Screen Shot 2014-03-17 at 1.39.39 PMWhat is CPTED?

CPTED is a proactive design philosophy built around a core set of principles that is based on the belief that the proper design and effective use of the built environment can lead to a reduction in the fear and incidence of crime as well as an improvement in the quality of life.

CPTED goes well beyond conventional approaches to safeguarding the environment by exploiting natural forms of surveillance, access control and territorial reinforcement in a deliberate attempt to present a psychological deterrent for the purpose of positively influencing human behaviour as people interact with the environment.  It is through these proven applications of CPTED principles that CPTED and its practitioners earn their well-deserved reputation for manipulating the environment which, by no coincidence, serves as the conceptual thrust for the concept.

Far less appreciated is CPTED’s true emphasis which is directed towards assisting the objective of the human activity and, through this process, lowering our exposure to crime and loss.  It is largely for this reason, that CPTED enjoys its broad appeal and has a significant, yet modest, reputation for promoting good design.

What are its benefits?

CPTED offers a number of benefits including major cost savings when the principles are applied at an early stage in the design process.  For best results, a CPTED space assessment should be undertaken as part of the concept plan.  A space assessment can minimize the potential for conflict and confusion by matching the intended functions with a space that can support it.  It will also offer insights into how well the designated purpose of the space (designation for short) meshes with the intended function and how the definition and design of a space can help to ensure that an intended activity can function well while, at the same time, providing support for the control of the human behaviour.

Potential CPTED benefits include:

  • productive use of space
  • improved function and/or profit
  • reduced exposure to fear, crime, loss and liability
  • partnerships and problem solving
  • improved quality of life, and
  • major cost savings.

What are CPTED’s core principles?

CPTED has three main principles.  They are:

  • natural surveillance,
  • natural access control, and
  • territorial reinforcement.

Screen Shot 2014-03-17 at 1.39.31 PMNatural Surveillance

The concept of natural surveillance was first identified by Oscar Newman as one of four requirements needed for the establishment of Defensible Space.  Natural surveillance is a design strategy that is directed at keeping intruders under observation.  It is based on a simple premise that a person inclined to engage in criminality will be less likely to act on their impulse if he or she can be seen.

Natural surveillance is commonly associated with the establishment of clear sightlines.  While generally a worthwhile goal, the pursuit of clear sightlines must be tempered by a number of considerations including the ability to capitalize and/or generate witness potential and the need to establish and provide for landscaping.

Screen Shot 2014-03-17 at 1.39.22 PMSuccessful natural surveillance applications include:

  • orienting driveways and paths towards natural forms of surveillance such as building entrances and windows
  • increasing visual permeability of vulnerable areas such as building entrances, stairwells, playgrounds etc. through the strategic use of windows, fencing material , landscaping etc.,
  • trimming back overgrown landscaping
  • strategically lighting pathways and other potentially problematic areas where opportunities for natural surveillance exist, and
  • developing uses for the environment that are capable of strategically generating activity.  This can include the establishment of sidewalk patios, seating areas and other amenities.

Natural surveillance can be complemented by mechanical forms of surveillance (closed circuit television) and/or organized forms such as security and police patrols.  Mechanical and organized forms of surveillance should be emphasized where natural forms of surveillance are limited.  This includes parking garages and any place that regularly lacks a critical intensity of people.

Screen Shot 2014-03-17 at 1.39.14 PM

Natural Access Control  

Natural access control is a design concept that is directed at decreasing crime opportunity.  It is based on the simple premise that a person who is confronted with a clearly defined and/or strategically developed boundary, will typically show it some deference by respecting the way it guides and influences their movement as they transition from public through private space.  Natural forms of access control includes fences, low walls, landscaping, gates and any barrier that is natural for the environment including topographical features, sales counters and even distance.  Natural forms of access control are particularly effective when combined with natural surveillance.  The combination of natural forms of surveillance and access control can create a perception of risk in offenders that reduces their desire to step foot on the property or engage in criminal activity.

Successful natural access control applications include:

  • providing clear border definition of controlled space
  • limiting uncontrolled and/or unobserved access onto properties, buildings and private space,
  • adding dense or thorny landscaping as a natural barrier to reinforce fences and discourage unwanted entry
  • using space to provide natural barriers to conflicting activities.

Natural access control can be complemented by mechanical forms of access control such as locks and alarms and/or organized forms such as security and police patrols.  Mechanical and organized forms of access control should be emphasized where natural forms are limited.  This includes compounds, storage areas and any place where that regularly lacks people.

Territorial Reinforcement

Territorial Reinforcement has its’ roots in Oscar Newman’s Defensible Space.  It is a design concept that realizes that physical design can create or extend a sphere of influence so that users develop a sense of proprietorship that is noticeable to the offender.

Territorial reinforcement has been described as an umbrella strategy that encompasses natural surveillance and access control.  Used properly, natural surveillance and access control can help people to develop a sense of ownership about a space regardless of whether or not they own it.  Territoriality often results in challenging behaviour.

Successful territorial reinforcement applications include:

  • creating clearly marked transitional zones as persons move from public to semi-public and private space using paving patterns, symbolic barriers or markers, signs  and other visual cues,
  • providing amenities in communal area that encourages activity and use,
  • avoiding the creation of no-man’s land by ensuring that all space is assigned a clear, and preferably, active purpose,
  • developing visitor reporting procedures for larger scale entities that regularly receive people, and
  • conducting timely maintenance.