Crime
Prevention Through Environmental Design (CPTED)

Crime Prevention Through Environmental Design, or CPTED (pronounced sep-ted), is a
crime prevention philosophy based on the theory that 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.
The best time to apply this philosophy is in the design phase, before a building or
neighborhood is built. You can also successfully apply it later, but retrofitting an
existing environment can sometimes be costly.
The use of CPTED will reduce crime and fear by reducing criminal opportunity and
fostering positive social interaction among legitimate users of space. A legitimate user
means one who is using a space for its intended purpose. The emphasis is on prevention
rather than apprehension and punishment.

There are three basic and overlapping principles in the CPTED concept. In order to get
a better understanding of the concept, let us consider these:
Natural Surveillance:
We need to create environments where there is plenty of opportunity for people engaged in
their normal behavior to observe the space around them.
By designing the placement of physical features, activities and people in such a way to
maximize visibility, natural surveillance occurs.
Natural Access Control:
Most criminal intruders will try to find a way into an area where they will not be easily
observed. Limiting access and increasing natural surveillance keeps them out altogether or
marks them as an intruder.
By selectively placing entrances and exits, fencing, lighting and landscape to control
the flow of or limit access, natural access control occurs.
Natural Territorial Reinforcement:
An environment designed to clearly delineate private space does two things. First, it
creates a sense of ownership. Owners have a vested interest and are more likely to
challenge intruders or report them to the police. Second, the sense of owned space creates
an environment where "strangers" or "intruders" stand out and are more
easily identified.
By using buildings, fences, pavement, signs, lighting and landscape to express owners
and define public, semi-public and private space, natural territorial reinforcement
occurs.
Why the emphasis on "Natural?"
Historically, the emphasis has been on the target hardening approach to crime prevention.
Relying on mechanical (locks, security systems, alarms, monitoring equipment, etc.) and
organized (security patrols, law enforcement, etc.) crime prevention strategies means to
make the target harder to get into and can create a fortress effect and "feel"
unsafe. This traditional approach tends to overlook the opportunity for natural access
control and surveillance. By natural, reference is made to the crime prevention by-product
that comes from normal and routine use of an environment.
The CPTED theory advocates that all possibilities for natural crime prevention be
exhausted, prior to the involvement of the mechanical and organized strategies. The CPTED
approach is much more user friendly and customer service oriented than the traditional
target hardening approach.
Example:
A multiple story office building is designed with a large lobby with elevators, a
directory and is expected to be "self serve." Over time, crimes occur in the
lobby area; purse snatches, an assault or two, criminal damage, etc. The owner of the
building installs CCTV to monitor the situation. Eventually guards are employed to monitor
the CCTV, and further down the road, to watch people come and go. By now, people do not
feel comfortable coming here. They feel that it is unsafe, they are being watched on video
cameras, and NOW things are so bad that they have to have a security guard in the lobby
all the time.
A better approach, the CPTED approach, would have been to design in the opportunity
for Natural Surveillance from the beginning. Possibly a receptionist, or a coffee stand.
Put some type of activity into the unassigned space in order to create natural crime
prevention. In addition, the CPTED approach is much more customer service oriented. It
serves the same purpose as the guard, but does not look as harrowing. In fact, it is much
more inviting.

CPTED involves the design of the physical space in the context of the bona fide user of
the space, the normal and expected use of that space, and the predictable behavior of the
bona fide users and offenders. CPTED emphasizes the connection between the functional
objective of space utilization and behavior management. We must differentiate between
designation of the purpose of space, its definition in terms of management and identity,
and it's design as it relates to function and behavior management. By using the
"Three D's" as a guide, space may be evaluated by asking the following types of
questions:
Designation:
- What is the designated purpose of this space?
- For what purpose was it originally intended?
- How well does the space support its current use or its intended use?
- Is there conflict?
Definition:
- How is space defined?
- Is it clear who owns it?
- Where are its borders?
- Are there social or cultural definitions that affect how space is used?
- Are the legal or administrative rules clearly set out and reinforced in policy?
- Are there signs?
- Is there conflict or confusion between purpose and definition?
Design:
- How well does the physical design support the intended function?
- How well does the physical design support the desired or accepted behaviors?
- Does the physical design conflict with or impede the productive use of the space or the
proper functioning of the intended human activity?
- Is there confusion or conflict in the manner in which physical design is intended to
control behavior?
Once these questions have been asked, the information received may be used as a means
of guiding decisions about the use of human space. The proper functions have to be matched
with space that can support them. The design has to assure that the intended activity can
function well and it has to directly support the control of behavior.

Following are a few examples of CPTED strategies in action. In each there is a mixture
of the three CPTED concept keys that is appropriate to the setting and to the security or
crime problems. Some of the examples were created in the direct application of
CPTED.
Others were borrowed from real life situations that were observed to be working. The most
basic, common thread is the primary emphasis on naturalness--simply doing things that you
already have to do a little better.
- Provide clear border definition of controlled space
- Provide clearly marked transitional zones that indicate movement from public to
semipublic to private space
- Relocate gathering areas to locations with natural surveillance and access control or to
locations away from the view of would-be offenders
- Place safe activities in unsafe locations to promote natural surveillance of these
activities to increase the perception of safety for normal users and risk for offenders
- Re-designate the use of space to provide natural barriers to conflicting activities
- Improve the scheduling of space to allow for effective use, appropriate "critical
intensity" and temporal definition of accepted behaviors
- Redesign or revamp space to increase the perception or reality of natural surveillance
- Overcome distance and isolation through improved communication and design efficiencies

By including CPTED principles in new construction, from the design stage, we can make
the built environment safer from the start, rather than waiting for crime problems to
develop and depending on law enforcement to handle them after the fact. By reviewing
existing problem areas and applying the CPTED principles, those problems can be turned
around.
The goal of using the CPTED philosophy is to design and build safer, more productive
and user friendly environments, reducing costs and liability and ultimately, the
improvement in the quality of life. There are no hard and fast rules in CPTED. This
is not good and that bad. CPTED is about sharing ideas and asking questions.
For more information and/or to schedule a security assessment
for your business, call 480-644-2300, option 5, to be referred to the crime
prevention officer for your area.
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