Crime Prevention Through Environmental Design or "CPTED" (pronounced sep-ted) is an approach to crime prevention that takes into account the relationship between the physical environment and the users of that environment.
We all recognise when the space we are in sends us a message about safety, "this is a safe place" or danger, "this is an unsafe place". The theory behind CPTED is that the design of a physical environment can produce behavioural effects that will reduce both the incidence and fear of crime. These behavioural effects can be accomplished by reducing the suceptibility of the environment to support criminal behaviour.
There are three basic strategies in CPTED:
- Natural access control
- Natural surveillance
- Territorial reinforcement.
Natural access control
The design concept of access control is directed primarily at decreasing criminal accessibility. Natural access control restricts criminal intrusion, in particular into areas where they will not be easily observed, by:
- Limiting access
- Increasing natural surveillance
Gates, fences, walls, footpaths, landscaping and lighting can be used to:
- Clearly guide the public to and from specific entrances and exits.
- Prevent or discourage public access to or from dark or unmonitored areas.
- Enable intruders to be more easily recognised.
Activity support refers to safety measures that use a specific activity planned for a specific space. It involves locating an activity so individuals engaged in that activity become part of the natural surveillance system. The following examples demonstrate how activity support can operate to increase safety.
- The perception of safety for normal users of a space or building, and the perception of risk for offenders, can be increased by placing safe activities in places that will discourage would-be offenders.
- High-risk activities should be shifted to safer locations to overcome the vulnerability of these activities and to take advantage of natural surveillance within the safe area.
- Gathering areas should be located in areas that provide for natural surveillance and access control or in locations away from the view of would-be offenders
- Space can be scheduled to accommodate the most effective activities and to tolerate the appropriate intensity of particular behaviours.
Proper maintenance of landscaping, lighting treatment and other features can assist in the prevention of crime. For example:
- Maintaining lighting fixtures to prescribed standards.
- Maintaining landscaping prescribed standards.
- Balancing potential conflicts between surveillance and landscaping as groundcover, shrubs and trees mature.
Natural surveillance is a design concept that aims to keep potential offenders and intruders under observation through the creation of environments where there is sufficient opportunity for people engaged in their normal behaviour to observe the space around them. Areas can be designed so they are more easily observed through:
- Design and placement of physical features to maximise visibility. For example, through building orientation, windows, entrances and exits, car parking areas, refuse containers, walkways, guard gates, landscape trees and shrubs, use of walls such as wrought iron or picket fences, signage and other physical obstructions.
- Placement of persons or activities to maximize surveillance possibilities.
- Maintenance of minimum lighting standards to provide for night-time illumination of parking lots, walkways, entrances, exits and related areas.
Territoriality is a design concept that clearly delineates private space from semi-public and public spaces and also creates a sense of ownership. When there is a sense of ownership within a space, strangers and intruders stand out and are more easily identified. This can be achieved through:
- Reinforcing existing natural surveillance and natural access control strategies with additional symbolic or social ones to enhance a feeling of legitimate ownership.
- Designing a space to accommodate long-term and continued use and to fit its intended purpose.
- Using pavement treatments, landscaping, art, signage, screening and fences to define and outline ownership of space.