Harris Crime Prevention Services (Harris) applies the following definitions and explanations to the coined terms Crime Prevention Through Environmental Design (CPTED) and Crime Prevention Through Environmental Management (CPTEM). Both initiatives encourage built form ‘welcoming and safe place’.
CPTED’s theoretical platform and principles were suggested by American architect and city planner Oscar Newman in the 1970s, engaging architecture and engineering to re-focus, re-emphasise and/or re-package aspects of good urban design to achieve crime prevention objectives. CPTED is also referred to as ‘safer-by-design’, ‘designing-out-crime’ or ‘security design’. Harris adapts five CPTED principles informing urban design–and-construct briefs:
– CPTED Principle 1 Territorial Definition
– CPTED Principle 2 Access Control
– CPTED Principle 3 Natural Surveillance
– CPTED Principle 4 Activity Support
– CPTED Principle 5 Target Hardening
There are also four spatial zones into which the principles may be applied:
– Zone 1 Public Space – for open and general use; precincts serving a variety of purposes;
– Zone 2 Semi-Public Space – open public precincts but with restricted usage;
– Zone 3 Semi-Private Space – space defined by occupancy and ownership usage;
– Zone 4 Private Space – singly defined purpose usage by specific individuals.
Principle 1 Territorial Definition
This is a delineator of one or more of the above spaces. Territorial design defines form and function of spatial ownership or stewardship emphasising invitational purpose. Perimeters and creative bounded form confirm spatial integrity and cared for legitimacy.
Principle 2 Surveillance
Spatial design maximises surveillance opportunities – formal (active) and informal (passive). Surveillance increases the number, width, depth, height and length of sight lines or fields of vision: the capacity of people and technology to observe movement and activity at distance. All forms of surveillance encourages a security ‘ownership’ or stewardship of territory and promotes informal ‘security intelligence’.
- Natural surveillance encourages casual observation of all users of defined urban space.
- Social surveillance encourages regular (and possibly casual) users of space to more deliberately observe and routinely monitor, challenge or report suspicious pedestrian and vehicle movements through precincts or into buildings.
- Technical surveillance employs visual recognition technology to manage defined spatial access and support human surveillance activity. Video surveillance technology, alarms and access control systems are mainstream crime prevention and crime management tools in urban design.
Principle 3 Access Control
Access control design applies subtle or obvious architecture in support of territorial definition, by clearly indicating directional or destination limits; inviting, restricting or halting access through certainty of movement. Lighting, signage, designated movement corridors, landscaping, fencing, steps and doorways are obvious examples. The principle encourages architects to distinguish access control design within the above four (4) spatial zones.
Principle 4 Activity Support
This involves the use of creative signage, (external) lighting, landscaping and other legible way-finding built form design, to encourage intended patterns of usage while generating activity certainty or liveliness, particularly in public domains.
Principle 5 Target Hardening
Target hardening (strengthening) increases the efforts ‘offenders’ must expend to disrupt legitimate occupancy and activity. Architecture is directed at denying or limiting access to potential criminal targets through more intentional and less subtle design including deliberate physical barriers such as security fencing, gates, locks and alarms. However, the design goal is to avoid ‘fortressing’.
CPTEM is a post-construction platform whose principles complement and support CPTED. It is an occupancy management initiative which maintains embedded (security) design and monitors ‘place’ crime risk to sustain a safe (secure) built form environment. The objective is to sustain a development’s on-going reputation as ‘welcoming and safe place’. The principles are:
– CPTEM Principle 1 Design Maintenance
– CPTEM Principle 2 Systems Management
– CPTEM Principle 3 Risk Mitigation
– CPTEM Principle 4 Incident Responses
– CPTEM Principle 5 Outcome Evaluation
Principle 1 Design Maintenance
Some CPTED initiatives require regular maintenance and/or testing for reliability, obsolescence, redundancy, replacement and re-alignment. Lights, signs, landscaping, security doors, cameras, alarms and locks should receive scheduled maintenance and appraisal to affirm (design) capability and integrity.
Principle 2 Systems Management
This involves the testing and management of security technology systems as they integrate with fire and emergency systems to ensure holistic security and safety operational readiness.
Principle 3 Risk Mitigation
‘Levels’ of security awareness should be developed to engage stakeholders – owners, tenants, security and/or facilities managers and other user-stewards of retail, residential, recreational, commercial, health, educational, industrial and mixed use premises. Security and/or facilities managers should establish formal security policies and procedures. They should also conduct regular ‘desk top’ risk assessments to build and manage a ‘risk-change’ and risk mitigation picture.
Principle 4 Incident Responses
Knowing how to identify and respond to anti-social and criminal incidents is critical. Security and/or facilities managers should develop and ‘rehearse’ responses covering the most common major or minor categories. Incident recording and reporting should be (i) factual, (ii) relevant, (iii) accurate, (iv) clear, and (v) complete.
Principle 5 Outcome Evaluation
Implementation of CPTEM and CPTED requires on-going regular evaluation; critical to ‘test’ the relevance, cost-effectiveness and value (real and perceived) of both initiatives with a view to modelling, replicating and/or improving future security design and security management outcomes.
We believe that CPTED and CPTEM principles are interdependently linked. Often they are neither applied nor linked. Both principle sets should be intentional considerations, integrated into concept, master planning, design-and-construct briefs, and ultimately, into (safe) occupancy management objectives.
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