The Beauty of Hardened Glass

Glass has long been a favorite material of architects and designers, and there are many good reasons why. Glass brings light, comfort, and openness to a space. Plus, it’s more durable and sustainable than most building products, and it’s 100% recyclable.

In K–12 schools, the sense of openness that glass provides helps promote happiness, creativity, and communication. Increased daylighting and visibility connect students to others, nature, and the experiential environment, which can improve learning, behavior, and test scores. Along with the benefits of glass in K–12 design, however, come greater concerns today about its security and safety—especially with the increase in active shootings on school campuses.

Surveys have found that most K–12 schools have not hardened the glass on exterior door vision panels and sidelites, particularly those used at key entrances—an intruder’s most likely first target. Unreinforced glass in those doors and windows can be the weakest link and easily breached, as the Covenant School in Nashville tragically experienced.

Security and Safety Films

Findings like this are why the Texas Education Agency (TEA) created its School Safety Standards Rule last November that states, “Windowed doors on the ground level or windows adjacent to or near a door and large enough for someone to enter if broken must be reinforced with entry-resistant film unless within a secured area.” This is the minimum requirement that Texas says all schools in the state must complete by November 2024.

In the latest edition of the PASS Safety and Security Guidelines for K–12 (page 58), the Tier 1 Architectural Component under the Building Perimeter Layer section specifies that, “Security window film at least 14 millimeters thick (350 microns) should be installed on all exterior door vision panels and sidelites. Security film serves to deter or delay the ability of an attacker to breach a doorway using a firearm or other tool/weapon, in addition to limiting injuries from glass shards resulting from a blast, fire, accident, natural disaster or severe weather event. This type of solution can be retrofitted within most commercial window systems and incorporated into insulating glass units.”

There are a number of renowned brands of industry-tested security film products on the market. When installed and anchored properly on the inside surface of glazing, they can be extremely effective in buying the extra precious minutes needed for law enforcement to respond and students, teachers, and staff to shelter in place. No safety and security film is bulletproof, but the higher the product’s tier level rating and tear resistance, the longer it holds together and more difficult and discouraging it is to breach a glazed entrance.

One-way, reflective film products installed on lower classroom windows also offer a layer of discouragement by preventing intruders from seeing in, while still allowing occupants to clearly see out. Turning off lights in the classroom and other shelter-in-place safety procedures can also reduce an assailant’s visibility. Graphics film treatments are another option that blocks the view from outside. They also create an opportunity for aesthetic branding and mottos that project school spirit in a positive way.

A Note on Wired Glass

For many years, wire-reinforced glass was the only fire-rated glazing and was commonly installed in educational settings. Unfortunately, many people often mistakenly considered it to be safety glass.  Designed to hold in place in case of fire, it couldn’t actually withstand much human impact at all. Tragically, too many individuals suffered razor-sharp wire lacerations, usually caused from breaking the glass unintentionally. Now safer, wire-free fire-rated glazing has replaced that older technology. Some newer wired glass products have emerged; however, jurisdiction code restrictions limit their use.

Whatever It Takes

For existing (non-wired) glass door and adjacent window applications, reinforcing with security film is an economical and highly effective retrofit upgrade. For higher tier protection, denial and ballistic solutions like School Guard Glass and Riot Glass may be necessary. These installations are more common in new construction where it’s more practical to integrate the appropriate metal door frames, hinges, and other hardware into design specifications to handle the extra weight and thickness of the glass.

PASS Guidelines don’t include product-specific recommendations, but they do define the related technology. Their Tier 3 Architectural Component under the Building Perimeter Layer section (page 59) describes Ballistic Security Glass for Exterior Door Vision Panels and Sidelites this way: “Several forms of security glass are available, incorporating acrylic, polycarbonate and other materials. Each has specific characteristics, weight and thickness depending on the intended use and level of ballistic resistance required. Security glass should be installed in all exterior door vision panels and sidelites that meets or exceeds the UL Level 3 standard for ballistic protection.”

Along with keeping potential assailants at bay, certain glass security/safety films and most ballistic solutions also offer an extra layer of protection against storm-related impact and other natural disasters, depending on their product ratings and compliance with AHJ codes.

It’s clear that today’s hardened glass solutions can be a powerful deterrent and safeguard when part of a comprehensive school safety and security action plan. It’s also clear that our schools absolutely need it to maintain the positive qualities glass brings to the learning experience—a livelier, more open environment that helps students stay creative, engaged, at ease, and happier.