Hardening School Exteriors

Constructing or retrofitting with security glass for school safety
Julie Schimmelpenningh
November 19, 2013

After the tragic events at Sandy Hook Elementary in Newtown, Conn., last December, much thought has been given to providing a more secure school environment. While natural disasters are a more likely threat to schools, schools should be prepared for the potential threat of intruder attacks. Targeted violence in schools is unpredictable, yet quite possible (since 1992, there have been more than 387 shootings in U.S. schools, according to StopTheShootings.org). Risk management efforts should focus on reducing risk and vulnerabilities through surveillance, detection, hardening of the structure and effective response capabilities.

Securing the building exterior is the only layer of defense that many schools are able to implement, and the glass industry plays a key role in this area. Constructing or, in most cases, retrofitting exterior points of entry such as glass doors and windows with security glazing is an excellent option for schools, both in affordability and practicality.

When remodeling an educational facility or building a new school, security should be a major player in the design process. Windows and doors are the easiest point of entry into a school, but they don’t have to be. Installing laminated security glass for all windows and doors makes forced entry much more difficult.

The exterior face of a building is vulnerable because of its accessibility and must be fortified against potential threats. For schools looking to structure an in-depth defense that creates cumulative security obstacles to slow down ingress, security glass offers a viable option. Multiple interlayers of laminated glass create a cumulative security obstacle to slow down intruder ingress and allow reaction time. Additionally, laminated glass offers protection, while still allowing daylight to filter in, and the school is able to maintain an aesthetically pleasing architectural look.

One obstacle in the effort to increase school safety is building age. The United States has an aging school building stock, and old schools are not capable of keeping up with today’s potential security threats. Most glazing in schools is based on safety glazing codes instituted in 1966 and federally mandated in 1977. ANSI Z97.1/CPSC 16 CFR 1201 calls for protection against cutting and piercing injuries from broken or falling glass. And requirements in the International Building Code and International Residential Code pertain to overhead and sloped glass and/or deal with hurricane and seismic requirements. This type of safety glazing is not sufficient protection anymore.

Safety Glazing Guidelines

To help guide architects and school boards through the process of specifying safety glazing for schools, Eastman established some guidelines. First, designers and schools should make a realistic assessment of what is needed, what is affordable, and what can be immediately implemented. The focus should be zoned protection, such as hardening doors and windows—the easiest point of entry—with security glass.

Eastman recommends installing laminated glass to make forced entry more difficult. This will deter ingress and reduce “break-and-reach” capability. Unlike annealed or tempered glass, laminated glass stands up to multiple assaults from a blunt or sharp object. It would take several blows before an intruder could break through the security glass, allowing valuable time for anyone inside the school to call the police, sound an alarm, lockdown classrooms, or move students to a safe area.

Today’s schools have an increasing amount of glass windows and doors because of the positive benefits it brings. For extra security, laminated glass is an easy, cost-effective measure in protecting against forced entry and bullet resistance. Compared with traditional annealed or tempered glass, laminated glass can secure the building more effectively.

Laminated glass offers the same clear visual benefits as ordinary glass, an important feature for security. From the inside, glass allows occupants to see someone approaching the school. From the outside, glass can help responders locate the intruder or victims.

Upon impact, laminated glass will shatter, but glass shards remain held together by the bonded interlayer, minimizing risks associated with flying or falling glass. Laminated glass is available in a variety of thicknesses—the thicker the interlayers, the more resistant to impact.

Eastman advocates the voluntary adoption for security glazing standards and hopes that these recommendations will become building standard. The following specific codes would help harden a school’s exterior:

  • Security Against Ballistic Attack ASTM F1233 / UL 752

Entry doors are the most vulnerable exterior feature and have been easily compromised in past school shootings. A better option that would slow down an intruder from entering the school is hurricane-rated, high-impact (large missile) glass, or even ballistic glass. High-performance safety glass would significantly slow down an intruder’s break-and-reach through ability, allowing personnel inside the school to react to an emergency. This glass specification could require existing doors to be replaced completely as the framing system for such heavy configurations is specialized, but the added security and safety factor is worth the additional expense.

  • Security Against Forced Entry/Exit ASTM E2395

First floor windows allow easy access into a school. This risk can be minimalized by equipping all lower level glass with basic laminated glass, which typically requires a 0.03-inch-thick interlayer. This will deter ingress, retain glass, and slow break and reach. Laminated glass can be retrofitted into most existing window and door systems, and can contribute to compliance for security windows per ASTM E2395 - Security Performance of Window and Door Assemblies with and without Glazing Impact.

Architects and school districts should also be aware of legislative efforts to safeguard school buildings. Among the current legislative proposals is U.S. Federal Legislation H.R. 2352, which would allow appropriations for funding security equipment. These building safety upgrades include locks, cameras, panic alarm systems, intercom systems, metal detectors, and hardening structural improvements such as installation of high-performance security glass. H.R. 2352 has been approved by the House Judiciary Committee, but the House of Representatives has not announced whether it will consider the measure.

Another key piece of legislation that could have an impact on school safety is Florida Bill HB 201/SB 1088. The intent of the bill is to increase school building safety by securing points of entry via doors that can be locked with a key from inside without impeding the ability to exit without unlocking the door; using bullet-resistant locks and latch mechanisms in doors; securing or positioning door windows to prevent intruders from breaking through and opening doors; and instituting bullet-resistant (or in the case of Florida, hurricane-resistant) window standards. Unfortunately, Florida Bill HB 201/SB 1088 died in May at the K-12 Committee, but there is always hope that all or some of it could be revived and reconsidered for all states in the United States.

Whether mandated or voluntary to do so, architects and school boards are stepping up to make existing schools a safer place for students and staff. Hardening entry doors and lower level windows with high performance security glass is an affordable, effective solution. For additional information on specifying glazing systems for schools, visit www.keepsafe.com.

The author is Global Applications Manager, Advanced Interlayers for Eastman Chemical Co., www.eastman.com. Schimmelpenningh is a participating member of numerous industry organizations, and can be reached at jcschi@eastman.com.