26  |  SCHOOL PLANT MANAGER MAGAZINE  |  SUMMER 2026
T
o keep school buildings safe, 
facilities managers need to keep 
track of an ever-changing array 
of products, standards, and 
code requirements. Windows 
are no exception. Despite the proven 
benefits of daylight and views of the 
outdoors on student performance, glass 
creates vulnerable points in the building 
envelope. Manufacturers have produced 
dozens of window and glass products 
designed to strengthen school facilities 
against intruders. Because there’s so many 
options on the market, it’s important that 
decision makers can come prepared to 
make informed decisions for their district. 
I’ve spent several years working with 
districts to design safer schools. In my 
experience, the following are the most 
important distinctions between types 
of glass. This information will help you 
choose the most appropriate, and cost-
effective, solutions for your schools. 
Types of Glass
Architectural glass comes in three 
categories, based on how the glass 
behaves when it breaks. 
•	 Annealed Glass
•	 The oldest, and most basic, style 
of glass. 
•	 Breaks into large, extremely 
sharp shards. 
•	 Because broken pieces can cause 
severe injuries, building codes 
have strict rules about where 
you can put annealed glass. 
Clearing Up Security Glass
By: Breanna Kolk, AIA, Bond Architects, Inc
•	 Tempered Glass
•	 Breakable, but instead 
of big shards, it 
shatters into 
small pebble-
like pieces.
•	 Used in car 
windows, 
because 
it can be 
punched out 
during an 
emergency 
escape 
without 
injuring 
occupants. 
•	 Higher levels of 
safety, and more 
complex to produce, 
compared to annealed glass.
•	 Laminated Glass
•	 Glass bonded with a 
polycarbonate layer. 
•	 If glass breaks, the 
polycarbonate holds everything 
together in one piece. 
•	 Used in car windshields. 
•	 More complex to produce than 
tempered glass.
With each increasing level of 
complexity in manufacturing come 
higher costs and longer lead times. 
Safety Glass vs. Security Glass
•	 Safety glass refers to glass that has 
been treated so that it doesn’t break 
into large, sharp shards, which can 
cause severe injuries to building 
occupants. Safety glass can be either 
tempered or laminated glass. 
•	 Security glass refers specifically 
to certain types of laminated glass, 
because it means that an intruder 
won’t be able to immediately break 
a hole through the glass. All security 
glass is laminated glass, but not all 
laminated glass is security glass. 
Because it’s laminated, and holds 
together instead of breaking into 
sharp shards, all security glass is also 
safety glass. But not all safety glass is 
security glass — to successfully keep 
out an intruder, the glass needs to stay 
in one piece. 
Bullet-Resistant vs. Intruder-Resistant
Within security glass, there are two 
main categories. One stops bullets, the 
other stops people.
•	 Bullet-resistant glass does not let a 
bullet pass through the glass. These 
types of glass are incredibly strong 
but are much more expensive. 
Understanding industry terms to choose safe, secure glass for your campus
ADA Room Signs Made Easy
www.indoxservices.com | 314.633.4800
stlorders@indoxservices.com
• ADA/Braille Room ID Signs
• Match Existing Signage
• Custom Colors and Sizes
• Windows for Paper Inserts
• Rebrand or Refresh as Needed
Figure 1 — All laminated glass and 
tempered glass are safety glass, but not all 
safety glass is security glass.

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