The Inside Track

Interior glass market offers opportunity for contract glaziers willing to do their homework
Katy Devlin
January 4, 2016
Hartung Glass Industries teamed up with Joel Berman Glass for a massive 170,000-square-foot interior decorative glass project at Hamad International Airport in Doha, Qatar. The project, designed by HOK, called for glazing of the secure passenger corridors in three airport concourses. The glass was to be patterned in such a way as to obscure the view within the corridor up to eye level height. Joel Berman Glass developed the design for the glass—a series of algorithmically arranged designs using polygonal shapes. To achieve the desired obscurity, the design gradually transitions from opaque at the lower portion of each panel through translucency to full transparency at the top, according to a Hartung release. Hartung fabricated the 6,000 lites of glass for the project. About 75 percent of the glass is laminated, consisting of two lites of 8 millimeter low-iron tempered glass with a SentryGlas interlayer from Kuraray. The decorative design is printed on three surfaces of the glass. The remaining 25 percent of the glass is 3/4-inch monolithic parallelograms for stairwells, escalators and balustrades. Photo by Joel Berman Glass Studios.

From railings to walls, and office storefronts to elevators, glass is now an essential material for nonresidential interiors. “Everyone wants to see more glass in their building,” says Chris Hanstad, vice president of architectural sales for C.R. Laurence Co. “Anytime an architect can add glass railings, glass partitions or interior office storefront, it adds value to a building.”

Interior glass provides transparency, visibility and a modern design aesthetic. It’s a multipurpose material that offers nearly unlimited decorative potential alongside energy performance, security, sound control and other benefits. And it’s a market that continues to grow, offering opportunities for the entire glass industry, including the glazing contractor community.

“Advances in technology continue to expand the options for owners and ultimately the glazing contractors,” says Dan Stachel, vice president of SC Railing. “Those glaziers that are willing to expand their offering to more cutting edge technology will be the primary beneficiaries of the advancements being made.”

However, a large portion of interior glass work is currently going to other trades. “The drywallers, carpenters and furniture dealers are picking up a lot of this work that the glass guys could be getting,” Hanstad says. “There is money to be made in this market. You can get great margins—the glass guys can make money in this.” (See the article, “Make the Case for Division 10 Glass Projects” for more.)

Yet, entering the interior glass market successfully is not without its challenges. Owners have higher quality expectations for interior glass; jobsite logistics can be more complicated than on exterior glazing jobs; and code requirements can vary significantly across the country, sources say.

Glaziers that are willing to educate themselves about the nuances and requirements of the burgeoning market will be the ones to benefit most, says Brian Clifford, CRL technical director for architectural railings and metals. “We see a lot of companies that are OK at [interior glass projects]. But, there is a lot of opportunity for a company that is great at it,” Clifford says. “We do what we can to educate glazing companies. If they are successful, we are successful.”

Owned by Simon Property Group, simon. com, Del Amo Fashion Center in Torrance, California, is one of the largest shopping malls in the United States. Under the supervision of general contractor Whiting-Turner, the mall underwent a $200 million renovation that was completed in October. The project consisted of transforming the mall’s north end into a high-end retail destination.

Conceptualized by lead architectural firm 5+design, the newly remodeled north end incorporates GRS Taper-Loc Glass Railing from C.R. Laurence Co. The glass railing system was installed by ISEC and lines the entire interior perimeter to create a safer and more secure shopping experience for visitors. The railing features an on-trend allglass aesthetic and a custom bent base shoe designed to accommodate the curved glass used to produce flowing visuals, according to CRL officials.

High end, high expectations

In the interior glass market, companies must first understand the requirements and expectations associated with value-added products in an often high-end environment.

Interior applications frequently call for custom glazing or specialty glass products, which can require longer lead times, says Justin Burkhart, project manager, Key Glass LLC. “When dealing with custom products, lead times are longer. Specialty glass is not just a stock item that you can buy off the shelf,” he says.

Contract glaziers should plan ahead to accommodate the longer waits. Suppliers recommend that glaziers work with companies that offer additional service, as issues such as late deliveries, broken lites or other delays are more problematic and costly on highend interior projects.

“This is the service industry. When a store is opening, when tenants are moving in, those dates aren’t flexible. You can’t be missing a piece of glass,” says Louis Moreau, sales, AGNORA. “When you are choosing a supplier, consider these things. If you break a piece of glass, can you get a replacement in time? There will be a price for this, but going cheap won’t allow you to do that.”

Additionally, companies should prepare for demands for higher quality. A main distinction between exterior and interior glass projects are the expectations in terms of appearance. Interior glass is evaluated differently than exterior glass, and the quality metrics must be more rigorous, says Kevin Nash, marketing, AGNORA.

“We are accustomed to our products being evaluated from the sidewalk. However, when you place that same type of glass in a lobby, it will be evaluated by the owner from just a foot or two away. They will be close to the glass, they will be able to touch the glass, and they will be able to see flaws that might go unseen [on an exterior project],” Nash says.

An important appearance consideration for interior glass will be laminated edge quality, a growing concern, as exposed edges become more popular in applications such as railings, balustrades and partitions, sources say.

The all glass staircase and cantilevered landing at the Onassis Cultural Center in New York City represent what officials from AGNORA call a unique study in tension. AGNORA fabricated the glass for the staircase—the treads, railings and center supporting wall. The supporting wall is 4-ply, low-iron laminated glass with SentryGlas Plus structural interlayer from Kuraray. One end of each stair tread is supported by a ‘letterbox slot’ in the middle wall, while the other end is supported by a 2-ply ‘sawtooth’ stringer, laminated to the face of a second 2-ply lite, resulting in a 4-ply laminate center wall. The vertical stringers were made with 4-ply glass bonded together by Kuraray’s SentryGlas ionoplast interlayers, chosen for its rigidity and clear color. Walker Glass fabricated the nonslip glass for the stair treads. The architect for the project was Perkins Eastman,, and the contract glazier, Mistral Architectural Metal + Glass Inc. PPG Industries was the glass manufacturer.

“In general, people look more at the end of the glass than the face,” says Moreau. “They want extra clear glass, and they want the edge to be clean. [Fabricators] need to make sure the interlayer is well aligned, that it does not budge, so you can create that pristine quality on the glass.”

“Edge alignment is so important,” adds Burkhart. “With laminated lites, you have to make sure the edges are perfectly in line. You have to press your fabricators. But, it pays to get that perfect.”

Even more important than edge appearance is edge safety. Glass companies must ensure there are no sharp edges on the exposed end of the glass. “Quite often, you will have a complete balustrade where the top will be exposed. You don’t want people to cut themselves. You have to be careful how you finish the corners,” Moreau says.

Key to managing the higher expectations of interior glass projects is collaboration with the supplier. “Communicate early and often,” says Bruce Butler, general manager of Hartung Canada. “Find out what’s possible before bidding. A meeting with your supplier upfront can save a lot of time, money and headaches.”

Structural requirements

Beyond meeting appearance demands, contract glaziers must ensure an interior glass application meets code.

“Day in and day out, the biggest challenge we see for glazing contractors working in this segment is understanding the codes and glass limitations,” Hanstad says. “Many glass companies rely on the manufacturers to know these codes and rules. We want to provide a safe product, and will offer as much information as we are able. However, the local authorities having jurisdiction are different and have different requirements. We educate customers as we can and then point them to their local official.”

A centerpiece of the Mall at University Town Center in Sarasota, Florida, is a multi-story point-supported, glass elevator enclosure. Key Glass LLC was the glazing contractor for the project, and Innovative Structural Glass supplied the pointsupport fittings. The enclosure, called the Main Observation Elevator, features 2,600 square feet of 1/2-inch laminated, clear tempered glass around a steel structure.

In addition to the elevator enclosure, the project scope for Key Glass also included custom sunshades, a radius top curtain wall, main mall entrances with a total of 10,000 square feet of glass, two additional passenger elevators, glass balustrades in several locations, and a back-lit decorative glass interior partition supplied by Pulp Studio. The architect was JPRA Architects and Oldcastle BuildingEnvelope was the glass fabricator.

Many owners are looking to incorporate interior glass components into their spaces for the first time and aren’t aware of the limitations and the safety requirements. One common request that doesn’t meet code is oversized lites of monolithic glass, says Moreau. “People want to have gigantic pieces of very thin glass. We encounter this on an hourly basis. It’s simply not safe,” he says.

While manufacturers and suppliers can offer guidance about code requirements, glaziers need to educate themselves on the local code requirements so they provide a safe solution. Even if an installation gets past the building inspector, a glass installer could be liable if something goes wrong, sources say.

Hanstad also recommends that glaziers work with the manufacturers as they put together a complete glazing package. “We see customers purchasing miscellaneous parts and pieces for a project separately, and this can lead to problems,” he says. “For example, they might order a piece of tempered glass from their glass supplier and the hardware from us, and no one puts the puzzle together. Safety becomes a concern. The code becomes a concern.”

“A limited understanding of the structural requirements … is limiting the potential options for glaziers,” adds Stachel. Glaziers can “find a partner that can assist in the structural requirements of these systems. Changing codes and limitations on supply make having the right partner critical.”

Additionally, glass companies can also train and educate an employee to serve as an interior glass expert, Clifford recommends. “If they have an expert within their glazing company that knows railings, there is huge potential, as architects and general contractors are looking for qualified glazing contractors,” he says.

Jobsite logistics

Glazing contractors that have not worked extensively on the interior need to be aware of the additional handling and jobsite considerations before they bid, sources say. The logistics of simply getting a lite of glass to the installation site can be complicated, and if unanticipated, costly.

“Many of these projects require big glass, and installing big glass requires a different skill set,” Nash says. “The glass is heavy. You’re not going to be able to pick up the glass by hand with a bunch of guys. You need machinery.”

Installation companies should carefully look at the jobsite, measuring openings, elevator doors, etc., and create a plan for transporting the glass to the installation site. “If you’re doing interior, you have to know the feasibility,” Hanstad says. “Can you get the glass to the elevator? If you’re in a high-rise interior, there is always a concern about how you get the glass up there.”

Burkhart agrees. “Sometimes architects design something that calls for a 7-foot by 10-foot piece of glass. That can’t fit through the elevator,” he says. “You will have to plan ahead and think about how you can get all of that glass into the space before the exterior is completed.”

Installers should also get the proper equipment before taking on a major interior glass project, Moreau recommends. “Get the roll-on [lifters], get the crawlers, the spider cranes,” he says. “You can’t hand carry in these situations. If you don’t have the right equipment, you’re going to hurt your workers, you’re going to [cause] damage to the [jobsite], you’re going to break the glass. All of this can be avoided with the right equipment.”

Additionally, glass installers are often the last trade on the job for interior projects, presenting potential challenges due to delays at other stages of construction, or due to issues with the varying construction tolerances among the trades, Burkhart says. Collaboration with the general contractor and the other trades can help to ease these issues. “A lot of coordination from the GC’s end, that team involvement, can pay off,” he says.

To create a daylight-filled, open environment for its renovated offices in downtown Minneapolis, owners from Campbell Mithun looked to glass railings with minimal hardware. The owners and designers from Julie Snow Architects chose the ArchitectuRAIL Point Series and Base Shoe railing system from SC Railing.

The Point Series railing system is comprised of 2 1/2-inch stainless steel side mounted nodes, which eliminate the need for vertical balusters and allow for openness and clean sightlines. For Campbell Mithun’s multilevel staircases, SC Railing utilized 1/2-inch laminated tempered glass with a 0.60 SentryGlas Plus Interlayer from Kuraray, manufactured by Cardinal Glass Industries Inc., and installed by J & J Glass and Glazing. A custom wooden handrail completes the modern look. The balconies surrounding the stairs are enclosed with SC Railing’s Base Shoe railing system, which includes a 1/2-inch glass shoe anchored to the structural slab.

Advancements in technology are beginning to ease the pressures of some logistical challenges for interior glass projects, particularly in the planning, design and fabrication stages, Moreau says. A project team can now take 3-D measurements of the space to develop precise 3-D models. This allows a project team to discover problems at the design stage. Additionally, it assures more accuracy with measurement and fabrication, thus easing installation.

“We use a laser scanner and a laser tracker to produce a 3-D map of any space,” Moreau describes. “We can measure with accuracy. We can produce drawings from this information. If we have a staircase with holes, we are able to locate each pin to ±A/cb inch. This is the way to go in the future.”

Looking ahead

The growth trend for interior glass is expected to continue, sources say. “We continue to see great growth yearover- year with interior glass,” Hanstad says. “Owners and architects continue to look for new glass products and systems that offer frameless designs, transparency and optimal sound control. They want something that will give them unobstructed views and doesn’t create barriers or walls.”

They are also driven by safety, Butler says. “All overhead glass railings will soon need to be laminated. Smoke baffles aren’t going to win any design prizes; however, they are a public safety product that is mandated by building codes and can range from clear to creative,” he says.

Glass companies that are not currently involved in the interior glass segment should prepare to capitalize on this growth market.

“As the offering to the market broadens, I believe those glaziers willing to take risks will benefit,” Stachel says. “They'll need to develop partnerships with their customers and suppliers, as taking risks in construction is rarely encouraged.”

Katy Devlin is editor for Glass Magazine. E-mail Katy at