“CPTED is essentially the prem-
ise that people with malevolent
intent want to be clandestine
and don’t want to be detected or
observed,” explains Sean Ahrens,
Security Market Group Leader
for Affiliated Engineers. “We can
change the built environment
to make them more observable,
thereby creating fear that they’ll
be caught either during the inci-
The layered principles follow
the flow of foot traffic, from des-
ignated paths onto and through
the site to the layout of the build-
ing interior.
“Orient workstations so you
can look out onto the lobby
or parking lot or into the cor-
ridor. Lines of sight allow you
to observe what’s going on in
the common areas,” says Art
Hushen, President and Owner of
the National Institute of Crime
Prevention, a training and con-
sulting company specializing
in CPTED. “That encourages
people to feel responsibility and
ownership: ‘This is my company’
or ‘This is my school, and that
doesn’t look right so I’m going to
notify security.’”
Is your building implementing
CPTED as well as it could be? Try
looking for major red flags first,
such as trees that block lines of
sight or lighting that’s uneven or
inadequate, then explore each of
the principles in greater detail.
Principle 1: Natural
Surveillance
Natural surveillance is characterized by two complementary
goals: minimizing ambush points
and enabling the unobstructed
observation of people with malevolent intent. Landscaping and
lighting mistakes are the two biggest areas of neglect where this
principle is concerned, Hushen
continued
SEA
N
AH
R
ENS
explains, followed by interrup-
tions in lines of sight.
“Natural surveillance is critical,
but when you put a concrete col-
umn right outside the reception
area, no one can see through the
front door,” Hushen adds. “You’ve
got cameras, but no one is going
to watch the same camera for
eight hours straight. If someone
can just glance up and see all
the way out to the parking lot, it
makes their job much easier.”
Ideally, you should be able to
see someone approaching from
a considerable distance without
any visual obstacles getting in the
way, Ahrens says. “A good exam-
ple is those car lots that look like
Las Vegas, where you think ‘How
much money are they spending
on all that power?’ Well, if you
were actually in the parking lot
looking out to the foreground,
you wouldn’t be able to see any-
UNEVEN OR INADEQUATE
LIGHTING makes it tough to
see at night, putting occupants
at risk and offering cover to
potential criminals. Good
lighting is a key component
of all four CPTED principles.
ALCOVES AND UNEVEN
GRADING, such as this bioswale,
are a nightmare for natural
surveillance, as they offer easy
hiding places for thieves or other
criminals. Ideally, you should be
able to see people approaching
from a considerable distance.
