Physical security

Canadian Embassy in Washington, D.C. showing planters being used as vehicle barriers to increase the standoff distance, and barriers and gates along the vehicle entrance

Physical security systems for protected facilities are generally intended to:^[2][3][4]

• deter potential intruders (e.g. warning signs, security lighting and perimeter markings);
• detect intrusions and monitor/record intruders (e.g. intruder alarms and CCTV systems); and
• trigger appropriate incident responses (e.g. by security guards and police).

It is up to security designers, architects and analysts to balance security controls against risks, taking into account the costs of specifying, developing, testing, implementing, using, managing, monitoring and maintaining the controls, along with broader issues such as aesthetics, human rights, health and safety, and societal norms or conventions. Physical access security measures that are appropriate for a high security prison or a military site may be inappropriate in an office, a home or a vehicle, although the principles are similar.

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Standoff distance

Standoff distance

Standoff distance is a security term that refers to measures to prevent unscreened and potentially threatening people and vehicles from approaching within a certain distance of a building, car, or other shelter, roadblock or other location, or to a person such as a law enforcement officer or VIP, or to a friendly area / location.

Security lighting

Security lighting

In the field of physical security, security lighting is lighting that intended to deter or detect intrusions or other criminal activity occurring on a property or site. It can also be used to increase a feeling of safety. Lighting is integral to crime prevention through environmental design. A 2019 study in New York City found that the provision of street lights, an important type of security lighting, resulted in a "36 percent reduction in nighttime outdoor index crimes."

Aesthetics

Aesthetics

Aesthetics is a branch of philosophy that deals with the nature of beauty and taste, as well as the philosophy of art. It examines aesthetic values, often expressed through judgments of taste.

Human rights

Human rights

Human rights are moral principles or norms for certain standards of human behaviour and are regularly protected in municipal and international law. They are commonly understood as inalienable, fundamental rights "to which a person is inherently entitled simply because she or he is a human being" and which are "inherent in all human beings", regardless of their age, ethnic origin, location, language, religion, ethnicity, or any other status. They are applicable everywhere and at every time in the sense of being universal, and they are egalitarian in the sense of being the same for everyone. They are regarded as requiring empathy and the rule of law and imposing an obligation on persons to respect the human rights of others, and it is generally considered that they should not be taken away except as a result of due process based on specific circumstances.

Prison

Prison

A prison, also known as a jail, gaol, penitentiary, detention center, correction center, correctional facility, lock-up, hoosegow or remand center, is a facility in which inmates are confined against their will and usually denied a variety of freedoms under the authority of the state as punishment for various crimes. Prisons are most commonly used within a criminal justice system: people charged with crimes may be imprisoned until their trial; those pleading or being found guilty of crimes at trial may be sentenced to a specified period of imprisonment. In simplest terms, a prison can also be described as a building in which people are legally held as a punishment for a crime they have committed.

Deterrence methods

The goal of deterrence methods is to convince potential attackers that a successful attack is unlikely due to strong defenses.

The initial layer of security for a campus, building, office,, or other physical space uses crime prevention through environmental design to deter threats. Some of the most common examples are also the most basic: warning signs or window stickers, fences, vehicle barriers, vehicle height-restrictors, restricted access points, security lighting and trenches.^[5][6][7][8]

Physical barriers

Spikes atop a barrier wall act as a deterrent to people trying to climb over the wall

Vehicle barrier at the US Mexico border, 2010.

Physical barriers such as fences, walls, and vehicle barriers act as the outermost layer of security. They serve to prevent, or at least delay, attacks, and also act as a psychological deterrent by defining the perimeter of the facility and making intrusions seem more difficult. Tall fencing, topped with barbed wire, razor wire or metal spikes are often emplaced on the perimeter of a property, generally with some type of signage that warns people not to attempt entry. However, in some facilities imposing perimeter walls/fencing will not be possible (e.g. an urban office building that is directly adjacent to public sidewalks) or it may be aesthetically unacceptable (e.g. surrounding a shopping center with tall fences topped with razor wire); in this case, the outer security perimeter will be defined as the walls/windows/doors of the structure itself.^[9]

Combination barriers

Steel-based armour, exhibiting plastic deformation as a result of projectile impacts.

Barriers are typically designed to defeat defined threats. This is part of building codes as well as fire codes. Apart from external threats, there are internal threats of fire, smoke migration as well as sabotage. The National Building Code of Canada, as an example, indicates the need to defeat external explosions with the building envelope, where they are possible, such as where large electrical transformers are located close to a building. High-voltage transformer fire barriers can be examples of walls designed to simultaneously defeat fire, ballistics and fragmentation as a result of transformer ruptures, as well as incoming small weapons fire. Similarly, buildings may have internal barriers to defeat weapons as well as fire and heat. An example would be a counter at a police station or embassy, where the public may access a room but talk through security glass to employees in behind. If such a barrier aligns with a fire compartment as part of building code compliance, then multiple threats must be defeated simultaneously, which must be considered in the design.

Plastic deformation as a result of impact can knock loose, tear or squish passive fire protection (PFP) materials, particularly once the PFP materials are stressed. Some PFP materials can at times be very resilient, impact resistant and ductile at ambient. Once stressed by fire, that can change as free water dissipates at 100°C (212°F), and hydrates can be spent near 300°C (572°F), all of which is reached within minutes of a fire. Construction level binders, unlike certain refractories, can also degrade with heat, thus changing the physical properties of many PFP materials across different temperature ranges. None of that is normally a problem. In fact it is part of PFP designs for different reasons. But when combining PFP with ballistics or fragmentation, it is prudent to consider all relevant stresses in designing barriers that must (or may be presumed or advertised to) simultaneously defeat fire, followed by hose stream and impacts that come during a fire event.

Natural surveillance

Another major form of deterrence that can be incorporated into the design of facilities is natural surveillance, whereby architects seek to build spaces that are more open and visible to security personnel and authorized users, so that intruders/attackers are unable to perform unauthorized activity without being seen. An example would be decreasing the amount of dense, tall vegetation in the landscaping so that attackers cannot conceal themselves within it, or placing critical resources in areas where intruders would have to cross over a wide, open space to reach them (making it likely that someone would notice them).

Security lighting

Security lighting is another effective form of deterrence. Intruders are less likely to enter well-lit areas for fear of being seen. Doors, gates, and other entrances, in particular, should be well lit to allow close observation of people entering and exiting. When lighting the grounds of a facility, widely distributed low-intensity lighting is generally superior to small patches of high-intensity lighting, because the latter can have a tendency to create blind spots for security personnel and CCTV cameras. It is important to place lighting in a manner that makes it difficult to tamper with (e.g. suspending lights from tall poles), and to ensure that there is a backup power supply so that security lights will not go out if the electricity is cut off.^[10] The introduction of low-voltage LED-based lighting products has enabled new security capabilities, such as instant-on or strobing, while substantially reducing electrical consumption.^[11]

Intrusion detection and electronic surveillance

Alarm systems and sensors

Alarm systems can be installed to alert security personnel when unauthorized access is attempted. Alarm systems work in tandem with physical barriers, mechanical systems, and security guards, serving to trigger a response when these other forms of security have been breached. They consist of sensors including perimeter sensors, motion sensors, contact sensors, and glass break detectors.^[12]

However, alarms are only useful if there is a prompt response when they are triggered. In the reconnaissance phase prior to an actual attack, some intruders will test the response time of security personnel to a deliberately tripped alarm system. By measuring the length of time it takes for a security team to arrive (if they arrive at all), the attacker can determine if an attack could succeed before authorities arrive to neutralize the threat. Loud audible alarms can also act as a psychological deterrent, by notifying intruders that their presence has been detected.^[13] In some jurisdictions, law enforcement will not respond to alarms from intrusion detection systems unless the activation has been verified by an eyewitness or video.^[14] Policies like this one have been created to combat the 94–99 percent rate of false alarm activation in the United States.^[15]

Video surveillance

Closed-circuit television cameras

Surveillance cameras can be a deterrent^[16] when placed in highly visible locations and are useful for incident assessment and historical analysis. For example, if alarms are being generated and there is a camera in place, security personnel assess the situation via the camera feed. In instances when an attack has already occurred and a camera is in place at the point of attack, the recorded video can be reviewed. Although the term closed-circuit television (CCTV) is common, it is quickly becoming outdated as more video systems lose the closed circuit for signal transmission and are instead transmitting on IP camera networks.

Video monitoring does not necessarily guarantee a human response. A human must be monitoring the situation in real time in order to respond in a timely manner; otherwise, video monitoring is simply a means to gather evidence for later analysis. However, technological advances like video analytics are reducing the amount of work required for video monitoring as security personnel can be automatically notified of potential security events.^[17][18][19]

Access control

Access control methods are used to monitor and control traffic through specific access points and areas of the secure facility. This is done using a variety of systems including CCTV surveillance, identification cards, security guards, biometric readers, and electronic/mechanical control systems such as locks, doors, turnstiles and gates.^[20][21][22]

Mechanical access control systems

A drop arm optical turnstile

An electronic access control system, controlling entry through a door.

Mechanical access control systems include turnstiles, gates, doors, and locks. Key control of the locks becomes a problem with large user populations and any user turnover. Keys quickly become unmanageable, often forcing the adoption of electronic access control.

Electronic access control systems

Electronic access control manages large user populations, controlling for user life cycles times, dates, and individual access points. For example, a user's access rights could allow access from 0700h to 1900h Monday through Friday and expire in 90 days. These access control systems are often interfaced with turnstiles for entry control in buildings to prevent unauthorized access. The use of turnstiles also reduces the need for additional security personnel to monitor each individual entering the building allowing faster throughput.

An additional sub-layer of mechanical/electronic access control protection is reached by integrating a key management system to manage the possession and usage of mechanical keys to locks or property within a building or campus.

Identification systems and access policies

Another form of access control (procedural) includes the use of policies, processes and procedures to manage the ingress into the restricted area. An example of this is the deployment of security personnel conducting checks for authorized entry at predetermined points of entry. This form of access control is usually supplemented by the earlier forms of access control (i.e. mechanical and electronic access control), or simple devices such as physical passes.

Security personnel

Private factory guard

Security personnel play a central role in all layers of security. All of the technological systems that are employed to enhance physical security are useless without a security force that is trained in their use and maintenance, and which knows how to properly respond to breaches in security. Security personnel perform many functions: patrolling facilities, administering electronic access control, responding to alarms, and monitoring and analyzing video footage.^[23]

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Natural surveillance

Natural surveillance

Natural surveillance is a term used in Crime Prevention Through Environmental Design (CPTED) models for crime prevention. These models rely on the ability to influence offender decisions preceding criminal acts. Research into criminal behavior demonstrates that the decision to offend or not to offend is more influenced by cues to the perceived risk of being caught than by cues to reward or ease of entry. Consistent with this research CPTED-based strategies emphasize enhancing the perceived risk of detection and apprehension.

Crime prevention through environmental design

Crime prevention through environmental design

Crime prevention through environmental design (CPTED) is an agenda for manipulating the built environment to create safer neighborhoods.

Fence

Fence

A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or netting. A fence differs from a wall in not having a solid foundation along its whole length.

Plasticity (physics)

Plasticity (physics)

In physics and materials science, plasticity is the ability of a solid material to undergo permanent deformation, a non-reversible change of shape in response to applied forces. For example, a solid piece of metal being bent or pounded into a new shape displays plasticity as permanent changes occur within the material itself. In engineering, the transition from elastic behavior to plastic behavior is known as yielding.

Projectile

Projectile

A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in warfare and sports.

Impact (mechanics)

Impact (mechanics)

In mechanics, an impact is a high force or shock applied over a short time period when two or more bodies collide. Such a force or acceleration usually has a greater effect than a lower force applied over a proportionally longer period. The effect depends critically on the relative velocity of the bodies to one another.

Building code

Building code

A building code is a set of rules that specify the standards for constructed objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permission, usually from a local council. The main purpose of building codes is to protect public health, safety and general welfare as they relate to the construction and occupancy of buildings and structures. The building code becomes law of a particular jurisdiction when formally enacted by the appropriate governmental or private authority.

Fire

Fire

Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. At a certain point in the combustion reaction, called the ignition point, flames are produced. The flame is the visible portion of the fire. Flames consist primarily of carbon dioxide, water vapor, oxygen and nitrogen. If hot enough, the gases may become ionized to produce plasma. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's intensity will be different.

Building envelope

Building envelope

A building envelope is the physical separator between the conditioned and unconditioned environment of a building including the resistance to air, water, heat, light, and noise transfer.

High-voltage transformer fire barriers

High-voltage transformer fire barriers

High-voltage transformer fire barriers, or transformer firewalls, transformer ballistic firewalls, transformer blast walls, are outdoor countermeasures against cascading failures in a national electric grid. The purpose of these barriers, like common fire barriers in building construction, is compartmentalisation of transformer fires, and compartmentalisation of transformer and bushing explosions―in which the fuel source of both fires and explosions is the transformer oil. Without compartmentalisation, one ruptured transformer could start its neighbouring transformer on fire and thus create a domino effect that would affect the surrounding electric grid, particularly during peak times.

Passive fire protection

Passive fire protection

Passive fire protection (PFP) is components or systems of a building or structure that slows or impedes the spread of the effects of fire or smoke without system activation, and usually without movement. Examples of passive systems include floor-ceilings and roofs, fire doors, windows, and wall assemblies, fire-resistant coatings, and other fire and smoke control assemblies. Passive fire protection systems can include active components such as fire dampers.

Landscaping

Landscaping

Landscaping refers to any activity that modifies the visible features of an area of land, including the following:Living elements, such as flora or fauna; or what is commonly called gardening, the art and craft of growing plants with a goal of creating a beauty within the landscape. Natural abiotic elements, such as landforms, terrain shape and elevation, or bodies of water. Abstract elements, such as the weather and lighting conditions.