Deadly mass shootings have led to debates over mitigation and public safety, especially in schools. Parents, teachers, architects and school stake holders all have concerns about how best to keep schools safe. Security glazing is just one of the ways to delay entry and protect school occupants.
In a webinar titled, “Security Glazing for Schools,” part of Technical Glass Products’ Resilient Design Symposium hosted by Architectural Record, Urmilla Jokhu-Sowell, technical and advocacy director for the National Glass Association, spoke about the differences in security glazing types and gave an overview of standards impacting school design.
She explained that there were 23 new safety laws in 2018. That same year, Homeland Security published its Primer to Design Safe School Projects in Case of Terrorist Attacks and School Shootings.
Most schools are 40 to 50 years old, said Jokhu-Sowell, who cited statistics from the National Center for Educational Statistics in 2011, which show that 45% of schools were built between 1950 and 1969, while 28% were built before 1950. ANSI Z97.1 – Voluntary Safety Glazing Standard was not created until 1966 and the CPSC 16 CFR 1201 – Federal Mandate for Safety Glazing wasn’t adopted until 1977, meaning that many schools were not designed with safety glazing principles or codes.
Jokhu-Sowell also explained the difference between safety and security glazing. Safety glazing is the protection against accidental human impact or broken glass caused by natural causes of breakage such as storms. The standards are code-driven and required. Security glazing is the protection against forced entry, blasts or ballistics. These standards are voluntary.
According to FEMA guidelines, school security should be approached in different layers, with the first layer consisting of the property line or natural or manmade barriers; the second layer consisting of the perimeter of the school’s property to the school; and the third layer consisting of the building envelope itself.
Glass plays an important part in the building façade because it provides daylighting, which not only helps students concentrate better, but keeps classrooms well-lit, says Jokhu-Sowell. Natural light also doesn’t depend upon a power source. The FEMA guidelines recommend that architects consider using ballistic-resistant glazing in high-risk school areas, such as areas close to highways, and laminated glass instead of conventional glass. It also suggests placing windows away from doors so that if a window is broken the door cannot be unlocked from the outside, and using steel window frames securely fastened to the surrounding structure.
There are several security glazing configurations:
- Single safety tempered glass lite – safety and daylighting applications;
- Single tempered lite with film/plastic – forced-entry, blast, safety, fire-rated and daylighting applications;
- Laminated glass – enhanced forced-entry, enhanced blast, enhanced safety, containment when broken, impact, enhanced acoustical, fire-rated and daylighting applications;
- Laminated insulating glass units (IGU) – further enhanced forced entry, blast and safety, containment when broken, hurricane impact, enhance acoustical, energy efficiency and daylighting; and
- Multiple ply laminated glass – enhanced forced-entry, blast and safety, containment when broken, ballistics, hurricane/tornado, enhance acoustical, fire-rated and daylighting.
Laminated glass, laminated IGUs and multi-ply laminated glass all can delay entry by varying degrees. Film on glass does not provide bullet-resistance but can help keep the glass in the window provided that it’s anchored to the frame itself.
The industry has responded to the recent public response to threats by focusing on products for delaying entry, according to Jokhu-Sowell. These products, such as laminated glass, give first responders time to arrive and schools time to react and lock down.
Several standards have been published or are in the works to address these concerns. NFPA 3000 provides information about how schools can plan for, respond to and recover from these attacks.
ASTM’s New Standard on Mitigation of Armed Aggressors in Educational Institutions is being developed by ASTM International Committees F12.10 and E54.05 to “describe risk and threat analysis, design, specification, selection and application of building plans and systems to minimize the impact of armed aggressors in educational institutions.”
ICC’s Ad Hoc Committee on Building Safety and security is undertaking a comprehensive review of current code requirements as they relate to developing the necessary balance between facility security and safety considerations.