cpted an introduction and conceptual framework
DESCRIPTION
Introducing Arup's view on CPTEDTRANSCRIPT
Chris Tomlinson
Arup Resilience, Security and Risk
October 2011
CPTED – An Introduction and its role in Built Environment Security
Agenda
Definition & Intent
Theoretical Background
Concepts and Language
Good and Bad Practice
Examples
Realities and Criticism of the Approach
Futures and Compatibility
Sources
CPTED Definition
“The proper design and effective use of the built environment that can lead to a reduction in the fear and incidence of crime and an improvement in the quality of life.
The goal of CPTED is to reduce opportunities for crime that may be inherent in the design of structures or in the design of neighbourhoods.”
Crowe 2001
CPTED Intent
The theory of CPTED is based on a simple idea i.e. that crime results partly from the opportunities presented by physical environment.
CPTED is the design or re-design of an environment to reduce crime opportunity and fear of crime through natural, mechanical, and procedural means.
CPTED is best applied with a multi-disciplinary approach that engages planners, designers, architects, landscapers, law enforcement and (ideally) residents/space users.
The Focus is Conventional Crime
CrimeViolence against the personTheft/robberyBurglaryFraudVandalism
Civil DisorderAnti-capitalistSingle issueFixated individualsAnti-brand
NuisanceBeggingRough sleepersSubstance abuseFly posters
Although CPTED techniques do assist in anti-terrorism, but to what degree is hard to measure
Using Realistic Risk-driven Design
Theoretical Background It was first coined as a term by the US criminologist, C. Ray Jeffery in 1971 -
arguing that sociologists had overstated the social causes of crime e.g.: deprivation and other sub-cultural influences; and had neglected biological’ and environmental determinants; other influences include:
- Defensible Space, promoted by the US architect Oscar Newman; a famous critique of American public housing at about the same time as Jeffery’s book. Newman put much of the blame for the high crime rates in public housing “projects” on their lay-out and design. Also influenced by Jane Jacobs and her belief in diversity of street use
- Situational crime prevention, developed by the UK government’s criminological research department in the mid-1970 to 80. Unlike CPTED, and “defensible space”, this approach is not concerned principally with architectural design and the built environment
- Environmental Criminology ‘Broken windows’ theories on decay driving crime and nuisance
Most of the academic research into the relationship between crime and environmental opportunities has been conducted under the rubric of situational crime prevention.
Situational Crime Prevention
But CPTED is not operationlised “situational crime prevention”, which is:
- Target Hardening - reducing criminal opportunities by making the situation or property less vulnerable (car steering locks)
- Target Removal - using cheques instead of cash - Removing the means to commit crime - gun law control- Reducing Pay Off - marking goods- Formal Surveillance - police patrols- Natural Surveillance - building houses to overlook one another- Surveillance by Employers - managers in public housing- Environmental Management - good liaison between football clubs and
police in preventing fan violence.
However, there are design crossovers e.g. Target Hardening, Natural Surveillance and Environmental Management.
Criminal Opportunity
Location, including capable guardianship
Vulnerable Target Motivated offender
“Individual criminal events must be understood as confluences of offenders, victims or criminal targets and laws in a specific settings at particular times and places“. Brantingham and Brantingham, Environmental Criminology (1981)
The Nature of Crime Targets - CRAVED goods
Based on Ron Clarke’s concept of ‘Hot Products’ – those at heightened risk of theft by virtue of being ‘CRAVED’ i.e. having one or more of the following properties:
- Concealable
- Removable
- Available
- Valuable
- Enjoyable
- Disposable
Some Realities on Offending Behaviours CPTED measures (many rely on psychological cues) may not be
that obvious to potential offenders e.g.:- Derelicts- Buccaneers – attention seekers- Situation exploiters – mass and event- Alternate cultures – graffiti artists, skate boarders, PK Traceurs etc
CPTED is undermined by post-offence inaction
Must be risk-based i.e. CPTED applied without a full understanding of the micro, meso and macro-crime patterns is pointless – well at least the micro-crime patterns
Displacement in space, time and target
Fear of crime and recitations of pre-conceived ideas i.e. too much emphasis on ‘broken windows’ as a signal of societal failure
CPTED Principles
Territoriality
Natural Surveillance
Access Control
Target Hardening
Image Maintenance
Activity Support
Good Practice
Planning obligations – e.g. Crime prevention and the assessment of development applications under section 79C of the NSW Environmental Planning and Assessment Act 1979
Architect engagement – the US has reached out to AIA and in the UK police ALO/CPDAs are engaging RIBA audiences
International CPTED Association – US/Canada/Australian/NZ
Designing out Crime Association – UK
Europe – EU programme maturing, but has not researched success
Bad Practice
Overstating CPTED Effectiveness – e.g. CCTV or lighting effectiveness often overplayed
Unhelpful affiliation with design – making the CPTED fit the design and genuinely independent advice could conflict with commercial interests (commoditisation of security advice)
‘Boilerplate’ not always transferrable – ‘Cookbook solutions’
Lack of follow-on assessment of design measure effectiveness – operability and tuning
Failure not admitted to – CPTED failure and context should be recorded it will develop knowledge
Territoriality
Territoriality Explained
Unambiguously define edges between the various types of spaces and uses
Create clarity of purpose and use
Prevent flow-through circulation routes that connect outside (public) spaces
Not be ‘shy’ about making some edges physically impenetrable
Keep the public in public types of spaces and out of the private ones
Lay claim to semi-public spaces by encouraging residents to use them.
Natural Surveillance
Access Control
Image Maintenance
Activity Support
Think Offender and Nuisance in the Space
Does CPTED Work? Cozens found it to be a qualified yes
- CPTED components of surveillance, access control, territorial reinforcement, activity support, image/ management, target hardening all individually contribute to reducing crime & fear in broad range of studies
- CPTED shown to reduce crime and the fear of crime in numerous evaluations and to increase property values and investment in the area
However: - Support for the effectiveness of comprehensive CPTED projects has not
been unequivocally demonstrated - Uncertain precisely how CPTED and its component parts work, where it
works best and how to systematically evaluate its effectiveness (or otherwise) beyond reasonable doubt
- Rigorous testing and evaluation procedure to produce deeper understanding of theoretical basis of CPTED mechanisms
- Uncertain precisely how CPTED and its component parts work, where it works best and how to systematically evaluate its genuine effectiveness
CPTED and Problems It is prone to fashion and drift of meaning, and meaning
different things to different agencies or disciplines
It is ‘in a disciplinary No Man’s Land’:- It is isolated empirically and theoretically from rest of crime prevention,
even situational prevention- Lack of criminological rigour/clarity - Basic concepts need further investigation (e.g. the effects of territoriality
may not be universal- The theory has not been integrated – the four strands (Defensible Space,
CPTED, Situational Crime Prevention, Environmental Criminology) are simply placed side-by-side, requiring the user to fit them all together. This is inappropriate complexity masquerading as simplicity
- Evidence base needs developing on detailed risks of crime addressed by CPTED, causes/ consequences/ interventions
Alternative Practices
Accommodating behaviours that might be acceptable
More space-user CPTED tuning
Landscape manipulations
Second generation CPTED
Think Design-based Solutions
Promote acceptable behaviours and space use
Test solution even as a desk-top multi-disciplinary exercise
Think sustainability, maintainability and aesthetics
Think Fear of Crime“Gradually fear extends its domain in the city, with a preference for open spaces. Rarely does it retreat from conquered ground, and in exchange it takes new ones to add to its domains. It is we who retreat, we who give way, we abandon a space which is left at the mercy of fear. Sometimes we resist, we fight back, we suffer the anxiety rather than lose a space that is ours, though in the end we will give the position up, we will not set foot in that part of the park again after dark, we will avoid those neighbourhoods, we will not walk so carelessly in outlying areas, we will take a taxi instead of the underground after a certain hour”.
Isaac Rosa (2008). El país del miedo
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The Arup Approach
Architects Client/users Developers
Early Engagement (risk-led) by Security Consultants
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We Should use CPTED to: Reduce the probability of crime and nuisance, whilst enhancing
the quality of life through community safety
Use opportunities in planning and design of the built-environment on a range of scales and types of place from individual buildings and interiors to wider landscapes, neighbourhoods & cities
Produce designs that are 'fit for purpose‘, and contextually appropriate in all other respects
Whilst achieving a balance between: the efficiency of avoiding crime problems before construction and the adaptability of tackling them through subsequent
management and maintenance
To compliment our sustainable approach to projects.
Sources – not an exhaustive list
Academic – Clarke, Cozens, Ekblom, Jeffery etc- Theoretical Background to CPTED and Situational Prevention, Ronald V
Clarke, 1989- Crime prevention through environmental design: a review and modern
bibliography Paul M Cozens, 2005.
Government:- US – State CPTED networks- Canada – Province CPTED networks- Australia – State and territory guidance (Victoria, NSW and Western
Australia)- EU – European Crime Prevention Network (EUCPN)- UK – The ACPO Secured by Design scheme
Associations and Conference proceedings – These need to be looked at or listened to only by the hardiest, as often there is critique that may be hard to put in context