Fire-Rated Glazing Advances Code-Driven Designs in Refurbishments
From building industry professionals to facility managers, a longstanding complaint about spaces built to fire and life safety code standards is their inferior aesthetic.
Whether it’s a fire-rated corridor with light-restrictive concrete blocks or an exit door with tiny wired glass door lites, the design limitations associated with fire-rated materials are a source of frustration for professionals seeking to create inviting spaces for building occupants.
This frustration is even more pointed for design professionals tasked with refurbishing or retrofitting educational and healthcare facilities. Many existing structures rely on traditional fire-rated building materials, like concrete and gypsum, to provide fire protection. Their dense, opaque form restricts critical light transfer and visibility, leading to dark, poorly lit spaces that are challenging to reinvent within code constraints.
The good news is material advances now make it easier to overcome this hurdle. Manufacturers have developed clear, sleek and high-performing fire-rated glazing systems that design professionals can use to replace opaque fire-rated materials and better meet occupant wellbeing goals. This article will use the refurbishment of Chicago’s Grant Thornton Tower to illustrate these points, explaining how similar principles can be applied to educational and healthcare facilities.
The Fire & Life Safety Challenge
When Grant Thornton, LLP, moved its U.S. headquarters in 2015, “its lease was saddled with a very dark, almost unusable area on their most important floor,” said Ken Novak, NCIDQ, Associate, Stantec Architecture.
The second floor, which was designated as a gathering place, had no access to daylight. It was essentially a long, dark corridor. The firm desired to open up a gypsum covered, fire-resistive wall to allow ample light into the space, as well as provide visibility to the lobby below and out to the Thompson Center and City Hall across the street. As Novak explained, introducing daylight was “problematic due to the codes regarding separation of the lobby from the tenant space.” There are many types of fire-rated materials that can meet this life safety requirement, but relatively few that allow light transfer.
The architects had all but “given up on the idea of daylight flooding the space,” until they found their solution with fire-resistive-rated glass and frames.
A Better Way with Fire-rated Glazing
Fire-resistive glass provides nearly the same level of clarity as ordinary float glass, carries fire ratings up to 120 minutes, passes the fire and hose stream tests and offers up to Category II impact safety ratings. Most notably, it can serve as a barrier to heat, enabling it to pass the test standards for solid walls. When paired with fire-resistive frames, buildings teams can use such glass to create large expanses of see-through walls in areas that would otherwise require concrete, gypsum or other opaque fire-rated materials to meet code.
In the case of Grant Thornton, the project team replaced an 84-foot (25.6 m) long drywall partition with approximately 821 square feet (76.3 m2) of two-hour fire-resistive curtain wall frames and glass. By changing an opaque wall into a clear one, the result is a welcoming, light-filled space that is “very popular and one of the showstoppers in the building,” noted Novak.
While Stantec Architecture opted to use a fire-rated glass curtain wall to achieve their aesthetic, today’s design professionals have numerous options from which to select, including:
- door assemblies;
- transparent glass walls;
- curtain walls;
- silicone-glazed curtain walls; and
- glass floors.
Applying Fire-rated Glazing Design Principals
The Grant Thornton Tower refurbishment serves as a powerful illustration of how design professionals can use fire-rated glazing to turn code-driven areas into attractive, light-filled and functional spaces. By applying similar principles to educational and healthcare facilities, design professionals can use this multifunctional material to create light, bright and safe spaces conducive to occupant wellbeing.
A primary benefit of fire-rated glazing is the ability to better maximize light penetration. For instance, during a retrofit, building teams can orient fire-rated glass systems to draw light deep into a building’s core. They can place fire-rated glass systems directly in line with non-fire-rated glazing systems, use fire-rated glass panes or curtain walls in corridors or main gathering areas, or incorporate them in typically hard to illuminate spaces such as stairwells.
Design professionals can also use fire-rated glass floor systems to maximize light transfer. By aligning these new systems beneath skylights, natural light can pass down into rooms that otherwise would be cut off from sunlight. Similarly, large glass floors can serve as atriums or light portals for stairwells and belowground spaces. This was the case in Northwestern University’s Engineering Life Sciences Building infill, where Flad Architects used a two-hour, fire-resistive-rated glass floor system as a large central atrium. The system satisfies the atrium’s two-hour fire separation code requirement without restricting critical light transfer.
“We needed a fire barrier in the atrium, but we didn’t want researchers and students to be in the dark,” explained Matt Garrett, project architect at Flad Architects. “The fire-rated glass floor system allowed us to compartmentalize a very large volume of space without blocking off access to daylight.”
Another key way fire-rated glass systems can benefit healthcare and educational facility renovations is through enhanced visibility. Extended glazed areas promote visual connectivity between workspaces, encourage occupant interaction, improve wayfinding and ensure first responders can quickly see in and evaluate potential threats during a fire.
One example of using fire-rated glazing to enhance visibility is the expansion and renovation of the Niles North High School Aquatics Center in Skokie, Illinois. “We needed to provide a two-hour fire-rated separation between the existing building and the new addition, but we wanted the facility to read as a single aquatics center,” explained Michael Maloney, LEED AP BD+C, design director for Legat Architects. “A visual connection between pools was crucial for the concept, as well as for safety and security.” By installing fire-resistive-rated glass and frames, the firm was able to meet these multiple needs and maintain a visual connection between existing and new parts of the building.
Today, there are numerous ways design teams can use fire-rated glazing to promote visibility, including using full-lite fire-rated glass doors and expansive fire-rated glass curtain walls to draw the line of sight through nearby expanses of glazing.
Modern fire-rated glazing products also provide buildings professionals with enhanced design flexibility. Instead of using uninviting, opaque fire-rated materials or institutional-looking wired glass limited to 100 square inch panels, design professionals can select from a range of sophisticated fire-rated glass systems that allow them to achieve their desired aesthetic.
For example, fire-rated glass systems that utilize new generation fire-rated steel frames are sleek and slender. They make it possible for design teams to more closely match the look of non-rated frames. Silicone-glazed fire-rated curtain walls provide a smooth, frame-free exterior surface that visually ties in with neighboring structural silicone glazed curtain wall systems. And, one of the most recent options on the market, a butt-glazed fire-rated system, enables extensive fire-rated glazed walls with virtually uninterrupted views.
Building teams can also select from fire-rated frames in a wide array of custom colors and finishes to achieve nearly any look. Frames can be custom painted or powder coated to match nearly any color scheme. There are even authentic hardwood, fire-rated framing options, as well as products with the look of stainless steel.
For far too long, design professionals have been forced to temper their design goals for the sake of fire and life safety. Today, this compromise is no longer necessary. Design professionals can use fire-rated glass systems to turn unusable, out-of-date areas in healthcare and educational facilities into attractive, light-filled and safe spaces.
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). Visit www.fireglass.com or call 800.426.0279 to learn more.