Crime Prevention Through Environmental Design (CPTED)
Crime Prevention Through Environmental Design, or CPTED, is a cost-efficient and effective security concept that focuses on the use of space and natural elements to provide a desirable quality of life and safety for authorized occupants while increasing the difficulty for criminal and abnormal activities.
Territoriality refers to the use of physical and psychological elements to define an area. The goal is to increase the occupant’s sense of safety and ownership while easily identifying abnormal behavior or unauthorized entry.
A clean, well-lit area creates an environment in which the intended occupants feel safe and where acceptable behavior is encouraged. For a criminal, however, the opposite is true. In an areas that is well-designed, lit, and easy to observe, an unauthorized person loses the advantage they may have had otherwise. This allows intended users to more easily identify and report illegal activity. The concept of wayfinding uses architectural and landscaping features to clearly direct people where they should go. That way, those that ignore those established boundaries stand out for further investigation.
- Provide a clearly-defined boundary around the grounds, which provides visual clues as to what it public and private property. Examples may include fences, landscaping beds, treelines, etc.
- Ensure entry points are well-established both physically and psychologically. Although secure gates are sometimes required for security purposes, they also establish the facility as one that requires protection. If possible, use landscaping and decorative features to disguise the security features
- Use pavement patterns, vegetation, low walls, landscaping or other features to establish physical and psychological separation of ideas
- Only using signage to reinforce wayfinding when doing so would not reveal the nature of the facility
- Creating a non-transparent barrier (such as a fence or a hedge) surrounding the facility helps to prevent observation from the street. However, it can also create more places for an unauthorized person to hide from those entering the grounds. An opaque barrier should only be employed if sufficient lighting and observation can be assured from within.
Natural surveillance refers to the use of design to support visibility within the grounds and around the buildings.
Good visibility of the entire grounds should be maintained, and only supplemented by surveillance technology. The idea is for authorized individuals to “see and be seen” in order to discourage criminal behavior. This not only increases security, but also the occupant’s perception of safety.
- Ensure all pathways and driveways are within a clear line of site from the building
- Orient parking areas perpendicularly to the buildings to maximize visibility
- Select and maintain plants to keep shrubs and vegetation below three feet and tree canopies higher than seven feet to limit hiding places
- Maintain a clear space of at least three feet on either side of sidewalks
- Use barrier plants (such as those with thorns) in areas where pedestrian traffic is undesirable. For example, under windows.
- Avoid building large, windowless walls which restrict visibility
- Place desks and work spaces where staff has clear lines of sight of walkways, driveways, and parking areas
- Avoid isolated stairwells and block off open areas under stairs
- Place common areas, such as picnic or barbeque areas, in places that allow for natural surveillance of the grounds
Natural Access Control
Natural access control ties the two previous concepts together. It uses layout and design elements to direct people from location to another while reinforcing territoriality and supporting natural surveillance. It increases both the perception of and actual risk to potential offenders.
The goal is to limit the number of authorized access points to the absolute minimum required without negatively affecting operations, and also to guide people through the space along authorized routes.
- Limit pedestrian and vehicle entrances to the grounds to the bare minimum possible. Ensure intended entrances are clearly recognizable and methods are in place to disallow or discourage unauthorized entry points
- Develop clear routes between authorized areas, such as parking areas and entrances
- Use a combination of site features, building design and layout, and pathways to channel pedestrians and vehicles along authorized routes
- Limit the number of building entrances to the minimum amount possible without impeding shelter operations. Ideally, there will be one authorized entrance with other points being reserved for emergency egress points
Shelter personnel need to be able to see up to the perimeter of the grounds at different lighting levels, and to identify the outlines of silhouettes even when exposed for only a short period of time. Lighting alone is not sufficient, and is most effective when it would glare the eyes of intruders while improving the visibility.
Adequate lighting is designed to:
- Allow you to detect, assess and react to threats
- Deter intrusion or illegal behavior
- Increase visibility
- Provide a feeling of safety
- Continuous lighting: lighting that remains on and active during periods of low visibility
- Glare lighting: lighting designed to reduce the visibility of intruders
- Standby lighting: lighting designed to supply adequate illumination in case the normal system fails
- Emergency lighting: lighting designed to allow safe egress in the event of an emergency
- Motion-activated: Lighting activated by movement, generally configured to detect unauthorized access to an area
- Open areas, such as outdoor storage or parking areas, should be illuminated to detect passage through or across
- Lighting sources arranged in such a way as to eliminate shadowed areas where unauthorized persons may hide
- The primary lighting source is usually a public utility, but alternate sources should come on automatically when the primary source fails (i.e., the facility shall prepare for power outages to the greatest extent possible)
- Lighting shall be arranged in such a way as to support CCTV / security camera placement
5. Intrusion Detection Systems
Wherever possible, the facility will use intrusion detection systems (IDS) to detect and alert staff to any unauthorized access. These should be installed in areas that are not under constant visual surveillance, and may include fences, windows, doors, etc
Using signs to indicate that the building is protected by an alarm provides a strong psychological deterrent without drawing undue attention