Forced Entry Standards

Forced Entry Standards

The following article is provided as a technical reference to assist architects and security professionals in applying forced entry standards and/or evaluating the vulnerability of existing security barriers in situations where active shooter violence is a primary threat concern. 

Table of Contents

The key performance measure of an anti-personnel barrier is its delay time as determined by adversary tools and methods. Ideally, all barriers defining an independent protective layer (e.g., doors, glazing, locks, etc.) should be designed using the principles of balanced protection and provide delay as required to meet the system performance goal. Like a chain whose strength is defined by its weakest link, a protective layer (e.g., building facade, secure lobby, safe room, etc.) is only as effective as its weakest barrier or most easily exploited bypass.

For many types of barriers (e.g., reinforced concrete walls, glass glazing, etc.), delay time against some entry methods can be estimated by referencing testing data as published in Sandia National Laboratories’ Barrier Technology Handbook.[i] In the late 1970’s, Sandia collated penetration test data about different barrier types and construction variations to serve as a standard reference for security planners in the U.S. Government community. To this day, the Barrier Technology Handbook remains the “gold standard” reference for delay time data regarding many barrier types.

Although Sandia’s Barrier Technology Handbook is a useful reference, there are many barrier types and construction variations common today in commercial and academic facilities that were not tested or documented at the time of publication. Additionally, many methods of entry documented by Sandia have limited application in protecting against an adversary using a firearm as an aid in barrier penetration. For example, Sandia cites the mean delay time for penetrating 1/8″ tempered glass with a blunt tool (hammer) as 0.5 minutes.[ii] In penetration tests our company conducted of tempered glass windows using several shots from a handgun to penetrate glazing prior to impact by hand, delay time was approximately 10 seconds.[iii]

In the absence of reliable delay time data for many barrier types, security planners often need to rely on performance standards and ratings developed by organizations such as ANSI, ASTM, UL, CEN, and others. The best standards for specifying manufactured barrier products in a performance-based physical security design are those that most closely replicate the methods and tools likely to be employed by the defined threat and rate products based on delay time performance.

Several specification standards encompass impact testing and employ delay time performance as the primary basis for rating doors, glazing, and wall systems. Some of these standards include the U.S. State Department’s SD-STD-01.01, ASTM F3038-14, CPNI Manual Forced Entry Standard (MFES), and LPS 1175. [iv][v][vi][vii]

US Department of State SD-STD-01.01

The SD-STD-01.01 test protocol is designed to replicate the conditions of a mob attempting to forcibly penetrate a barrier specimen. The protocol involves a series of ballistic tests against different parts of the specimen (shotgun, 5.56mm, and 7.62 NATO), and forced entry tests involving a team of aggressors conducting a series of attacks against the specimen at different parts with the use of various tools (e.g., ram, sledgehammer, saw, bolt cutters, pry bar, chisel and hammer, etc.). The tools and number of active test personnel varies based on time of test. Specimens are rated according to their timed forced entry-resistance against three attack levels: Five minutes (two test personnel), Fifteen minutes (six test personnel and larger range of tools), or Sixty minutes (six test personnel and greatest range of tools).

ASTM F3038-14 

The ASTM F3038-14 testing protocol is structured similarly to SD-STD-01.01, but with some differences regarding number of attackers, ballistic resistance testing, and rating scale levels. ASTM’s testing approach involves six persons conducting a series of aggressive attacks against the barrier specimen with the use of various tools (e.g., ram, sledgehammer, saw, bolt cutters, pry bar, chisel and hammer, etc.). Different parts of the barrier are subjected to independent timed tests. When an opening large enough for test shape is breached and the object is passed through, the test is concluded.  Specimens are rated according to their timed forced entry-resistance against four levels of attack: Five minutes, Fifteen minutes, Thirty minutes, or Sixty minutes.

CPNI Manual Forced Entry Standard (MFES)

In the United Kingdom, CPNI’s Manual Forced Entry Standard (MFES) uses delay time against forced penetration as the basis for assigning performance ratings. The CPNI standard defines three levels of adversary (Novice, Knowledgeable, and Expert) in alignment with three threat levels (BASE, ENHANCED, and HIGH). Testing under each threat level involves two attackers, and each adversary category defines specific capabilities (e.g., tool sets, skill and experience, product knowledge, etc.). MFES resistance time classifications are defined by describing the threat level and delay time performance in increments from 0-20 minutes.

LPS 1175

The UK’s LPS 1175 also uses delay time as the basis for designating Security Ratings for barrier products including doors, windows, etc. Tests involve a single adversary and eight tool categories (A, B, C, D, D+, E, F, G), including a diverse range of impact, prying, and power tools. Each category references an adversary tactic, skill, tool set, desire to remain covert or overt, and motivation. Warrington Certification’s STS 202 is another standard in the U.K. encompassing similar test protocols and a delay time rating scheme.[viii]

Challenges in applying common specification standards in active shooter planning

Unfortunately, all of the aforementioned standards (SD-STD-01.01, ASTM F3038-14, CPNI MFES, LPS 1175, and STS 202) encompass tests with tools unlikely to be encountered in armed assaults (e.g., sledgehammers, chisels, pry bars, power tools, etc.). Also, the number of test personnel used in SD-STD-01.01 (at higher levels) and ASTM F3038-14 is much greater than realistically expected in armed attacks in Europe or North America. For standards such as these, choosing a barrier by simply matching delay time ratings to literal delay time goals may result in overkill for situations where protection against armed attacks is the principal objective. Although there is nothing wrong with conservative specification when the risk level is high or funds permit, many organizations with limited budgets may be wasting money that could be applied elsewhere.

Other standards employ pass/fail tests as the basis for rating. One example is ASTM F1233-08 (Standard Test Method for Security Glazing Materials and Systems), a common standard for defining requirements against forced entry in the United States.[ix] The ASTM F1233-08 protocol has a ballistic testing component and separate tests for forced entry protection using different tools based on five resistance classifications. Although the ASTM F1233-08 standard has merits for certain applications and includes a test procedure for ballistic resistance, the tool sets and sequence of tests defined in ASTM F1233-08 do not realistically replicate the methods of entry and tools likely to be employed by armed attackers in live assaults.

UL 972

Another American standard, UL 972 (Burglary-Resisting Glazing Material) uses dynamic load testing to simulate burglary attempts by the use of blunt object impact.[x] The UL 972 standard employs two separate procedures for High Impact Testing and Multiple Impact Testing. Both test procedures employ a 5 lb (2.3 kg) steel ball dropped at different heights (single impact at 40 feet and five impacts at 10 feet). UL 972 is not optimal for specifying protection against forced entry in active shooter attacks. First, the testing procedure in UL 972 does not consider the potential fragility of a glass specimen after first being penetrated by firearm projectile. Additionally, dynamic load testing does not provide useful delay time data necessary for determining the effectiveness of a safe room as one of several protective layers in an overall physical protection system (PPS) design. Quantitative performance-based PPS analysis tools, such as the Estimate of Adversary Sequence Interruption (EASI) model, require delay time input values that cannot be inferred from UL 972’s pass/fail type tests.[xi]

EN 1627-1630

EN 1627 and related standards EN 1628, EN 1629, and EN 1630 are commonly used in Europe and elsewhere to specify protective requirements for doors, windows, and similar barriers.[xii][xiii][xiv][xv] Tests performed under these standards include pendulum impactor strikes at various points to simulate a forced entry by kicking or blunt object impact (EN 1629), static load imparted by a mechanically-operated pressure pad system (EN 1628), and timed forced entry using various tools (EN 1630). Specimens are rated into one of six resistance classes based on overall performance against dynamic and static load tests and timed tool tests (e.g., cylinder extraction, cylinder twisting, etc.). Each resistance class relates to an anticipated threat (burglar, tools, and tactics) as defined in EN 1627. Unfortunately, as described previously regarding UL 972, dynamic and static load testing is not useful in a security design based on delay time objectives or collective PPS performance. Additionally, the tool sets defined in EN 1630 are also mostly burglary tools irrelevant during active shooter attacks.

EN 356

EN 356 is another CEN standard related to vulnerability of glazing systems against forced entry methods.[xvi] EN 356 uses a dropped impactor (4.11 kg steel sphere) and separate testing with a mechanically-operated fire axe to simulate burglary methods. Resistance against impact energy (based on height of impactor drop) and number of axe strikes determines the category of resistance. In the author’s opinion, EN 356 is also a suboptimal standard for defining protective requirements in safe room design for similar reasons mentioned in reference to EN 1627-1630 (e.g., tool sets, dynamic load resistance versus delay time, etc.).


Two related standards regarding mechanical locks with application in defining requirements for active shooter protection are ANSI/BHMA A156.2 (Bored and Preassembled Locks and Latches) and ANSI/BHMA A156.13 (Mortise Locks and Latches).[xvii][xviii] The ANSI/BHMA test procedures are designed to certify the durability, function, and strength of mechanical locks and latches against a series of static force and torque tests. Lock sets are classified into three grades (Grade 1-3) according to performance on all tests. Outside the United States, EN 12209 includes many of the same types of tests. Although ANSI/BHMA A156 and EN 12209 do not employ delay time as a basis for rating, they are some of the few standards that specifically evaluate door locksets against physical force. Most other standards related to security of mechanical locks (e.g., UL 437, EN 1303, etc.) evaluate performance against tool-aided methods of entry applicable to burglary (e.g., picking, impressioning, drilling, extraction, etc .) but unlikely to be used in armed assaults.

Some additional standards with potential application in specifying barrier products for use against forced entry include:

    • ASTM F2322 – Physical Assault on Fixed Horizontal Barriers for Detention and Correctional Facilities
    • ASTM F426 – Standard Test Method for Security of Swinging Door Assemblies
    • ASTM F1915 – Standard Test Methods for Glazing for Detention Facilities
    • ASTM F1450 – Standard Test Methods for Hollow Metal Swinging Door Assemblies for Detention and Correctional Facilities

[i] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978.

[ii] Ibid, pp. 16.3-39.

[iii] Critical Intervention Services assisted a window film manufacturer in 2015 in conducting a series of timed penetration tests of unprotected tempered glass windows and glazing reinforced with anti-shatter film. A marketing video produced by the manufacturer displaying a few of these tests is available online:

[iv] SD-STD-01.01, Revision G. Certification Standard. Forced Entry and Ballistic Resistance of Structural Systems. U.S. Department of State, Bureau of Diplomatic Security, Washington, DC, 1993.

[v] ASTM F3038-14, Standard Test Method for Timed Evaluation of Forced-Entry-Resistant Systems, ASTM International, West Conshohocken, PA, 2014

[vi] Manual Forced Entry Standard (MFES) Version 1.0. Centre for the Protection of National Infrastructure (CPNI), N.p.: 2015.

[vii] LPS 1175: Issue 7.2., Requirements and testing procedures for the LPCB approval and listing of intruder resistant building components, strongpoints, security enclosures and free standing  barriers, Loss Prevention Certification Board, Watford, 2014.

[viii] STS 202, Requirements for burglary resistance of construction products including hinged, pivoted, folding or sliding doorsets, windows, curtain walling, security grilles, garage doors and shutters. Warrington Certification Limited, N.p. 2016.

[ix] ASTM F1233-08, Standard Test Method for Security Glazing Materials and Systems. ASTM International, West Conshohocken, PA, 2013.

[x] UL 972, Standard for Burglary Resisting Glazing Material. UL, N.p.: 2006.

[xi] Garcia, Mary Lynn. Vulnerability Assessment of Physical Protection Systems. Elsevier Butterworth-Heinemann, Burlington, MA, 2006.

[xii] EN 1627:2011, Pedestrian doorsets, windows, curtain walling, grilles and shutters. Burglar resistance. Requirements and classification. Brussels: European Committee for Standardization, 2011.

[xiii] EN 1628:2011, Pedestrian doorsets, windows, curtain walling, grilles and shutters. Burglar resistance. Test method for the determination of resistance under static loading. European Committee for Standardization, Brussels, 2011.

[xiv] EN 1629:2011, Pedestrian doorsets, windows, curtain walling, grilles and shutters. Burglar resistance. Test method for the determination of resistance under dynamic loading. European Committee for Standardization, Brussels, 2011.

[xv] EN 1630:2011, Pedestrian doorsets, windows, curtain walling, grilles and shutters. Burglar resistance. Test method for the determination of resistance to manual burglary attempts. European Committee for Standardization, Brussels, 2011.

[xvi] Glass in building. Security glazing. Testing and classification of resistance against manual attack, EN 356:2000. Brussels: European Committee for Standardization, 2000.

[xvii] ANSI/BHMA A156.2, Bored & Preassembled Locks and Latches. Builders Hardware Manufacturers Association (BHMA), New York, NY, 2011.

[xviii] ANSI/BHMA A156.13, Mortise Locks and Latches. Builders Hardware Manufacturers Association (BHMA), New York, NY, 2011.


Anti-Personnel Barrier Materials and Construction

Anti-Personnel Barrier Materials and Construction

The following article is  provided as a design guide and technical reference to assist architects and security professionals in specifying new construction and/or evaluating the vulnerability of present barriers in situations aimed at reducing active shooter risk.

Table of Contents


Barriers Materials and Construction


Partition Design

Ideally, walls defining protective layers (e.g., secure lobbies, safe rooms, etc.) should be designed as full partitions extending floor-to-ceiling to minimize opportunity for easy access through drop ceilings. In high-risk situations or design applications where the intervention of security or police forces is expectedly delayed, full partition walls should be a basic requirement.

In low-risk applications and situations where the primary design objective is to simply frustrate adversary access, drop ceilings may be a justifiable compromise. As described in Part One of this article, armed attackers most often use visually-obvious portals (e.g., doors and windows) as their main pathways for movement. Although entry through drop ceilings is certainly possible, our research has not revealed any active shooter attacks to date where drop ceilings were exploited as a means of accessing people located in locked rooms.

Intrusion Resistance of Walls

In alignment with the principles of balanced protection, walls should ideally resist forced intrusion with similar delay times as doors, locks, and windows. In many commercial and academic facilities, walls protecting rooms commonly designated for use as safe rooms (e.g., offices, conference rooms, classrooms, etc.) are often secured by little more than two layers of gypsum board on wooden studs. Some sources suggest two-layered drywall partitions can be penetrated in 60 seconds by an adversary without use of equipment and 30 seconds with the assistance of hand tools.[1] Despite the poor performance of gypsum board walls, they may be a justifiable compromise in some situations, considering the rare frequency of active shooter attacks where walls have been used as a point of entry into locked rooms. In low-risk applications or situations where budget limits retrofit options, we rarely recommend replacement or upgrade of existing drywall.

In medium-high risk applications and safe room designs with delay time objectives over 45 seconds, walls should be constructed using intrusion-resistant materials. Some options for protective wall construction include reinforced concrete, filled masonry block, expanded metal mesh, and polycarbonate-composite wall panels.

Reinforced concrete walls provide the best delay time performance against adversaries using limited toolsets. According to tests documented by Sandia, 4-inches of reinforced concrete with No. 5 rebar on 6-inch centers will provide approximately 4.7 minutes of delay against penetration with hand tools (including saw).[2] If our threat definition is an adversary relying solely on firearm penetration and blunt object impact, reinforced concrete of any dimensions will provide almost indefinite delay.

Contrary to what many assume, unfilled concrete masonry unit (CMU) block walls provide minimal delay against forced entry and only slightly better performance than drywall against some methods of penetration. According to data published in the Barrier Technology Handbook, the mean delay time for penetrating an unfilled CMU block wall is only 36 seconds by the use of a sledgehammer.[3] Unfilled CMU block walls are also susceptible to damage by rifle projectiles and may crumble when struck repeatedly by gunfire.[4] For better performance in delaying forced entry, CMU block walls should be fully grouted and reinforced with rebar. According to tests documented by Sandia, filled 8-inch CMU walls with No. 5 rebar on 14-inch centers provide approximately 1.4 minutes of delay against penetration with hand tools.[5]

Supplementing exterior drywall layers with a securely attached inner layer of expanded metal mesh is one of the most common methods of retrofitting existing walls for improved resistance against forced entry. Expanded steel constructed of 9-gauge 3/4-inch diamond mesh is a common material specification for this purpose. In this type of wall design, the expanded metal mesh is installed on the inside of the protected room and secured to wall studs by using deep screws and fasteners specially designed for this purpose. The expanded metal barrier layer is then overlaid with gypsum board or plywood. According to Sandia, a wall constructed of two layers of 3/4-inch plywood, two layers of gypsum board, and an expanded metal mesh interlayer can provide as much as 6.5 minutes of delay against penetration with hand tools.[6] Despite the popularity of 9-gauge material as a safe room design specification, money can often be saved by using a lighter mesh without compromising performance. If the threat definition is an adversary equipped solely with a firearm, static and dynamic impact force will be the main mechanisms of penetration, and overall strength of the fastening system will be more important than thickness of the metal fabric.

Several manufacturers currently offer polycarbonate composite wall panel products marketed for security applications. Most products of this type are composed of a thin polycarbonate layer (0.08-0.125 inch) bonded to gypsum or cement board. Manufacturers of polycarbonate composite wall systems are generally cautious about describing the capabilities of these products. Most manufacturers only cite single-impact static force tests up to 3,200 ft-lbf. When addressing impact resistance, one manufacturer cites testing under ASTM D2394-83. However, ASTM D2394 relates to the performance of finish flooring against abrasion, friction, and indentation and offers no insight on protective value. Although the concept of these products is very appealing, their use in performance-based protective design is discouraged in the absence of more reliable and promising test data.

Ballistic Resistance of Walls

One of the best references for specifying construction of bullet-resistant walls is U.S. DoD UFC 4-023-07 (Design to Resist Direct Fire Weapon Effects). [7] According to UFC 4-023-07, walls constructed of 4-inches reinforced concrete, 8-inch filled CMU block (grouted full), and 8-inches of brick will resist penetration by 7.62x51mm ammunition.[8] UFC 4-023-07 also provides ballistic resistance specifications for steel plate barriers. However, at the thicknesses specified by DoD, steel is not a practical option in most indoor design situations due to structural load and construction challenges. 

A number of manufacturers also produce fiberglass wall panels rated for ballistic resistance under UL 752, ASTM F1233-08, and EN 1063.[9][10][11] Minimum specifications for protection against military small arms (5.56mm) would be UL 752 Level 7, F1233 R1, or EN 1063 BR5. More conservative specifications for 7.62x51mm include UL 752 Level 8, F1233 R3, and EN 1063 BR6.

In addition to fiberglass panels, Saab’s Barracuda Soft Armor offers an easy method for upgrading hollow walls into bullet-resistant barriers. The Barracuda Soft Armor is designed as 13mm ceramic balls used as infilling between wall boards. Thickness of the armor-filled wall cavity determines its ballistic resistance capabilities. According to Saab’s product literature, 100mm of Barracuda pellets is the technically-estimated specification for protection against 7.62mm FMJ projectiles and 120mm of Barracuda armor has been technically-verified as ~99% effective in resisting 7.62mm armor piercing ammunition.[12] Although Saab does not cite tested ratings according to UL 752 or EN 1063, 125mm Barracuda armor has been certified as STANAG 4569 Level 3 (7.62x54R and 7.62x51AP).[13]


If the risk level and design approach requires door systems rated for tested delay times, doors certified under SD-STD-01.01, ASTM F3038-14, CPNI MFES, LPS 1175 have been tested against a variety of forced entry methods and often exceed requirements for protection during short-duration armed events. If the threat definition identifies an adversary solely employing firearms and expedient tools, any door certified under SD-STD-01.01, ASTM F3038-14, CPNI MFES, or LPS 1175 will likely far exceed performance as suggested by its certified delay time rating.

Considering the cost of security doors and the number of rooms often desired for availability as safe rooms during armed attacks, many organizations do not have the budget or risk justification required for implementing security doors rated under forced entry standards. In this situation, specification may require choosing commercial door hardware with security features adequate to accomplish the design objective or retrofitting existing doors with cost-consciously selected upgrades for maximum benefit.

Intrusion Resistance of Doors

As a general rule, outward-swinging doors provide the best protection against exterior ramming force due to resistance of the rebate within the frame. Additionally, adversaries attempting to pull open locked outward-swinging doors without the aid of tools are at a great mechanical disadvantage. If rooms earmarked as potential safe rooms feature existing inward-swinging doors, door hardware (e.g., locks, strikes, and frames) should be carefully specified to ensure adequate resistance against ramming force.

Most security doors certified under forced entry standards are constructed of steel. However, indoor rooms potentially earmarked for use as safe rooms in office and academic facilities are often equipped with solid core wood or solid wooden doors. Solid core doors are constructed with a composite wood core and overlaid with hardwood veneer for aesthetic appearance. The times required to penetrate solid core and solid wooden doors using methods likely to be encountered during active shooter attacks has never been published. Considering the materials involved, solid wooden doors are preferable to solid core doors. Nevertheless, for application against a gunman employing impact force without additional tools, solid door leafs (regardless of construction) are unlikely to be the point of failure when compared to the potential vulnerability of locks, strikes, wooden frames, and vision panels.

Doors featuring glass vision panels are often highly vulnerable to forced entry. Tempered safety glass panels only provide about 10 seconds of delay against a gunman. Once broken, the intruder can simply reach through the window and manipulate the inner door handle or lock to gain entry. To limit this vulnerability, vision panels should be no wider than 1.5″ (3.8 cm) or constructed of intrusion-resistant glazing such as laminated glass, polycarbonate, or reinforced with anti-shatter film. If the delay time objective exceeds a few minutes, vision panels should be avoided completely. Although there are door sets rated under LPS 1175 and ASTM forced entry standards which feature vision panels, it is generally impractical to upgrade or replace vision panels on commercial doors to sufficiently achieve more than a few minutes of delay.

In situations where performance objectives exceed 15 minutes of delay or adversaries are expected to possess a diverse toolset, security hinges should be installed on safe room doors to reduce the risk of hinge pin removal or cutting. Security hinges with dog bolts can also aid in reducing vulnerability to some tool-aided methods of entry. All door frames on safe rooms (regardless of application) should be constructed of steel.

If the budget and risk level justify installation of doors rated under security standards, specifications for a basic level of forced entry resistance include EN 1627 RC4+ and LPS 1175 SR2+. For higher levels of protection, specifications using ASTM 3038, SD-STD-01.01, and CPNI MFES provide a more reliable basis for delay time performance.

Ballistic Resistance of Doors

Although the author is not aware of any comprehensive published ballistic tests of common commercial door products, it is safe to assume most commercial steel, wooden, and solid core doors are vulnerable to penetration by military small arms. If safe room design objectives require ballistic protection, doors rated UL 752 level 7+ or EN 1522 FB5+ should be specified. Additionally, all doors rated under SD-STD-01.01 have been tested against penetration by 5.56mm, 7.62x51mm, and 12-gauge shotgun.


 Simplified Locking

As a prerequisite criterion, all mechanical locks on safe room doors should feature thumbturns for ease of locking under stress. In several previous active shooter attacks, critical doors on rooms where people were seeking refuge remained unlocked during the event owing to absence of a key.[14] Additionally, good preparation for active shooter events should anticipate the effects of the Sympathetic Nervous System (SNS) on employee response. During high stress events, the SNS is often activated with impairing effects on cognitive function and fine motor coordination. These negative effects of the SNS can interfere with even simple tasks such as locating and manipulating keys.

Ironically, considering the history of active shooter attacks in American schools, locks classified by ANSI as “classroom function” (mortise F05 and bored F84) are perhaps the worst choice for safe room applications and should be avoided when possible. Classroom function locks are only lockable by a key from the outer side of the door. Not only do these locks require a key, but they also require the occupant to open the door and reach into the hallway to secure the lock.

 Intrusion Resistance of Locks

For protection against entry by buttstock impact and kicking, all lever and knob sets on safe room doors should ideally be rated ANSI/BHMA A156 Grade 1 or have a minimum Security Grade of 4 under EN 12209.[15][16] Mechanical locks rated ANSI/BHMA Grade 1 and EN 12209 Security Grade 4+ have been successfully evaluated under a variety of static force and torque tests.

If the design objective is to simply frustrate access by non-committed adversaries, doors secured only by ANSI/BHMA Grade 1 or EN 12209 Security Grade 4+ latch locksets may be sufficient. However, if the design objective is to delay penetration by a committed adversary or the threat definition includes a diverse range of entry tools, locksets should feature a deadbolt or augmented by the installation of an independent deadbolt lock. In medium security applications, single-point deadbolt locks are often adequate. In situations where greater delay times are required or adversaries are expected to employ improved toolsets for entry, multi-point deadbolt systems provide the best protection.

Surface-mounted deadbolt locks are generally superior to mortise and bored locks in resisting forced entry. Surface-mounted deadbolt locks can incorporate bolts unconstrained by the thickness of doors and require the adversary to entirely penetrate the door leaf to access the lock.[17] Surface-mounted deadbolt systems are also less vulnerable to prying due to the increased force necessary to lever the entire door frame.

Many surface-mounted deadbolt systems designed for high security applications feature auto-bolting locks. Auto-bolting systems lock automatically when the door is closed and often disengage automatically when the inside handle is operated for exit. Manually-bolted surface-mounted deadbolts require a manual unlocking operation to permit exit. Building and life safety codes should be reviewed to ensure permissibility before installing manually-bolted surface-mounted locks. Although some jurisdictions prohibit use of manually-bolted locks on school classroom doors, manually-bolted surface-mounted deadbolts are fully permissible in most locations except when installed on egress doors. This generally addresses most concerns regarding upgrading offices, conference rooms, and similar locations as safe rooms. Under International Building Code 2012, surface-mounted deadbolts are also permissible on egress doors in certain circumstances. For instance, IBC 1008.1.9.4 (Bolt Locks) contains a rule exception for use of surface-mounted deadbolt locks on egress doors with occupant loads of less than 50 persons in Group B (Business Group), F (Factory), and S (Storage) occupancies.[18]

Ballistic Resistance of Locks

Another issue to consider in safe room design is the vulnerability of door hardware to ballistic damage. Although forced entry by ballistic attack against locks and hinges has been rare during active shooter events, a number of incidents have occurred where adversaries forcibly entered/or attempted to penetrate rooms by destroying door locks with gunfire.[19]

The only product certification standard that specifically addresses door locks as a component of ballistic testing is the U.S. Department of State’s SD-STD-01.01.[20] Withstanding a handful of exceptions, most lock manufacturers do not subject standard products to ballistic testing in accordance with protocols such as UL 752 and EN 1522.

Furthermore, Sandia National Laboratories and similar research institutions have not published empirical test data to assist in estimating the ballistic vulnerability of locks commonly used in academic and commercial facilities. In the absence of definitive references, perhaps one of the best sources we have for estimating the performance of common door locks against firearm-aided penetration is the television program MythBusters Special 9 “Shootin’ Locks.”[21] Although the sample size tested by MythBusters was very small, the results of testing suggest that bored deadbolt locks are resistant to single-shot penetration by handgun calibers (9mm and .357 magnum) and vulnerable to defeat by high powered rifle (.30-06 cal.) and 12-ga. shotgun slugs. U.S. Army field manual FM 3-21 also states that a shotgun is effective at defeating door locks.[22] Regarding rifle calibers, FM 3-21 somewhat conflicts with the Mythbusters findings by stating that 5.56mm and 7.62mm “have proved to be virtually ineffective for breaching.”[23] From these limited sources, it’s reasonable to assume most locks will be resistant to critical damage by handguns, definitely vulnerable to shotguns, and susceptible to some rifle calibers (albeit, inconclusive as to exactly which rifle calibers and ammunition).

The best approach to this concern is specification of door sets rated under SD-STD-01.01. An alternative option is employing independent door and lock assemblies rated UL 752 level 7+ or EN 1522 FB5+. Surelock McGill, for example, offers a number of lock assemblies and cylinder guards rated EN 1522 up to level FB7.[24]

For organizations without the budget and/or risk justification to equip safe rooms with door sets rated under ballistic resistance standards, the next best option is installing surface-mounted deadbolt locks on the inside of solid wooden or steel doors. Although most solid wooden and steel pedestrian doors are vulnerable to penetration by small arms, the door material will provide some reduction in bullet velocity and conceal location of the lock to reduce hit probability. Augmenting existing locks with bullet-resistant cylinder guards certified under UL 752 and/or EN 1522 is another possible enhancement. Conventional steel wrap-around door knob plates are not bullet-resistant, but may offer a marginal benefit by reducing projectile velocity. Additionally, bored locks may be preferred to mortise locks due to their smaller target size. As an additional concern regarding mortise locksets, wooden doors may critically weaken when struck repeatedly by gunfire in the location of the mortise pocket due to the thin layers of wood in this area.

Electrified Locks and Access Control Design

If a facility is employing/or planning to use electrified locks on potential safe room doors, careful consideration should be used in configuration of the access control system and hardware specification. Although access control systems offer great versatility in security design, they often suffer from vulnerabilities in real world application, which can be problematic during active shooter attacks.

In many buildings the author has assessed over the past several years, facilities were designed as large workspaces with few offices, storage rooms, or conference rooms suitable for use as safe rooms. In some of these facilities, permissions were broadly granted to employees through the facility’s access control system to allow convenient access to conference rooms and shared offices. During an attack by an insider adversary, doors with broadly applied access privileges will not provide useful protection. Likewise, if the access control system in the facility employs card readers and an outsider adversary recovers an access badge from a fallen employee, all doors with universal access will be compromised.

Another common problem relates to the fail-safe/secure configuration of electrified locking systems. Building and life safety codes universally require that egress doors equipped with electromagnetic locks ‘fail safe’ (unlocked) during fire alarms.[25] Although safe room doors in most situations will not be classified as egress doors, the author has discovered a number of facilities during his consulting activity where all access-controlled doors were universally configured to fail safe due to poor system design. In this situation, all fire alarm pull stations in the facility are ‘virtual master keys’ and would compromise most doors if someone activated a pull handle. This is a very real concern. In a number of previous attacks, fire alarms were manually activated by building occupants to alert others (e.g., 2013 Washington Navy Yard) or used by adversaries to deceptively herd victims outdoors for ambush (e.g., 1998 Westside Middle School, 2013 UCF, 2015 North Africa Hotel, etc.).[26][27]

In addition to fire alarms, electromagnetic locks without emergency power support fail safe automatically during electrical failures. Electromagnetic locks also fail safe by virtue of basic function if electrical lines are damaged (such as during an IED attack). Doors employing mechanical locksets and electric strikes configured to fail secure during power disruption are less vulnerable to compromise by electrical failure and fire alarms, but may be more vulnerable to forced entry than doors solely equipped with mechanical locks. Consequentially, CPNI in the United Kingdom specifically discourages use of electric strike plates on security doors.[28]

 If designated safe rooms are already equipped with electrified locks, all aforementioned concerns can be mitigated by installing independent mechanical deadbolt locks for emergency use.


 As a general rule, window and door glazing should be avoided in high risk situations or applications where designers seek ambitious delay goals. Although there are glazing products capable of high delay times, such systems are quite expensive by comparison to the price of wall construction and doors. In low-medium risk applications and situations where glazing is an unavoidable element of architectural aesthetics, windows should be designed to adequately resist intrusion. As described in part one of this article, adversaries most often focus penetration efforts on visually-obvious portals, and windows are often perceived as a vulnerable point for entry. Consequentially, the performance of glazing should be a top priority and may even exceed the importance of delay provided by barriers along less obvious intrusion paths such as walls, floors, and ceilings. 

Window Dimensions (Unprotected Glass Windows)

In accordance with U.S. DoD recommendations, all unprotected windows on safe rooms should be 96 in2 (619 cm2) or smaller.[29] In addition the U.S. DoD guideline, we recommend that any unprotected glass windows or vision panels within arm’s reach (approx. 36″ or 91.5 cm) of door handles and locks have a width of no more than 1.5″ (3.8 cm).

Intrusion Resistance of Windows and Glazing

If window dimensions do not conform to the aforementioned guidelines, glass should be replaced or upgraded with intrusion-resistant materials. Tempered safety glass is generally only 4-5 times resistant to impact as annealed glass and provides minimal delay against forced intrusion. According to testing documented by Sandia, 0.25 inch tempered glass provides 3-9 seconds of delay against an intruder using a fire axe and the mean delay time for penetrating 1/8″ tempered glass with a hammer is 0.5 minutes.[30] Furthermore, impact testing documented by Sandia did not account for the fragility of tempered glass after first being penetrated by firearm projectile. In penetration tests Critical Intervention Services conducted of 1/4-inch tempered glass windows using several shots from a 9mm handgun prior to impact by hand, delay time was only 10 seconds.[31]

Some intrusion-resistant glazing options appropriate in low-medium risk applications include laminated glass, polycarbonate, and glass reinforced with properly attached anti-shatter film.

Laminated glass is a composite material constructed of two or more layers of glass bonded to a PVB or polycarbonate interlayer. According to Sandia’s test data, 1/4-inch laminated glass provides 18-54 seconds of delay against forced entry by fire axe and the mean delay time for penetrating 9/16-inch laminated security glass is approximately 1.5 minutes by hand tools.[32][33] Most glazing products tested and rated under forced entry standards UL 972 and EN 356 are constructed of laminated glass.

Polycarbonate is another option for intrusion-resistant windows. At thinner dimensions, polycarbonate provides decent impact resistance but comparable performance to tempered glass against fire axe attacks.[34] Polycarbonate truly distinguishes its benefit at thicknesses of 1/2-inch or greater. According to tests documented by the Nuclear Security Systems Directorate, 1/2-inch polycarbonate can delay hand tool penetration for up to two minutes.[35] Sandia cites 2-6 minutes of delay for penetration of polycarbonate by fire axe and sledgehammer.[36] Polycarbonate is relatively inexpensive and can be purchased as sheets and cut to dimensions as needed. The main disadvantages of polycarbonate are its limited resistance to scratch damage and susceptibility to discoloration and degradation from UV exposure.[37] Some tests also suggest polycarbonate may be vulnerable to fragmentation and shatter critically when penetrated by 12-gauge shotgun.[38]

In low risk situations or circumstances where budget does not permit replacing existing glazing, anti-shatter film properly attached and anchored to tempered or annealed glass may be a cost-effective alternative. Regretfully, Sandia never published data on the penetration times of film-reinforced glazing. In 2015, CIS participated in a series of tests of 1/4-inch tempered glass windows with mechanically-attached 11 mil window film. The tests involved penetration by firearm followed by impact (kicking and rifle buttstock). The delay times ranged from 62 to 94 seconds and deviated according to the aggression of our penetration tester.[39] Although the sample size was small, the CIS test times at least provide a reasonable expectation for performance of window film during active shooter attacks. If anti-shatter film is chosen as an upgrade, specifications should require mechanical or cement bond frame attachment.

To facilitate performance in safe room designs with delay time goals over 60 seconds, it is recommended that designers use glazing products rated for intrusion resistance under ASTM F1233-08, EN 356, and EN 1627. If the threat definition identifies firearm penetration and buttstock impact as the primary methods of entry, reasonable specifications include ASTM F1233-08 Class 2+ Body Passage, EN 356 P6B+, and EN 1627 RC4+. UL 972 is another option, but in the author’s opinion should only be specified in low-medium risk applications. See Part 4 of this series for a survey of window protection standards and their relevant merits and disadvantages in safe room design.

Ballistic Resistance and Windows

For ballistic resistance, specifications for protection against military small arms include EN 1063 BR5-BR7, UL 752 Level 7-9, and ASTM F1233-08 R1-R4AP.

Ceilings and Floors

Although penetration through ceilings or floors is possible, such paths of entry are least likely considering typical construction characteristics and adversary behavior as witnessed during previous armed attacks. However, in high risk design applications, floors and ceilings should provide balanced protection according to the safe room’s specified delay time objectives. For this purpose, Sandia’s Barrier Technology Handbook provides a good survey of penetration times for a wide range of ceiling and floor construction variations.[40]


[1] Hypothetical Facility Exercise Data. Hypothetical Atomic Research Institute (HARI). The Twenty-Sixth Annual Training Course. U.S. Department of Energy. N.p. N.d. pp. 48.

[2] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978. pp. 4.2-6

[3] Ibid. pp. 4.5-2

[4] The vulnerability of unfilled concrete block walls to penetration and potential failure by gunfire is well demonstrated by numerous “backyard test” videos posted on YouTube. Most videos posted on YouTube display the vulnerability of stacked block walls without mortar. Finished walls will likely be more resistant to critical failure. Example:

[5] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978. pp. 4.5-2

[6] Ibid. pp. 4.9-1,2

[7] UFC 4-023-07, Design To Resist Direct Fire Weapons Effects. US Department of Defense, N.p.: 2008.

[8] Ibid. pp 5-8

[9] UL 752, Standard for Bullet-Resisting Equipment. UL, N.p.: 2005.

[10] ASTM F1233-08, Standard Test Method for Security Glazing Materials And Systems. ASTM International, West Conshohocken, PA, 2013

[11] EN 1063:2000, Glass in building – Security glazing – Testing and classification of resistance against bullet attack. European Committee for Standardization, Brussels, 2000.

[12] Saab Barracuda Soft Armour. (Product Brochure). Saab Barracuda AB. N.p. N.d.

[13] Ibid.

[14] One example is the December 2017 shooting at Aztec High School. Matthews, Justin. “Substitute unable to lock doors during shooting.” KOAT Action News. 9 December 2017. Accessed 17 December 2017.

[15] ANSI/BHMA A156.13, Mortise Locks and Latches. Builders Hardware Manufacturers Association (BHMA), New York, NY, 2011.

[16] EN 12209, Building hardware – locks and latches – mechanically operated locks, latches and locking plates. European Committee for Standardization, Brussels, 2016.

[17] Door Security. A Guide to Security Doorsets and Associated Locking Hardware. Centre for Protection of National Infrastructure. N.p. June 2013. pp. 20

[18] 2012 International Building Code. Chapter 10 (Means of Egress). International Code Council. N.p. 2012.

[19] Examples include the 2013 shooting at the Santa Monica College Library and a 2015 attack against a hotel in North Africa (details confidential).

[20] SD-STD-01.01, Revision G. Certification Standard. Forced Entry and Ballistic Resistance of Structural Systems. U.S. Department of State, Bureau of Diplomatic Security, Washington, DC, 1993.

[21] MythBusters Special 9. Mega-Movie Myths 2-Hour Special. MythBusters. 2006.

[22] FM 3-21.8, The Infantry Rifle Platoon and Squad. Headquarters Department of the Army. Washington, DC. 28 March 2007. pp. F-20

[23] Ibid.

[24] High performance door solutions. NASL-017. (Product Catalog). Surelock McGill. N.p. 2017.

[25] 2012 International Building Code. Chapter 10 (Means of Egress). International Code Council. N.p. 2012.

[26] After Action Report. Washington Navy Yard. September 16, 2013. Internal Review of the Metropolitan Police Department. Metropolitan Police Department. Washington, D.C. July 2014. pp.14

[27] Harms, A.G. UCF After-Action Review. Tower #1 Shooting Incident. March 18, 2013. Final Report. N.p. May 31, 2013. pp. AAR-14

[28] Door Security. A Guide to Security Doorsets and Associated Locking Hardware. Centre for Protection of National Infrastructure. N.p. June 2013. pp. 27

[29] UFC 4-023-10, Safe Havens. US Department of Defense, N.p., 2010. pp. 42

[30] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978. pp. 16.3-39

[31] Critical Intervention Services assisted window film manufacturer Solar Gard Saint-Gobain in 2015 in conducting a series of timed penetration tests of unprotected tempered glass windows and glazing reinforced with anti-shatter film. The author personally supervised and witnessed these tests.

[32] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978.

[33] Garcia, Mary Lynn. Design and Evaluation of Physical Protection Systems. Burlington, MA: Elsevier Butterworth-Heinemann, 2007.

[34] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978.

[35] Garcia, Mary Lynn. Design and Evaluation of Physical Protection Systems. Burlington, MA: Elsevier Butterworth-Heinemann, 2007.

[36] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978.

[37] Tjandraatmadja, G.F., and Burn, L.S.  “The Effects of Ultraviolet Radiation on Polycarbonate Glazing. Durability of Building Materials and Components.” Institute for Research in Construction, Ottawa, ON. pp. 884-898

[38] Hutson, Bill. Hut’s Ballistic Tests.

[39] Results of original tests conducted by Critical Intervention Services in cooperation with window film manufacturer Solar Gard.

[40] Barrier Technology Handbook, SAND77-0777. Sandia Laboratories, 1978. pp. 16.3-27-16.3-32

Egress Design and The Active Shooter Threat (Pt. 10)

Egress Design and The Active Shooter Threat (Pt. 10)

Egress planning is often regarded as a life safety matter with influence on security, but otherwise a discipline independent from physical protection. However, when preparing facilities for active shooter violence, egress design should be approached as an integral component of our protective strategy.

As discussed in earlier articles in this series, security measures and facility preparations should be carefully designed to augment and anticipate the actions of building occupants. For people located at ground level during an attack or in building locations without safe refuge options, escape (what DHS calls ‘Run’) is the preferred response. To effectively facilitate this response, escape routes should be readily available that permit fast and unobstructed egress to safe outdoor locations away from the facility.

Although all buildings are required to comply with life safety codes related to emergency egress, International Building Code (IBC), NFPA 101, International Fire Code (IFC), and municipal codes often fall short in considering the unique dynamics of evacuation during armed events. Historically, these codes were designed with fire as the focus and don’t fully account for issues such as severe impairment of evacuees due to sympathetic nervous system (SNS) activation, the unpredictable actions of mobile attackers, and lack of situational awareness that may render multiple exit routes unsafe or at least perceived by evacuees as potentially-dangerous.

Many facilities rely on the advice of fire marshals and the results of inspection reports as a measure of readiness. Candidly speaking, this is a major concern. Aside from the inadequacy of current regulations, I often find violations of existing code during my work as a consultant that have somehow survived years of inspection.

So let’s take a walk beyond IBC and NFPA and explore considerations for designing an egress plan optimized to support response actions during active shooter events.

Egress Routes

To ensure building occupants have options for escape regardless of an attacker’s location, alternate egress routes should exist from all normally-occupied areas providing versatile access to safe exits. In most situations, providing two or more alternate egress paths from each occupied area (routed in different directions) is sufficient.

In newly-constructed buildings, identifying alternate egress paths isn’t usually difficult. In facilities constructed before modern building code, options are often limited. 

During the 2008 assault on the Leopold Café in Mumbai, approximately 30 people were eating dinner in a narrow corridor of booths located on the second level when the attack commenced.[1] There was only a single stairwell and no room on the second floor capable of safe refuge. Fortunately for those on the second floor, the terrorists were satisfied after killing ten people and wounding numerous others and never noticed the unlocked door discreetly leading upstairs.

The Bataclan Theater in Paris, attacked by Islamic State terrorists in 2015, was another example of a building with limited escape options. At the time of the attack, there were three exits accessible to the public. One was the main entrance on Boulevard Voltaire and two emergency exits which discharged into an alley on the south-side of the building.[2] With the main entrance blocked by the terrorists’ presence, people located on the dance floor and north-side of the building had no way to escape without passing the attackers’ aim.

Bataclan Theater Exits

Installing new exits is the obvious solution to this problem. However, in situations where there are no options due to adjacent buildings (such as the Bataclan Theater) or similar circumstances, consider upgrading or constructing rooms for safe refuge purposes. As an additional measure, explore options for providing unconventional routes of escape as described later in this article.

The capacity of exits is another matter to consider. In situations where it is predictable that attackers will approach from a specific direction, expect a panicked reaction as everyone seeks to escape away from the gunman’s location. When faced with an imminent threat, people instinctively flee the direction of harm. Now if there are few people in the area, this type of reaction usually poses no special problems. But locations where this concern arises are often highly-populated and confined areas with limited exit options.

As discussed in Part 6 of this series, many armed attacks by outsider adversaries originate through public entrance doors and shooting commences immediately. This behavior has been very consistent in attacks against public buildings such as nightclubs, churches, and museums. In this situation, the natural reaction of people is to flee toward the opposite side of the room often resulting in tripping, trampling, and a bottleneck near whatever exit doors are present.

In some cases, the presence of furniture and other obstructions prohibit many from even reaching the exits. This situation has been especially common in attacks against church sanctuaries where the location of pews often block people from quickly reaching exits in the front of the room.

Church Attack Infographic Diagram

If this concern is foreseen during the initial design phase, solutions are often easy and don’t require major investment. For those with existing buildings, remedy often involves some expense.

If dangerous congestion is predicted at single-door exits, consider enlarging the present exits with the use of double-doors. If enlargement is insufficient or the situation prohibits modifying existing exits, consider installing new exits as illustrated in the following example.

Upgrading Church Sanctuary for Active Shooters

In some cases, the situation can be eased by simply working with what’s available. In several buildings we’ve assessed with this concern, locked doors were present in areas where congestion was predicted providing access to service corridors or private hallways. By unlocking these doors and equipping them with appropriate hardware, we can provide an additional route of escape and ease congestion at the existing exits. However, implementing this solution may require other measures to address new concerns about public access into previously secured areas.

As a final point about escape paths, egress routes should be intuitive and simple to navigate under high-stress conditions. Several years ago I conducted an assessment of a community center building during the final phase of a major renovation. Unfortunately, most construction was nearly finished before we had a chance to offer useful comment. One of my greatest concerns in this situation was the addition of a new building level (earmarked for after-school programs) featuring two stairwells that discharged one level below into a second-floor hallway. After exiting to the second floor, evacuees were required to proceed down the hall to access a different stairwell in order to reach the first-floor exits. Despite the approval of local authorities, this type of complex egress path should be firmly avoided in active shooter planning. In the absence of any alternatives, our advice was to build a robust safe room in the kids’ area with sufficient capacity and train staff that lockdown is their only safe response during an attack.

Exit Signage

Exit signage should be clearly visible inside all work areas and hallways and direct evacuees to the most accessible stairwells or discharge doors. These are obvious points, but this subject is a common problem in many facilities. Where I encounter this issue most frequently is in renovated buildings that have changed their original room configuration or created expansive workspaces with cubicle walls. When facilities reconfigure walls and don’t update exit signage correspondingly, the result is often chaos—Signage directing evacuees to dead ends or locked doors, signage leading into areas with no further direction, locations where no signage is visible, etc.

Exit Signage Problems

Another problem, albeit less common, are situations where signage was incorrect from the beginning. Some time ago, I encountered a facility where the exit signage plan was similar to a puzzle game. Most arrows directed me in a circuitous loop around the outside of the floor and nowhere near the exit stairwells (which were positioned in interior hallways). Realizing I was walking in a circle, I followed alternate directional arrows and found myself at a dead end elevator landing with no nearby exits. Bear in mind, we’ve been conducting assessments of this type for years. If I can’t find my way out of a building, it’s likely a deathtrap during an active shooter attack.

If a building is configured with tall cubicle arrangements or corridors constructed of glass walls, consider placing directional signage on the floor if overhead visibility is a problem. In facilities like this, ceiling-mounted exit signage is often difficult to locate due to obstruction or the hall-of-mirrors type atmosphere often created in narrow corridors lined by glass. In these cases, providing additional signage on floors is often effective.

Emergency Stairwells

Exit stairwells should be well illuminated and clear of obstructions. Although these points are universally mandated under building and fire codes, this is another common area of concern.

On the subject of stairwell lighting, IBC permits illumination levels of 1 fc (10.8 Lux) and NFPA dictates 10 fc (108 Lux).[3] [4] Regardless of your location and regulatory mandates, I strongly recommend adopting the NFPA specification of 10 fc (108 Lux) as a minimum guideline. Over the years, I have assessed a number of facilities (particularly in Europe and the Middle East) where stairwell illumination was so poor I needed to use a flashlight to safely navigate the stairs.

Obstruction is another common problem. In the absence of adequate storage rooms, many facilities resort to stairwell landings as convenient spaces for overflow.

Egress Obstructions at Exit Doors

The location of stairwells is another issue to consider. In armed attacks against multi-floor buildings, the ground-level is often where the attack originates and may be a dangerous location while an event is active. If building occupants are not aware of the exact location of the threat, the combined effects of fear and lack of situational awareness may make people hesitant to evacuate if they need to navigate through interior hallways to access exits. This issue is often compounded further by the effects of the SNS on problem-solving ability.

To address these concerns, emergency stairwells should ideally discharge directly outdoors through exit doors at ground-level. Stairwells that discharge into lobbies or central hallways should be strictly avoided. If a facility has stairwells that discharge into potentially hazardous areas, employees should be warned of which stairwells to avoid as part of their active shooter training.

Stairwell Escape During Active Shooter Events

If an exit stairwell has multiple doors at ground-level, signage should be clearly visible indicating the proper door for discharge. Although this is not a common problem, I occasionally encounter situations where there are multiple doors at the base of a stairwell and no clear indication of which is the proper exit door. In this situation, choosing the wrong door may be a fateful decision.

Another matter to consider is the possibility of stairwells being used by attackers in navigating the building. During attacks inside multi-level structures, adversaries frequently use stairwells to move between levels.  A few examples include attacks at the Virginia Beach Municipal Center (2019), Corinthia Hotel Tripoli (2015), and Washington Navy Yard (2013).[5]

Addressing this concern raises several challenges.

First, it is often cost-prohibitive to install CCTV cameras in stairwells in a manner suitable for tracking movement between floors (and especially in high rise structures). So if we have a control room employing CCTV to monitor the progress of attackers, stairwells are often a blind spot. Second, although IBC permits interior stairwell doors to be locked against entry from the stairwell side, code requires that interior stairwell doors are “capable of being unlocked simultaneously without unlatching upon a signal from the fire command center…[or] signal by emergency personnel from a single location inside the main entrance…” [6] NFPA regulations are different in detail, but the same concern is present. As discussed further in this article, the fail-safe operation of electrified locks is a major concern during active shooter attacks.

To address the possibility of adversaries navigating floors by stairwell, it may be permissible in some locations to install barriers inside existing stairwells featuring secured egress doors and exit bar devices to restrict upward movement. The photo below is an example of this type of barrier using wire mesh and an acrylic panel to prevent manipulation of the door handle. Although I like this approach in concept, code requirements should be carefully assessed before implementing this type of measure.

Stairwell Cage Barrier

If the Design Basis Threat is an outsider adversary and placing barriers inside stairwells is permissible, I recommend installing them between ground-level and the next higher floor. This recommendation is based on the fact that most attacks by outsiders initiate at ground-level. In the case of buildings with interior public staircases providing access to second or third levels (such as a hotel with a mezzanine), the placement of stairwell barriers should be adjusted accordingly.

Exit Doors

Exit doors should be clearly visible and identified by overhead signage. Although this is not a common issue of concern, situations occasionally arise where architects have visually concealed the exit doors to create a unified aesthetic appearance. Following is an image illustrating this concern provided by Lori Greene, Manager of Codes & Resources at iDigHardware (Allegion).

Avoid the use of electromagnetic locks on egress doors!

Although mag locks offer versatile benefit in access control design, they present several problems during active shooter attacks. First, building and life safety codes universally require that egress doors equipped with mag locks fail safe (unlocked) during fire alarms. In this situation, every alarm pull station inside the building is a ‘virtual master key’ and will compromise all doors equipped with mag locks with one pull of a handle.[7] We have had multiple attacks where fire alarms were manually activated by building occupants (e.g., 2013 Washington Navy Yard), activated by smoke or dust (e.g., 2018 Marjory Stoneman Douglas HS, 2008 Taj Mahal Hotel Mumbai, etc.), or used by attackers to deceptively herd victims outdoors for ambush (e.g., 1998 Westside Middle School, 2013 UCF, 2015 Corinthia Hotel Tripoli, etc.).[8] [9] [10]

In addition to fire alarms, mag locks also fail safe if electricity is disrupted for any reason such as an extended power outage or if lines are damaged during an explosion. This is a particular concern in situations where the Design Basis Threat includes terrorists employing body-worn IEDs.

As an added concern, electromagnetic locks require door-mounted exit hardware (e.g., switch, lever, etc.) or alternatively, an exit sensor to unlock egress doors when an alarm is not activated. In many facilities I encounter, solitary wall-mounted push-to-exit (PTE) switches are used for this purpose despite code requirements stipulating door-mounted hardware or exit sensors. Furthermore, PTE switches used for this purpose are often small in size and easily overlooked when people are trying to escape under high stress conditions. Poor placement of PTE switches compounds this problem even further. During assessments, I often find PTE switches mounted away from doors in a manner that requires evacuees to stop and scan the area for a switch.

As a tragic example of this concern, in the 2019 shooting at the Al Noor mosque in Christchurch, 17 people were killed while trapped at an exit door operated by a PTE switch. [11] It is unclear from news reports whether the door failed to open because of an electrical problem or if there was difficulty by evacuees in locating and operating the PTE switch.

Exit sensors for mag locks often pose a different problem. If an exit sensor is placed above doors in a high traffic area, every time someone passes the sensor the door is unlocked. I’ve encountered many facilities where intrusion was as simple as waiting outside a door for a few minutes and listening for a click.

An even greater concern is when facilities opt not to install PTE switches or exit sensors on doors as a means of restricting use for fire evacuation only. The image below displays a bank of controlled exit doors at the entrance of an expo hall. To direct patrons to a nearby revolving door, the facility management decided (in violation of code) not to install PTE switches or exit sensors. When I inquired about this matter, I was assured that the fire alarm and/or control room operator would disengage the doors during an emergency. Nevertheless, if the operator is disabled or delayed in responding to an attack, the consequences of mass evacuation through this area would be tragic.

For access control purposes, we generally recommend using electrified panic bar devices or electric strikes with mechanical hardware. During an evacuation, electrified exit bar devices operate identically to mechanical exit bars—push the bar and the door opens. Aside from ease of operation, doors equipped with electrified exit bars and electric strikes can remain secured during power disruption and fire alarms (withstanding stairwell doors and other situations as defined by code).  

As a final point about access control, avoid the use of delayed egress on exit doors. Many facilities employ egress delays (15-seconds or 30-seconds) as a means of discouraging occupants from exiting through doors reserved for emergency purposes. Although egress delays are often useful for channeling occupants to designated exits, any measure which delays escape during an attack increases the risk of avoidable casualties.

The following video illustrates how long 30 seconds is while standing at an exit door during an active shooter attack.

Unconventional Exit Options

When normally discussing the topic of egress, ground-level exit doors are presumed to be the main points of building discharge. However, during active shooter events, there are often many opportunities for escape that don’t meet the standards of fire code.

For people located on higher building levels, it is often safer to escape upward toward the roof than downward through stairwells. During the 2015 Charlie Hebdo attack, employees of a company located on the third floor above the Charlie Hebdo office sought safety on the rooftop due to concern about gunfire penetrating their office. In the 2004 attack at the Oasis Compound in Saudi Arabia, two people hid on a roof for two days before rescue. Several employees at Washington Navy Yard’s Building 197 also took refuge on a roof rather than risk harm below.[12]

As part of active shooter training, advise employees about the availability of the roof as a safe area. And if the roof is presently locked, consider placing an escape key near all rooftop doors specifically for use during an active shooter event. If safety concerns override the decision to place escape keys near doors, consider installing electrified locks on the rooftop doors that can be released through a lockdown event macro programmed in the building’s access control software.

Roof Top Escape Key

During an attack, any window less than three stories or aperture large enough to crawl is a potential route of escape. In the 2007 shooting at Virginia Tech’s Norris Hall, students in Room 204 escaped by jumping out the second story windows of their classroom.[13] During the 2016 siege at the Pulse nightclub, eight people escaped through an air conditioning vent with police assistance. In the 2013 attack at the Westgate Shopping Mall, people in a restaurant also escaped by crawling through an air vent.

Window Escape During Active Shooter Attacks

If our present building has windows and other unconventional escape opportunities, make note of these options and advise employees during active shooter training. Simply mentioning the examples already cited in this article calls attention to the possibilities and provides a point of reference if employees ever find themselves trapped during an attack.

Now if we are working with an existing structure, it usually doesn’t make sense from a cost-benefit perspective to install new windows or make other building alterations specifically to facilitate unconventional modes of escape. An exception to this might be situations like the Bataclan Theater (described earlier in this article) where the absence of exits is a major concern and there are no options for remedy.

When designing new facilities, consider placing windows in select locations where it is likely people will be trapped during an attack. One example is public restrooms. Although public restrooms rarely feature door locks, they are commonly used by people seeking refuge during active shooter attacks. If we anticipate this problem and the restroom is adjacent to an exterior wall at ground level, install a 24” tall horizontal sliding window just below the ceiling to provide anyone trapped in the restroom with a possible means of escape. If this had been done at the Pulse nightclub, thirteen people might be alive today.[14]

[1] Details provided by a confidential source during the author’s visit to the Leopold Café in 2016.

[2] Details confirmed during the author’s visit to the Bataclan Theater in 2018.

[3] 2015 International Building Code. Chapter 10 (Means of Egress). International Code Council. N.p. 2015.

[4] NFPA 101 (1)

[5] After Action Report. Washington Navy Yard. September 16, 2013. Internal Review of the Metropolitan Police Department. Metropolitan Police Department. Washington, D.C. July 2014.

[6] 2015 International Building Code. Chapter 10 (Means of Egress). International Code Council. N.p. 2015.

[7] As a caveat to that statement, NFPA 101 states that the pull stations don’t have to unlock the doors: The activation of manual fire alarm boxes that activate the building fire-protective signaling system specified in shall not be required to unlock the door leaves. (Comment by Lori Greene, iDigHardware)

[8] Initial Report Submitted to the Governor, Speaker of the House of Representatives and Senate President. Marjory Stoneman Douglas High School Public Safety Commission. January 2, 2019.

[9] After Action Report. Washington Navy Yard. September 16, 2013. Internal Review of the Metropolitan Police Department. Metropolitan Police Department. Washington, D.C. July 2014.

[10] Harms, A.G. UCF After-Action Review. Tower #1 Shooting Incident. March 18, 2013. Final Report. N.p. May 31, 2013.

[11] “’It doesn’t open’: Christchurch mosque survivors describe terror at the door” Stuff. March 28, 2019, Accessed 25 March 2020.

[12] After Action Report. Washington Navy Yard. September 16, 2013. Internal Review of the Metropolitan Police Department. Metropolitan Police Department. Washington, D.C. July 2014.

[13] Mass Shootings at Virginia Tech. April 16, 2007. Report of the Review Panel. Virginia Tech Review Panel. August 2007.

[14] Harris, Alex. “New details emerge about where the victims of the Pulse massacre died.” Miami Herald. June 14, 2017, Accessed 13 March 2020.