Crisis Architecture: Building to Defend Against Active Aggressors


Daveed Gartenstein-Ross and Tadd Lahnert

War On The Rocks

In December 2012, a gunman shot out the glass front doors of Sandy Hook Elementary School in Newtown, Connecticut. He entered the building intent on killing as many staff and students as possible. Teachers did what they could to lock down their classrooms, but the design of the building rendered their efforts essentially futile. They couldn’t even lock the doors of their rooms from the inside: Somebody would have to walk down the hall and lock the doors from the outside, one by one. The shooter moved too fast for that to happen. He killed 26 students and teachers, 23 of whom were in those nearly indefensible classrooms.

It is striking to compare current figures for these kinds of attacks to those that the United States experienced two decades ago. In 2017 and 2018, 197 people died in mass shootings in the United States, compared to 23 in 1997 and 1998. Despite massive protests and vigorous activist groups like the “March for Our Lives” movement, it is highly likely that these tragedies will continue to occur.

A consistent feature of these attacks is that they are over quickly. At Sandy Hook a single shooter killed 26 children and adults in ten minutes. During the 2016 terrorist attack at the Pulse nightclub in Orlando, Florida, a gunman killed 49 people in nine minutes. If the 2017 Las Vegas shooting is removed from the data set because it occurred outdoors, America’s remaining five deadliest active aggressor events (that is, incidents where an individual is actively engaged in attempting to kill people in a confined or populated area) left 154 people dead in a 49-minute span. The average time between an attacker entering a structure and the end of the shooting was a mere 9 minutes and 48 seconds.

When so much blood is spilled so quickly, every tool should be brought to bear. Communities should look beyond rapid police response or individual heroics to maximize survivability; their efforts should include the design of the structure where an attack may occur. This article introduces an architectural paradigm we call crisis architecture, which one of this article’s authors has been developing over the past four years. It incorporates integrated tactical, psychological, and technological security measures, while preserving the function and aesthetics of buildings to which these measures are applied. The focus of this paradigm is designing the built environment in a way that increases the likelihood that individuals will survive an active aggressor incident.

Social Challenges and Architecture: A Long History

The design of public structures has long been influenced by social challenges facing the communities in which they are built. European architectural landmarks, to give one example, reflect the centuries-old sway that societal troubles have had on the form and function of communal space. In the pre-medieval era, the threat of raiding parties led to the development of primitive hill forts. When the Middle Ages arrived, landed barons confronting routinely violent conditions, such as rebellions and political warfare, built castles to protect themselves and their interests. As politics became less physically turbulent, civil governments constructed stately administrative buildings epitomizing function and grandeur, a phenomenon that has persisted.

Contemporary thinking about designing the built environment to mitigate the effects of social challenges has its roots in concepts developed in the 1960s and 1970s. In 1961, Jane Jacobs penned a famous treatise, The Death and Life of American Cities, that played a pivotal role in shaping public thinking about how the design of cities can influence social outcomes. Jacobs was critical of the post-World War II reshaping of urban areas, where slums were bulldozed rather than revitalized, and large highways replaced old neighborhoods in many downtown districts. Jacobs argued that thoughtful restoration could increase a community’s cohesion and economic viability, and she described mechanisms by which design could contribute to public safety. Jacobs advocated for multi-use neighborhoods consisting of dense collections of shops, restaurants, and street-facing family homes (as opposed to apartments with interior hallways), all connected by a network of clean sidewalks. Such organization was intended to increase the number of people physically out in the community, which would in turn deter criminal activity. Jacobs called this “eyes on the street.” Her ideas were utilized throughout the 1970s, influencing how cities like New York and Toronto look to this day.

A subsequent body of work was developed by the American architect and city planner Oscar Newman in the early 1970s. He formulated the concept of “defensible space” after conducting a series of studies on urban public housing projects. The core of Newman’s theory — which built on Jacobs’s “eyes on the street” — was that a relationship existed between design features and the prevalence of crime at a housing complex. He argued that underused and poorly maintained public spaces, entrances that are not visible from the street, numerous exit points that could act as escape routes, and poor surveillance increased the potential for criminal activity.

Newman’s work became influential, receiving an endorsement in the 1990s from the U.S. Department of Housing and Urban Development, which utilized many defensible space concepts in its policy development and research division. Newman’s ideas were also integrated into the most widely adopted modern theory about the intersection of architectural design and security, Crime Prevention Through Environmental Design.

This model was originally derived from Newman’s theories about defensible space, but in the decades since its introduction it has developed into a comprehensive, practical, and widely implemented independent concept. Academics and practitioners have defined three key strategies to facilitate implementation of Crime Prevention Through Environmental Design into the built environment. The first, natural surveillance, allows neighborhood occupants to increase their awareness of who is present. This is essentially a reinterpretation of the “eyes on the street” concept that includes windows facing the street, front porches on houses and businesses, and sufficient lighting on roads, alleys, and parking lots. The second strategy is natural access control. It creates barriers, real and perceived, that inhibit the ability or desire of a potential criminal to access an area through the use of building entrances, road placement, gates, walls, and foliage. The third strategy, territorial reinforcement, uses design features like fences, patterned pavements and walkways, and landscaping to discourage crime. Practitioners of Crime Prevention Through Environmental Design use a combination of natural (design-based), mechanical (technology- and device-based), and organizational (personnel- and management-based) means. These principles have been embraced by governments, businesses, and individuals, and are regularly used in private and public construction throughout the world.

“Eyes on the street,” defensible space, and principles of environmental design are meant to mitigate social challenges (particularly urban crime) using design. While a critical place for these paradigms remains, the increasingly frequent occurrence of active aggressor incidents, including terrorist attacks, suggests that new techniques are necessary.

New Architectural Paradigms for New Social Problems

Just as urban crime produced new ways of thinking about how design can contribute to security, we believe new challenges should produce another paradigmatic advance. Some aspects of existing paradigms, like surveillance and access control, are useful as starting points, but they are neither comprehensive nor satisfactory solutions. Crime deterrence principles are generally ineffective against terrorists or other active shooters who are driven to commit violent acts with little regard for their own lives.

Governments, architects, and the urban planning community have begun to develop new design strategies to mitigate the risk of some types of terrorist attack, particularly those that employ explosives. Following the 9/11 attacks, many cities — including Washington, D.CNew York, and Los Angeles — implemented ad hoc defensive measures around key infrastructure, buildings, and landmarks. This included installation of concrete barriers. Such measures frequently eclipsed the form and function of the architecture they were installed to protect by unnecessarily impeding vehicular and pedestrian movement, detracting from the vitality of public space, and creating eyesores. They were also found to be generally ineffective, as concrete barriers that are not secured into pavement cannot stop most moving vehicles.

Governments, architects, and urban planners recognized these flaws, and have begun developing design-based paradigms to prevent and mitigate the effects of attacks against high rise buildingsattacks using vehicles, and street-side bombings. The focus of these paradigms can broadly be termed “external area defense.” They are typically focused on a whole city or on a city block. These paradigms are primarily designed to prevent an attack that occurs exterior to a building. Some examples include architectural guidelines from the National Institute of Standards and Technology to help prevent high rise collapse, and a book published by the Federal Emergency Management Agency, Site and Urban Design for Security, that includes hundreds of recommendations for effective, visually appealing, external physical security measures. These paradigms facilitate the integration of security measures directly into the built environment. They allow buildings and public spaces to be more secure while, importantly, maintaining functionality and aesthetic appeal. However, these defenses are not effective once an active aggressor has passed through the area where they have been employed, and into a target building.

Ad hoc defensive structures are giving way to more effective, aesthetic methods to counter terrorist threats.

While advances are being made to develop design paradigms to mitigate the impact of large-scale terrorist attacks like 9/11, comparatively little effort is occurring to counter acts of active aggression. These incidents have occurred at schools in Columbine, Sandy Hook, and Parkland, Florida. They happen at workplaces, like in the Washington Navy Yard or the terrorist attack in San Bernardino. The shooting attacks that struck the Tree of Life Synagogue in Pittsburgh, Pennsylvania, the Emanuel African Methodist Episcopal Church in Charleston, South Carolina, and the Sikh Temple of Wisconsin in Oak Creek show that even houses of worship are not immune.

Developments to mitigate the effects of active shooter incidents remain in much the same state as developments to protect against terrorism in the years immediately following 9/11. School security provides a poignant example. Schools across the country are spending billions of dollars to retrofit existing buildings with ad hoc security measures, but regulations and recommendations to focus their efforts are inconsistent. A lack of academic study on what works, concerns about student privacy, fears about creating a fortified environment that makes students uneasy, and high costs have created uncertainty and hesitation for school boards and administrators. But future public structures and spaces may be able to avoid this problem by employing an integrated, security-conscious design paradigm that incorporates security measures starting with the blueprints.

Employing an integrated set of principles when designing new public spaces or retrofitting existing ones provides a number of advantages to implementing independent security features in an ad hoc fashion. First, the design can be comprehensive and systemic. Rather than independent solutions designed to fill individual security gaps, a structure designed with security in mind can integrate its security measures together. Second, a well-designed building can provide security while maintaining the functional capabilities of the space as it was intended. Third, a space designed with integrated security measures will be able to maintain the form of the architecture as it was envisioned. It will incorporate security features into the plans, making them less obtrusive. A final advantage is that such a paradigm can prevent users from getting the impression that the area is a fortress. A building with security features bolted on after the fact often looks like a fortress, and emphasizes that the potential threat is high, eliciting an emotional fear response that can have negative impacts on performance and productivity. Crisis architecture is intended as a paradigm to help guide the development of future public structures (though it can also be useful in retrofitting existing ones). It provides a method of increasing survivability during attacks where existing “external area defense” paradigms are rendered ineffective through the aggressor’s choice of tactics.

The Eight Principles of Crisis Architecture

Crisis architecture focuses on designing structures in the built environment in a manner that increases the likelihood that individuals will survive an active aggressor incident. Schools, government buildings, houses of worship, commercial structures, and other potential targets can utilize its principles to increase survivability. The concept is modeled around eight principles. The implementation of any one principle would be beneficial, but the full integration of all eight provides the most robust physical defense.

1) Enable Creation of Distance: Structures should allow people in the building to move rapidly from one area to another, which is critical in the initial moments of an active aggressor incident. There should be numerous connecting hallways between parts of a building and multiple staircases between floors, all of which facilitate short transit times. The Pentagon is a building that does this well: Though it is the world’s largest office building, the average time to walk between any two places inside is only seven minutes because of numerous internal corridors and stairwells. Creation of distance has four purposes: to allow potential victims to quickly flee from the immediate vicinity of an attacker, to enable rapid movement to a building exit, to facilitate access to a shelter-in-place location, and to decrease law enforcement reaction time.

2) Allow Safe Exit from Numerous Points in the Building: Integrating numerous exits into the plan for a building will both prevent individuals from becoming trapped in a particular space and ease congestion that occurs when evacuating congested spaces. Standard exits are one way to accomplish this goal, but non-standard exit points, such as pop-out windows, emergency rope ladders for upper story windows, and subterranean exits, are part of a comprehensive blueprint. In a classroom during the 2007 shooting at Virginia Tech, a professor braced the door, allowing ten of the 16 students in the room to exit by the windows and drop into the bushes below.

3) Incorporate Angles to Limit a Shooter’s Line of Sight: An attacker with a firearm will normally shoot only what he can see. Public space design should eschew long straight hallways where people have no place to avoid being seen, and rooms where most of the floor area is directly visible from the door. The integration of hallways with a number of turns and visually appealing barriers that limit line of sight can decrease the number of targets a shooter has available at any given time. By providing space where people can avoid being seen, barriers to line of sight increase the amount of time it takes a shooter to locate targets. This time can be used by civilians to exit the building or move to a shelter-in-place location.

In the six minutes of the shooting at Marjory Stoneman Douglas High School, the shooter killed 17 people and wounded another 17, all without leaving the main hallway. He never entered a classroom because he didn’t need to. He could see and engage every victim either in the hallways or from classroom doors. A design incorporating fewer long corridors with classrooms branching off them might have complicated the aggressor’s ability to target students.

4) Provide Adequate Cover and Concealment: Design elements that provide cover and concealment are central to the crisis architecture paradigm because they facilitate the creation of distance as people move to exit a facility, and provide protection for those who shelter in place. Cover can stop bullets, while concealment only prevents an individual from being seen. Designers wishing to incorporate cover elements could use walls constructed of bullet resistant materials, hardened artistic or structural features (fountains or support beams), or ballistic doors and windows. Non-bullet resistant structural elements (like standard walls or doors) and standard artistic features (such as large plants, half walls, or furnishings) can provide concealment. Another possible concealment technique is using obscuration through a medium like smoke. For example, smoke emitters could be triggered by a nearby gunshot or a responsible party pressing an alarm, as is already in place at some American schools.

During the attack in San Bernardino on Dec. 2, 2015, at least one victim was hit by bullets passing through non-resistant walls. A second was hit when bullets penetrated a non-ballistic glass door. Standard construction and many traditional design features provide insufficient cover and concealment for an active aggressor incident.

5) Enable Rapid Hardening of a Facility: As we noted, the majority of casualties in mass shooter incidents are inflicted in a short amount of time after the attack begins. A design that allows rapid hardening of a facility can alleviate this dynamic. Features that can rapidly harden a structure include pushbutton deadbolts, window coverings that drop when an alarm is triggered, and internal ballistic doors (like existing fire doors) that can be electronically closed. These measures could be controlled individually, such as by teachers who can push a button in their classrooms, or centrally, by a school administrator or security official. Rapid hardening allows a building to maintain its full form and function until defense against an aggressor becomes necessary. When it does, the attacker can be quickly isolated from potential targets.

As we noted earlier, at Sandy Hook Elementary School classrooms could not be locked from the inside: They could be locked only by using keys from the hallway side of the door. The teachers had no ability to harden their rooms, and the consequences were devastating. Had those teachers been able to lock down their rooms when they heard the gunfire, or had an administrator been able to do this centrally, lives may have been saved.

6) Implement “Human-Centered Design” Concepts: Often the victims of active aggressor incidents are untrained and unprepared. These incidents are always chaotic and confusing, and people react instinctively. Innate fight, flight, or freeze responses tend to drive behavior. Human-centered design can help by increasing understanding of the most likely course of action people will take. Buildings using the crisis architecture paradigm should be designed to work with human instincts to maximize safety in a moment of excessive adrenaline and minimal rational thought. There are many creative ways to do this, including using the architectural lines of a building to focus people toward exits, lighting exits in a way that draws attention, and using color and shape to make cover obvious.

Royal Society Study of neurobiological mechanisms found that “in stressful situations, most people tend to fall back on primary ‘freeze–fight–flight’ tendencies and have great difficulty controlling their actions.” Observations of numerous mass shootings reinforce that, in nearly every case, potential victims’ natural instincts take over. A common reaction is to hide under or behind the closest piece of furniture or to run haphazardly, without a real objective other than escape. By utilizing one natural process in the human brain (the ability to observe natural patterns and environmental indicators) to influence a second (fight, flight, or freeze), design can enhance the instinctive human desire to survive an attack.

7) Training and Design Need to be Mutually Supporting: In cases where people receive active aggressor response training (e.g. schools, some businesses and government facilities), training and architecture should be mutually supporting. For example, if an organization’s active shooter protocol is to shelter in place, the spaces where they are supposed to do so should be built to withstand attempted entry or attack. The doors should have secure locks that can be activated from inside rooms, and the walls should be able to stop bullets. Similarly, if evacuation is the preferred protocol, there needs to be cover and concealment available along routes to multiple exits, and there should be a system that allows individuals to know where the shooter is before they start moving, to prevent them from moving directly into his path.

8) Integrate Systems to Increase the Situational Awareness of First Responders: The efficiency of law enforcement response to an active aggressor situation can be degraded if law enforcement lacks sound information about the location of the attacker, the location and condition of victims, or layout of the building. Builders should install systems that decrease the amount of time it takes for first responders to gain situational awareness, thus decreasing their reaction time. These could include internal gunshot detection technology to relay the position of gunfire, systems to allow victims to report the location of the shooter, and small lights (red/green) near doors and external windows to indicate if somebody in the room is wounded. Building administrators could also give first responders temporary access to security cameras.

We do not take a stand on the numerous policy and procedural debates taking place about police responses to mass shootings, but we believe that any law enforcement reaction will be less effective if the police struggle to understand what is happening before, during, and after they arrive. At Marjory Stoneman Douglas High School, police were not authorized to access the school’s surveillance camera system until they were on-site. They also did not know that the footage they were seeing in the security office was on a delay. The shooter left the scene while officers were still viewing what they believed to be live footage of him inside the building. This misinformation hindered the law enforcement, victim rescue, and medical response. Increasing the information available to first responders will increase their effectiveness.

Changing the Paradigm

There is a long history of using design to address social problems, and today’s challenges require this practice to evolve yet again. The crisis architecture paradigm can mitigate the effects of active aggressor attacks that result in mass casualties. By utilizing the eight principles we describe, architects and structural engineers can construct public spaces where physical design works to increase survivability, while maintaining the form and function of the built environment. Crisis architecture provides another level of risk mitigation in a physical space that is not currently covered by existing “external area defense” design paradigms. While crisis architecture is not a panacea for casualties in active aggressor attacks, we believe that it is an unfortunately necessary measure at a time when a lack of comprehensive solutions ensure that these attacks will continue.


Original article contains an image. To read the original article click here.


Daveed Gartenstein-Ross is the chief executive officer of the private firm Valens Global, which has twice been named to Entrepreneur Magazine’s E360 list of the top small businesses in the United States. His previous positions include senior advisor to the director of the Department of Homeland Security’s Office for Community Partnerships, adjunct assistant professor in Georgetown University’s security studies program, fellow at Google’s think tank Jigsaw, and senior fellow at the Foundation for Defense of Democracies. Tadd Lahnert is a fellow at the Combating Terrorism Center at West Point and an active duty Army infantry officer who is currently pursuing a Masters degree at Duke University through the Downing Scholars Program. In the summer of 2019, Major Lahnert served as a research fellow at Valens Global. The views expressed in this article are solely those of the authors, and do not reflect any policy or position of Duke University, the U.S. Army, Department of Defense, or U.S. Government.

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