Crime Prevention through Environmental Design (CPTED) is defined as the proper design and effective use of the built environment to reduce crime, disorder and the fear associated with crime.
The CPTED concept involves more than security standards. It first acknowledges the desired use for a project. Next, it attempts to anticipate misuse based upon area crime problems, unique aspects of the project (i.e. alcohol sales) and community experiences with similar projects. Finally, CPTED seeks to prevent undesired behavior by the elimination or modification of design features that contribute to crime and disorder.
Public safety staff participates in the development advisory review process to ensure that developers follow CPTED principles. Staff reviews development proposals; talks with developers, contractors, architects and engineers in the field; conducts CPTED inspections; and reviews security plans.
Staff considers four key principles during the CPTED review process: natural surveillance, natural access control, territorial reinforcement and maintenance.
Natural Surveillance is a design concept directed primarily at keeping potential criminals and their targets under observation. Applying natural surveillance concepts during planning often reduces the need for more expensive security measures.
Natural Surveillance Examples
- Orient building and windows to provide maximum surveillance of exterior areas.
- Limit the use of window vision restrictors such as potted plants, draperies, signage, landscaping, public art and reflective window treatments.
- Design parking lots to allow a high degree of observation from buildings and streets.
- Plan entryways that are visible to adjacent neighbors or passersby; not secluded alcoves.
- Design interior shelf height in retail and commercial uses to no more than five feet.
- Utilize peepholes and vision panels in management offices and rear doors to provide surveillance and observation.
- Locate benches throughout common use or employee areas to enhance observation and supervision of surrounding areas.
- Place child play areas in maximum observation locations.
Natural Access Control
Natural Access Control is a design strategy directed at decreasing crime by denying access to targets and creating a perception of risk to offenders. It is also used to prevent public access to private areas. CPTED discourages a "fortress mentality" but recognizes that high-value targets require the application of more traditional security measures.
Natural Access Control Examples
- Restrict number of entry/exits for better supervision.
- Use landscape such as low hedges and flowerbeds to identify points of entry and movement on property.
- Use signage and symbolic barriers to direct vehicular and pedestrian traffic.
- Designate boundaries between public, semi-public and private spaces.
- Use reception areas to control the flow of visitors.
- Use illustrated diagrammatic representations in lobby and common areas.
- Use light to guide movement.
- Use security planting to restrict access to private areas.
- Install devices to prohibit general access to unauthorized areas.
- Locate public paths in direct routes to points of entry.
Territorial Reinforcement is the belief that physical design can contribute to a sense of ownership and responsibility for a space. This results in higher actual and perceived levels of risk to potential offenders.
Territorial Reinforcement Examples
- Use thorny or thick plant materials in perimeter landscape areas to discourage cutting through parking areas, trampling vegetation, approaching ground floor windows or climbing fences and walls.
- Use appropriate signage to discourage trespassers, loitering or consumption of alcoholic beverages.
- Use public art, sculpture, flags and banners where allowed.
- Use physical and symbolic barriers.
- Use City crime prevention programs such as Neighborhood Watch, Business Watch and Partners Against Crime along with appropriate signage.
- Modify surfaces to make tagging (graffiti) or skateboarding more difficult.
- Use landscape lighting to mark territory.
Improper maintenance is the enemy of territorial reinforcement and implies "no one cares what happens in this place." Thus, proper design supports maintenance by including graffiti resistant surfaces, vandal-proof lighting and landscaping selected for easy maintenance.