When an attacker reaches your building’s perimeter, glass is almost always the first thing they target. Here is what you need to know about upgrading that weak point with glazing engineered to hold.
Table of Contents
Introduction: Why Forced Entry Resistant Glass Matters Today
What Is Forced Entry Resistant Glass?
How Forced Entry Resistant Glass Works During an Attack
Performance Levels, Ratings, and Test Standards
Key Applications for Forced Entry Resistant Glass
Forced Entry Resistance vs Bullet Resistance vs Blast Protection
Retrofit Systems vs New Construction Glazing
Design and Installation Considerations
Benefits Beyond Security: Comfort, Acoustics, and Aesthetics
How to Select the Right Forced Entry Resistant Glass System
Why Choose Our Forced Entry Glazing Solutions
Frequently Asked Questions About Forced Entry Resistant Glass
Conclusion and Next Steps
Introduction: Why Forced Entry Resistant Glass Matters Today
Smash-and-grab theft, organized retail crime, and targeted violence have surged since 2020. U.S. retailers lost an estimated $45 billion to shoplifting in 2024, an 18% year-over-year jump, according to the National Retail Federation. The FBI reports that flash mob shoplifting events stole more than $8 million in goods from 2020 to 2024. In nearly every case, attackers went through glass doors and windows first.
Forced entry means breaking or shattering glass panes, prying or battering doors and windows, and using tools like crowbars, sledgehammers, and bats to create a body passage large enough for a person.
Standard glass has no certified security metrics unlike forced entry glass – traditional annealed glass shatters into dangerous shards, and tempered glass pops into fragments, both failing in seconds under sustained attack.
Modern forced entry resistant glass changes that equation. It can delay intruder access significantly – often five to twenty or more minutes – buying critical time for first responders and internal lockdown procedures.
But glass is only one layer. A complete strategy pairs security glazing with entry resistant doors, reinforced framing systems, access control, surveillance, and well-rehearsed security plans.
What Is Forced Entry Resistant Glass?
Forced entry resistant glazing is specially engineered laminated glass or glass-polycarbonate composite designed to resist a sustained forced entry attack – not just a single accidental impact. It is built to keep occupants safe and protect people and assets behind the glass while an aggressor hammers away.
Key properties that separate it from ordinary safety glass:
- Forced entry glass utilizes a sandwich construction of multiple layers of glass and interlayers – typically PVB, ionoplast, or polycarbonate bonded between glass lites.
- Laminated glass with multiple panes is commonly used for forced entry resistance, creating a system that absorbs repeated blows.
- Polycarbonate is integrated into forced entry systems for enhanced durability, adding impact resistance beyond what glass alone provides.
- Forced entry glass absorbs impact force using strong polymer or polycarbonate interlayers that flex and redistribute energy.
- Un-rated safety glass (tempered, annealed) is designed for accidental breakage safety, not deliberate attack. Forced entry rated glass is independently tested to standards like ASTM F1233 or EN 356. Bullet resistant glass is tested to stop projectiles (UL 752). Blast-resistant glazing focuses on explosive overpressure and fragmentation.
These glazing products are most effective when paired with reinforced frames and forced entry resistant doors to create a continuous, attack-resistant building envelope.
How Forced Entry Resistant Glass Works During an Attack
The primary performance goal is time delay. Every minute an attacker is held outside the building is a minute for alarms to sound, occupants to shelter, and law enforcement to respond. Systems are engineered to stall intruders for defined periods based on the rating level.
How the laminated construction performs under assault:
- When the outer lite cracks, the interlayer holds shattered glass fragments in place. Shrapnel injuries are prevented by internal layers holding these flying glass shards together, denying the attacker a clear opening.
- Forced entry resistant glass can withstand blunt objects and sharp tools. Each successive blow requires the attacker to expend more energy without gaining a passable hole.
- Typical attack tools – sledgehammers, axes, crowbars, thrown bricks, concrete blocks – are specifically accounted for in test protocols. Riot Glass can withstand blows from common vandalism tools, and Riot Glass products can resist attacks from tools like crowbars and bats. DefenseLite protects against crowbars and sledgehammers.
- Some glazing systems undergo forced entry ballistic testing such as ASTM F3561, where the glass is first shot with multiple rounds and then subjected to manual forced entry attack. The system must still resist entry even after ballistic weakening.
- Proper anchorage is non-negotiable. If frames, anchor bolts, or hardware are weak, an attacker can pry or dislodge the glazing system regardless of how strong the glass itself is.
Performance Levels, Ratings, and Test Standards
Independent, standards-based testing lets architects, insurers, and Authorities Having Jurisdiction compare security products objectively. Without a tested rating, claims of entry resistance are marketing, not engineering. Security windows and doors are tested against rigorous standards for forced entry ratings.
Key standards for North American and European projects:
- ASTM F1233 – measures forced entry resistance under multi-stage attacks using blunt and sharp tools across Class I through V. Class V specimens survive dozens of axe strikes and multiple tool impacts.
- ASTM F1915 – evaluates forced entry resistance against various tools, with a focus on polycarbonate and laminated glass fabrications.
- UL 972 – the UL 972 Standard measures burglary resistance using a steel ball drop test (e.g., a 5 lb steel ball dropped from up to 40 ft), simulating high-energy burglary tool impacts. UL 972 addresses burglary-resistant glazing material standards.
- ASTM F3561 – the ASTM F3561 Standard tests glass resilience against active shooter scenarios. It fires 10 rounds into the assembly (including shots aimed at lock mechanisms), then delivers forced entry impacts via a 100 lb pendulum impactor at up to 400 ft-lb. ASTM F3561 measures performance after initial forced entry attempts. Levels 1 through 8 correspond to increasing drop heights.
- EN 356 – a European standard for impact resistance against forced entry, using impact and axe-based test protocols across resistance classes.
“No entry” means no opening larger than roughly six to eight inches in any dimension – too small for body passage. The glass, frame, and hardware must all hold.
Bullet resistance (UL 752 levels) and blast resistance (ASTM F1642) are separate rating categories but can be combined with forced entry ratings in multi-functional glazing systems. Protection levels step up from basic smash-and-grab deterrence for retail stores to higher-grade forced entry ballistic systems for government buildings, banking, and critical infrastructure.
Key Applications for Forced Entry Resistant Glass
Different building types face different threats, and security concerns vary by occupancy. Glazing selection must be context-specific.
- Luxury retail and commercial storefronts – forced entry resistant glass protects high-end retail displays against smash-and-grab theft. After the wave of riot-related break-ins in major U.S. cities starting in 2020, many retailers upgraded exposed surfaces with specialized glazing to provide enhanced protection without resorting to unsightly bars or shutters.
- Hospitality lobbies – hotels need aesthetic openness with hidden security. Forced entry rated glass paired with reinforced glass door assemblies maintains a welcoming feel while addressing riot and disturbance threats.
- Schools and universities – it is ideal for schools, offices, and government facilities. Multifunctional systems can combine forced entry resistance, fire rating, and bullet resistance in a single glazing assembly. One elementary school retrofit combined 120-minute fire rating, Level III ballistic protection, and forced entry resistance into the same entry system.
- Banks and financial institutions – financial institutions face simultaneous threats: forced entry, vehicle impact, and ballistic attack. Combined ratings and alarm integration are standard.
- Government and military facilities – government facilities and police stations require the highest performance tiers, often custom-engineered with blast protection and ballistic resistance layered onto forced entry prevention.
- Data centers, religious, and cultural venues – any building with large glass expanses and high-value contents or large gatherings benefits from enhanced security glazing matched to its threat profile.
Forced Entry Resistance vs Bullet Resistance vs Blast Protection
“Bulletproof glass,” forced entry glass, and blast-resistant glass are related but distinct technologies. Each is tested to different standards against different threat types, and assuming one provides the others is a common and costly mistake.
- Bullet resistant glass (rated to UL 752 Levels 1–8) is designed to stop specified rounds and velocities and prevent bullet penetration. However, forced entry glass is not automatically bullet-resistant unless dual-rated.
- A window can offer strong ballistic resistance without resisting a sustained manual attack, and vice versa. Only systems tested under both forced entry and ballistic performance standards – such as ASTM F3561 – deliver confirmed protection against combined threats.
- Blast protection focuses on minimizing fragmentation from a bomb blast, keeping the glazing anchored in the frame during overpressure events, and controlling chemical agents or debris. This differs fundamentally from burglar or riot scenarios.
- Facility managers should begin with a threat assessment: is the primary risk opportunistic burglary, coordinated forced entry attack, active shooter, or explosion? The answer determines whether you need forced entry prevention, ballistic protection, blast protection, or a combined solution. Budget, code requirements, and building occupancy shape the final selection.
Retrofit Systems vs New Construction Glazing
Many commercial properties and schools cannot fully replace their façades, so retrofittable security glazing shields are increasingly popular. Forced entry glass can be retrofitted to existing structures without removing original windows.
- Retrofit systems – clear polycarbonate or glass-clad panels are mounted over existing glass and attached to existing or supplemental framing, forming a secondary forced entry resistant barrier. A middle school in the Sandy Hook region, for example, installed retrofit shield panels over existing glazing with minimal visual disruption.
- New construction – forced entry resistant glass units and entry resistant doors are integrated into thermally broken aluminum or steel frames from the start, allowing combined ratings (fire, blast, bullet) and better thermal performance.
- Retrofit is typically faster, less disruptive, and more cost-effective short-term. New construction systems offer superior aesthetics, energy efficiency, and the full range of multi-functional ratings.
- Damaged exterior shields can often be replaced without removing the original interior glass – simplifying maintenance and reducing downtime after an incident.
Design and Installation Considerations
Glass alone does not guarantee forced entry prevention. Frames, anchorage, hardware, and surrounding construction must all be coordinated to match the tested performance of the glazing system.
- Frame strength and materials (steel or heavy-duty aluminum), anchoring into the surrounding structure, and compatible locking hardware must meet or exceed the rating of the glass.
- Forced entry rated glass is significantly thicker and heavier than standard glazing. Hinges, closers, floor springs, and door operators must be correctly sized for the added weight.
- Code compliance is critical: balance security glazing with egress requirements, accessibility (ADA), fire rating, and energy code standards, especially in doors and exit corridors.
- Professional installation by trained crews is essential. Improper glazing bites, insufficient fasteners, or weak sealants can dramatically reduce entry resistance and void the tested rating.
Benefits Beyond Security: Comfort, Acoustics, and Aesthetics
Modern forced entry resistance solutions are designed to be as invisible as possible, supporting natural light and transparent architecture rather than creating a fortress appearance. Customers, students, and staff should feel welcomed, not caged.
- Acoustic control – specialized polymer layers in forced entry glass dampen outside noise frequencies, a significant benefit in busy urban environments.
- UV filtering – forced entry glass blocks up to 99% of harmful ultraviolet rays for UV protection, preserving interiors and merchandise.
- Energy efficiency – new insulated forced entry glazing units can incorporate low-e coatings and double glazing, contributing to thermal performance goals.
- Optical clarity – high-clarity interlayers and glass-clad polycarbonate maintain excellent visual quality for retail displays, hospitality lobbies, and offices. Thoughtful design preserves welcoming, human-centered spaces with hidden enhanced protection.
How to Select the Right Forced Entry Resistant Glass System
Start with a structured threat and risk assessment rather than jumping straight to security products. The right system depends on what you are protecting, from whom, and under what constraints.
Key selection factors:
- Building type and occupancy – school vs. retail vs. government dictates regulatory pressure and threat profile.
- Threat level – opportunistic burglary demands different performance than coordinated ballistic attack.
- Required ratings – forced entry, bullet, blast, fire – and whether combined ratings are needed.
- Installation constraints – retrofit vs. new construction, structural load capacity, disruption tolerance.
- Aesthetics – transparency, natural light, and architectural character.
Consult with physical security experts, architects, and code officials early. Coordinate forced entry resistant glass with complementary measures: access control, intrusion alarms, surveillance, and Crime Prevention Through Environmental Design (CPTED) strategies. Document all decisions and retain test reports, certifications, and shop drawings for insurance, compliance, and future reference.
Why Choose Our Forced Entry Glazing Solutions
We specialize in security glazing across commercial applications – from retail stores and financial institutions to schools, healthcare, and government buildings. Our solutions are independently tested and certified to standards including ASTM F1233, ASTM F3561, UL 752, and EN 356.
- In-house engineering support for custom design of doors, windows, storefronts, and curtain walls
- Both retrofit and new construction offerings with the ability to integrate forced entry resistant glazing into existing or planned building envelopes
- Multifunctional systems that combine forced entry resistance with fire rating, ballistic resistance, or blast protection
- Responsive technical knowledge and support from early design through installation, with clear documentation for architects and contractors
- Proven project experience with schools, healthcare, high-value retail, and government facilities
Contact us for a security assessment, specification assistance, or a project-specific quote.
Frequently Asked Questions About Forced Entry Resistant Glass
Is forced entry resistant glass the same as bulletproof glass? No. Forced entry glass is tested to resist sustained manual attack with tools. Bullet resistant glass is tested to stop specific calibers and velocities under standards like UL 752. A system must be dual-rated to provide both forced entry protection and ballistic protection.
How long can forced entry rated glass hold back intruders? Depending on the rating class, systems can resist sustained attack for five to twenty or more minutes. Higher classes under ASTM F1233 survive dozens of tool strikes. The goal is to create enough delay for first responders to arrive.
Can I retrofit my existing windows and doors? Yes. Retrofit shield panels made of clear polycarbonate or laminated glass can be mounted over existing glass with minimal visual change. This is a practical path for schools and commercial storefronts that cannot undergo full façade replacement.
Will forced entry glass change the appearance of my building? Modern security glass uses high-clarity interlayers that maintain transparency and optical quality. Most visitors will not notice the difference. Thickness increases slightly, but the result avoids the fortress look of unsightly bars or opaque barriers.
What maintenance does this type of glazing require? Inspect seals, hardware, frame anchors, and interlayer integrity periodically. Clean glass surfaces with standard methods. If a retrofit shield takes impact damage, it can typically be replaced without disturbing the original interior glass.
Can blast protection or bullet resistance be added to the same system? Yes. Multi-functional glazing assemblies exist that combine forced entry, ballistic, blast, and fire ratings. Standards like ASTM F3561 specifically test combined ballistic and forced entry performance in a single system.
How do forced entry resistant doors relate to the glass? Glass is only one component. Doors must be reinforced with rated frames, locks, and hinges. Glass near lock mechanisms is often targeted, so the entire assembly – glazing, frame, and hardware – must perform as a unified system.
Conclusion and Next Steps
Forced entry resistant glass buys the minutes that matter most during a crisis. Understanding the distinctions between forced entry resistance, bullet resistance, and blast protection – and knowing which standards apply – is essential to making informed decisions that protect people and assets.
No single product solves every security concern. The most effective approach layers forced entry resistant glass and entry-resistant doors with alarms, surveillance, access control, and trained response protocols. Together, these materials and systems create a defense that delays attackers without sacrificing the architectural character of your building.
Ready to take the next step? Request a consultation, send your building plans for a glazing review, or ask for a technical checklist to guide your specification process. Your occupants deserve both safety and spaces that feel open, welcoming, and secure.
