?

Jeff Razwick is the president of Technical Glass Products (TGP), a supplier of fire-rated glass and framing systems, and other specialty architectural glazing. He writes frequently about the design and specification of glazing for institutional and commercial buildings, and is a past chair of the Glass Association of North America’s (GANA) Fire-Rated Glazing Council (FRGC). www.fireglass.com, 800/426-0279.

The opinions expressed here are those of the individual author and do not necessarily reflect those of the National Glass Association, Glass Magazine editors, or other glassblog contributors.

Last summer we invited a group of architects to Technical Glass Products to discuss strategies for improving building envelope performance. One of the questions on the table was how to optimize curtain walls and façades to address peak loads and total energy usage. While solutions ranged from hyper-insulated glazing that could be operated by users, to improved energy modeling, the success of these strategies kept coming back to how the building is used. 

Too often, high-performance glazing applications miss the mark because performance and use don’t align. This directly impacts people’s perception of glass. If a building has an expansive, double-glazed curtain wall with exceptional solar control and insulating capabilities, but all people remember is the heat and glare that enters through a different window near their desk, then glass loses credibility. 

So, how can the industry develop better glazing solutions that don’t favor performance outcomes over people? An important starting point is to engage the building owner and design team on how the building will be used.  

The more complete your understanding of how a building owner or architect envisions occupants using a building, the better your ability to tailor glass and framing products to meet multiple needs like occupant comfort, task and performance goals such as energy efficiency and life safety. Providing key decision makers with glazing solutions that provide widespread, functional value can also help products from being value-engineered out of the project later. Ultimately, this helps ensure the right product is used for the job.

Honest talk in the planning stage can also help the building owner and architect set realistic expectations. How often will people be near the perimeter of the building? How will user control for operable windows or shades get communicated to building occupants? Is reducing the glazing area necessary to improve energy efficiency? Glaziers and suppliers that identify and work through these questions are better equipped to make product or design adjustments that get the system closer to design and performance goals. 

As Whitney Austin Gray, research and innovation director for international architecture firm, Cannon Design, said in a recent Glass Magazine article, “energy versus health should not be a tradeoff.”

By getting involved early, the glass industry can work to ensure future buildings will have large windows and curtain walls, be filled with warm, natural light and support energy efficiency goals and occupant wellbeing.  

Jeff Razwick is the president of Technical Glass Products (TGP), a supplier of fire-rated glass and framing systems, and other specialty architectural glazing. He writes frequently about the design and specification of glazing for institutional and commercial buildings, and (past) chairs the Glass Association of North America’s (GANA) Fire-Rated Glazing Council (FRGC). Contact him at 800/426-0279.

The opinions expressed here are those of the individual author and do not necessarily reflect those of the National Glass Association, Glass Magazine editors, or other glassblog contributors.

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