Fire-rated assemblies must also meet the following code requirements:

• Occupancy Separation (Table 508.4)
• Building Elements (Table 601)
• Fire Separation Distance (Table 602)
• Fire Barrier Assemblies (Table 707.3.9)
• Fire Barriers – Section 707
• Fire Partitions – Section 708
• Smoke Barriers – Section 709
• Smoke Partitions – Section 710
• Fire Door and Fire Shutters (Table 715.4)

Understanding IBC Label requirements for fire-rated glazing is also valuable for the design team. Fire-protection-rated glazing is mandated to bear a label or other identification, permanently placed onto the glazing, showing the name of the manufacturer, the test standard, and information required in IBC Section 716.3. that shall be issued by an approved agency. These markings can include the following designations:

• W: Meets wall assembly criteria. (ASTM E 119 or UL 263)
• OH: Meets fire window assembly criteria including the hose stream test. (NFPA 252 or UL 9)
• D: Meets fire door assembly criteria. (NFPA 252 or UL 10B or UL 10C)
• H: Meets fire door assembly “Hose Stream” Test. (NFPA 252 or UL 10B or UL 10C)
• T: Meets 450°F temperature rise criteria for 30 minutes. (NFPA 252 or UL 10B or UL 10C)
• XXX: The time in minutes of the fire resistance or fire protection rating of the glazing assembly.

CONSTRUCTION TRENDS AND THEIR IMPACTS ON FIRE-RATED GLAZING

The global construction glass market is anticipated to grow at a 7% compound annual growth rate (CAGR) between 2021 and 2031 to reach a valuation of over $90 billion by 2031. The market surpassed $46 billion in 2020, with a 5% CAGR between 2016 and 2020.¹ “The need for building construction glass is being driven by urbanization and demand from residential and commercial sectors. The increasing demand for lighter, stronger, and more energy-efficient construction glasses will continue to drive construction glasses production,” stated a Fact.MR survey on sales of construction glass.²

“Offering new modes of visual pleasure and spatial experience, glass has benefited from major advances in engineering and structural innovations,” noted Daniel Fox, AIA New York.³ Glass offers unique advantages over other construction materials. It transmits natural daylight and is unaffected by typical weather. The color of glass does not shift or morph due to changes in the environment, allowing it to maintain the original design aesthetic envisioned for a much longer time. Glass is also highly recyclable; it can be shaped and reused numerous times. Its raw materials are sand, soda ash, and limestone, as well as recycled glass, making it sustainably sourced. This recyclability and availability has allowed glass to emerge as a cost-effective alternative over other building materials. Glass is 100% recyclable and can be endlessly recycled with no loss of quality, according to the Waste and Resources Action Programme.⁴

Aesthetic Trends

Not only is glass on the rise as a percentage of building materials, but there is also increasing customer demand for larger expanses of glass in buildings. Expansive windows, often featuring sleek aluminum frames, have become a defining feature in both contemporary homes and commercial spaces. This shift towards maximizing natural light and unobstructed views transforms a space’s aesthetics and enhances its functionality and energy efficiency. Across the industry, manufacturers report demand for larger glass profiles and an increased focus on energy efficiency. Demand for more glass and bigger glass exposures is a dominant trend that is not going anywhere. Leading manufacturers report an exponential increase in orders for scenic doors and larger expanses of glass, with door panel sizes increasing 10% since 2017.

Glazing that enhances a project’s energy efficiency, daylighting, and natural ventilation is a client priority. As occupants spend more time confined indoors, design preferences are shifting toward larger expanses of glass in windows and doors that preserve exterior views to foster connection with the natural environment. Large windows complement various interior design styles, from modern and minimalist to traditional and rustic. They serve as focal points, allowing a showcase of exterior surroundings or landscape.

Architects are increasingly turning to advanced glazing solutions to obtain all-round performance and to meet the challenges associated with achieving a green building certification rating for their project.⁵ Advances in coatings and properties can be combined to offer architects a wide array of options that accomplish a range of jobs. Increasing daylighting through windows substantially reduces the electric lighting load and can minimize heating and cooling loads. In fact, improving the lighting system design and incorporating daylighting often provides the greatest opportunities to reduce building energy costs.⁶ Daylighting and exterior views also improve occupant health. Innovative glazing can today attain very high levels of energy performance, reduce the embodied and operational carbon totals for a site, and accomplish impressive safety ratings, including fire resistance.

Application Scenario: New Secondary School Project Requests Increased Glazing in Fire-Rated Stair Corridor
The design team of a new secondary school has been tasked with increasing daylighting and visible light transmittance in a fire-rated stair corridor through glazing. The school board hopes to allow natural light to enter the building while reducing or eliminating solar radiation and solar heat gain, to enable daylighting without compromising occupant safety, to make the stair assembly more open and appealing with glass, and to provide a connection to the outdoors to increase productivity and improve the emotional health of students. The final goal is to achieve a fully glazed stair enclosure that meets code without compromising design aesthetics.

This request reflects a growing design preference for clearer, larger sizes of fire-rated glass. However, if the design team plans to expand the glazing area in the stair corridor, then a minimum 1-hour fire-resistive glazing should be used to meet code requirements. The IBC requires different ratings for protected openings in a 1-hour exit corridor depending on the glazing application.

In the end, a new glazing technology is selected to secure the school’s goals. A single chamber foaming interlayer fire-resistive glazing technology, which uses two panes of glass and a single chamber, demonstrates fire-resistive performance at 120 minutes. The maximum exposed area for 120-minute products gives the designers 44.9 square feet. This exceeds the industry average of 30 square feet for the exposed area of higher-rated products. The new technology also provides a Visible Light Transmittance as high as 90%, versus the industry average of 82% VLT for multi-chamber products. Ultimately, the designers create a 2-hour stairwell. Ninety-minute Fire-Resistive Glass is used to exceed 100 square inches in the door vision panels while 120-minute Fire-Resistive Glass in Resistive Framing is used for the sidelites and transoms.

Allowing more daylight to enter and reach deeper into facilities, as well as offering larger views uninterrupted by framing, is consistent with biophilic design principles, which can improve the mental and physical health of the buildings’ occupants.

Labor Trends

A shortage of skilled craft labor in the North American construction industry has been an unfortunate trend for more than two decades. As far back as 1999, research called attention to the lack of skilled labor in the construction industry.⁷ The problem has only increased in the years since.⁸ In 2017, the Associated General Contractors of America called for improved recruiting and compensation, noting that chronic labor shortages could have significant economic impacts.⁹ The construction industry averaged more than 390,000 job openings per month in 2022, the highest level on record, and the industry unemployment rate of 4.6% in 2022 was the second lowest on record, higher than only the 4.5% unemployment rate observed in 2019.¹⁰

Photo courtesy of Vetrotech Saint-Gobain North America

Skilled labor shortages and the need to look after the well-being of installers are influencing innovation in fire-rated glass.