An Inside Job

Interior Glazing Provides Increased Transparency and Creativity

By Jordan Scott

Glass isn’t a material used only on the exterior of a building. Glass can be seen throughout the interior of many modern buildings, offering increased transparency and cleanliness while simultaneously providing another medium for expression.

Several interior glazing trends have emerged, giving lobby walls, stairs and fire-rated floors a decorative flair.

Glass Stairs

Scottish Rite for Children Orthopedic and Sports Medicine Center—Frisco, Texas

The lobby staircase at the Scottish Rite for Children Orthopedic and Sports Medicine Center is colorful and winding. The translucent glass stairs provide pops of color that brighten the space.

Feature Walters developed a 12 metric ton steel structure for an unsupported, 720-degree spiral stair. The project team reached out to Standard Bent Glass (SBG), based in Butler, Pa., with whom it had worked previously. SBG provided the glass for the curved handrail and the individual stairs.

The railing includes 36 bent, tempered and laminated lites in the form of 20-inch tall parallelograms. Bobby Chestnut, sales manager of SBG’s decorative division, said the curved glass was challenging to bend because at such a short height the glass tries to twist in the tempering oven.

For the 35 stairs and two landings, SBG fabricated glass in nine different colors using SentryGlas Expressions PVB interlayers from Kuraray and low-iron Starphire glass from Vitro Architectural Glass. Chestnut says that color matching was a bit of a challenge because the team was given Pantone colors to match.

“Matching a Pantone color is always tricky with glass because it’s translucent versus Pantone color on paper,” says Shawn Hickman, SBG decorative division production manager, who adds that the company has stock samples to help expedite the process.

The stairs include anti-slip treads created using Dip-Tech ink. Hickman says the chemical composition of the ink reacts to water, gaining more traction as water is applied to it.

“It’s unlike anti-slip or slip-resistant float glass,” he says. “When water is applied it performs better.”

The project team required that no partial dots appear on the stairs; however, each of the stairs was pattern cut and did not have 90-degree corners. Not only did that make the pattern cuts and alignments more challenging but, according to Hickman, the SBG team had to ensure that the dot pattern aligned perfectly on the stairs.

HKS Architects was the architect for the project, which was completed in October 2018.

Glass Walls

3 World Trade Center—New York

The lobby of 3 World Trade Center is designed to let in natural light. The lobby’s walls are clad in floor-to-ceiling, 9/16-inch laminated glass made up of two ¼-inch lites. The glass wall panels were fabricated by McGrory Glass using a 0.067 Sefar Vision AL260/50 metal mesh interlayer to reflect light entering the building.

A light etch was applied on surface #1, giving a diffuse reflective appearance. A system of drop-in anchor hooks was developed to support the glazing and account for concrete tolerances underneath the glass cladding. A similar approach was used for the red accent walls, with RAL 3020 glass from Bendheim.

McGrory Glass fabricated more than 400 panels, totaling 14,500 square feet. They were double stacked with the bottom panel measuring 10 feet tall and the top panel 9.5 feet tall.

The lobby also includes metal finishes fabricated by G&H Arch Metals and installed by contractor Permasteelisa North America, which also installed the exterior curtainwall and interior glass wall panels. Stainless steel cladding is used for columns, railings, trims, cladding and structural support systems.

“The construction of the lobby glass walls on this project was especially challenging,” says John Vargas, senior tendering leader for Permasteelisa Interiors. “The architect was going for a clean, minimal look, which required precise tolerances and carefully controlled joint locations. On top of that, we had very little room to work out the concealed attachments to concrete walls. But our designers came up with custom details to control the continuous glass joint lines and minimize installation time, while maintaining a frameless look and minimizing deflection.”

Rogers Stirk Harbor + Partners was the architecture firm for the project.

Fire-Rated Glass Floors

Fayette County Courthouse—Lexington, Ky.

Fire-rated glass floors are giving architects the opportunity to brighten the lower levels of a space while still meeting code requirements. That was the case at the 120-year-old Fayette County Courthouse, which underwent a $32 million renovation last year.

Part of that renovation included the addition of two fire-rated flooring systems on the second and third levels. Directly above these systems is the glass dome, which brings lighting into the courthouse from the top of the building.

Technical Glass Products (TGP), based in Snoqualmie, Wash., provided its Fireframes ClearFloor System with Pilkington Pyrostop fire-rated glass, allowing the dome to be seen throughout the mixed-use building. The architecture firm, K Norman Berry Architects, in conjunction with Deborah Berke Partners, wanted to preserve the building’s character while updating it for its new purpose. They chose a glass floor rather than an opaque floor to showcase the historic dome.

The floor is a tempered, laminated walking surface with a steel framing grid. It’s fire-rated for two hours and can support loads up to 150 psf. The modular system includes several individual glass panels measuring approximately 48 by 50 inches. The fire-rated floor includes a ceramic frit on top, which creates a sparkly appearance to enhance the building’s lighting. It also functions as a durable, non-slip walking surface.

David Vermeulen, North American sales director with TGP, says there hasn’t been a major increase in the specification of fire-rated glass flooring systems overall, but that architects are becoming more aware of their availability.

“It really has to fit the space and the requirements of the building,” he says. “Anytime the architects or designers want to borrow light from other spaces, they can create this penetration through the floor.”

Jordan Scott is the editor of Architects’ Guide to Glass & Metal. She can be reached at

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