In response to a
heightened public awareness about terrorism, biohazards and
other crimes since Sept. 11, building owners, in consultation
with design professionals, are seriously considering and often
providing more security for real and potential threats. They
do this through design, technology and operation.
DECORATION Instead of bollards around this pedestrian
plaza, the designer integrated decorative yet protective
obelisks into the Stevens Institute of Technology building
in Hoboken, N.J., across the Hudson River from Manhattan.
(Rendering courtesy of ©ECOPLAN)
Security design extends well beyond
the front door and the property line of a facility, as many
potential threats can cover entire neighborhoods and, in the
worst possible case, could involve a city. From unsecured
manhole covers and underground water mains to grade-level
air intakes and unauthorized loading dock vehicles, secure-building
design anticipates potential loss and damage by protecting
the site perimeter, building envelope, people and property.
Achieving an appropriate balance
between the need for security, and the privileges that have
accompanied relatively open access in society has been widely
debated among design professionals and public officials even
before the 1995 bombing of the Alfred P. Murrah Building in
Oklahoma City. After the Sept. 11 terrorist attacks, acceptable
levels of risk have been reevaluated, especially in New York
City and Washington, D.C., where previously unimaginable security
measures have become the norm.
As a result of Sept. 11, things
previously not considered are getting scrutinized. For example,
many institutions have removed "sensitive" material
from their Websites to prevent it from being accessed and
misused. In other cases, architects and engineers are utilizing
tried-and-true methods for securing buildings in places never
SITE PLANNING 101
Building setbacks, or standoff
distances, create protective building perimeters by restricting
vehicular access. Distance between an explosion and its target
allows the strength of the blast to be dispersed. Standoff
distances vary by facility, location, risk and threat. They
may be reduced in some situations if the site perimeter can
be secured in other ways. Clear zones, free of traffic, are
also desirable to optimize surveillance capability. Typically,
a site analysis and threat assessment will determine how to
maximize standoff distances. In suburban areas, 100 ft is
considered a desirable standoff distance, although this is
often unrealistic in urban settings. The standoff zone can
also be combined with other devices such as bollards, plaza
setbacks, landscaping, trees and boulders to restrict vehicular
HEAVEN For best protection, lobby and its structural
and air systems should be independent of other building
systems. (Drawing courtesy of ©RM Kliment & Frances
and small all-terrain vehicles can deliver explosives, but
rock terracing or concrete retaining walls can be effective
deterrents," says David Dixon, an architect with Goody,
Clancy & Associates, Boston. "Hardened street furniture,
such as benches, lights and large trees, can protect building
perimeters while potentially reducing the need for deep setbacks."
Trees can improve protection by obscuring assets and people,
but they also screen perpetrators from view. Cameras, for
instance, can be discretely located in landscaping and are
not incompatible with trees. "We see many creative security
design opportunities for innovative public art, sculpture,
security screens and vehicular barriers," says Frances
Halsband, a partner at R. M. Kliment & Frances Halsband
Architects, New York City.
Perimeter fencing is assessed as anti-climb and "anti-ram,"
depending on the nature of the threats, says Halsband, who
advises the U.S. State Dept. and the Federal Reserve Bank
on security issues. "We must be able to determine if
a 10-ft fence will stop a high-speed vehicle," she says.
Providing a secure appearance can cause attackers to look
for an easier target. "Locking manhole covers and monitoring
tunnels and areaways regularly will protect exterior utilities,
which are crucial when communications systems are among protected
assets," says Denis I. Goeser, associate and senior project
manager, Leo A Daly Co., Omaha. "With many clients dependent
on computers and data to remain operational, protecting these
systems, and redundant critical utilities, is essential."
After the Sept. 11 attacks, Stevens Institute of Technology,
across the Hudson River from Manhattan in Hoboken, N.J., integrated
site planning, design, technology and operational measures
into its new Technology Management Building, says Martin G.
Santini, president of Ecoplan, Englewood Cliffs, N.J. Santini
added protective obelisks that limited access to all but emergency
vehicles, as well as a street setback. He also enhanced the
visibility of adjacent pedestrian paths, installed an entry
card access system, and added a full-time lobby guard position.
All building penetrations are possible points for security
breaches. Urban high-rises lacking standoff distances, and
any other high-occupancy buildings vulnerable to threats,
pose unique design challenges.
Protecting building services is a big problem. As a general
rule, life safety services, such as gas, fuel, power and water
supplies, should be remote from all high-risk zones or encased
in blast-resistant coverings to maintain service.
Electrical transformers are also vulnerable. Sidewalk-mounted
transformers may be damaged by vehicles, disrupting service.
These transformers can be located inside buildings, eliminating
the possibility that they will be accessed by those who are
unauthorized. However, loss of rentable tenant space and associated
revenue may not appeal to building owners, says Andy Hlushko,
senior vice president of Flack + Kurtz, a New York City-based
Alternate energy sources may
be considered. In areas where steam and gas are available,
owners might consider chillers that can be powered by different
energy sources, although more space is also required. If one
source of power is lost, a second type may be substituted.
Most landlords prefer smaller chillers and mechanical rooms
to maximize rentable area. But these considerations must be
balanced against potential threats and risks, not to mention
construction costs and life-cycle operating costs that also
vary by client and location. There also may be situations
where backup emergency generators should be considered. These
also should be located some distance from each other.
Security of air intake vents is
important, especially for high-rises and large sports facilities.
For high-rise construction, air intakes located 50 to 60 ft
above grade effectively prevent hazardous materials released
at ground level from entering heating, ventilating and air-conditioning
systems. A 50-story building with all outside air coming in
from the top of the building will also safely disperse biochemical
contaminants released at grade. Placing rooftop air intakes
away from the roof edge, and concealing them, if possible,
will also make it harder for would-be terrorists to contaminate
building air supplies.
Where security is high, designers
should plan to provide redundant standpipes for firefighting.
These should not be adjacent to each other. It may also be
necessary to build two separate fire pump rooms and redundant
sprinkler systems. Owners must weigh the costs of redundancy
against the likelihood that a single fire suppression system
might be destroyed.
In certain buildings, redundant
fire alarm systems may be appropriate and well worth the cost,
say designers. An international mixed-use development skyscraper
includes two duplicate fire command centers at remote locations,
and a code-required firefighters' elevator, says Hlushko.
Both the main and satellite centers are fully equipped with
all components tied to a common system. Fire command centers
should be staffed around the clock and located in highly visible
areas, such as lobbies, to provide additional security layers,
he says. Fire alarm devices, such as data-gathering panels
located every third floor, ensure amplification and power
supplies are maintained.
Some buildings present users with
such complex circulation patterns that in an emergency, even
those who use them regularly, may have trouble finding their
way out. Graphics that aid navigation are often an important
addition to exit signage required by code. Exit stairs should
not end in the building lobby because smoke, blast or biochemical
hazards may be present in an attack.
Maintaining fire alarm and public
address systems, with built-in testing and redundancy, is
critical, say experts. Use of multiple speaker currents ensures
that coverage remains if a circuit is lost.
Closed-circuit television is generally
one element of a security plan. Videos are helpful during
investigations, provided they have been stored. With digital
cameras gaining in popularity, hardening of digital video
equipment storage rooms with fireproof materials is becoming
Some international fire codes,
especially in Britain, London, Hong Kong, Malaysia and Canada,
call for separate elevators for firefighters. These consist
of two small, dedicated high-speed elevators per floor, rising
the full height of the building. Sized for three or four firefighters
each, the elevators exit into pressurized vestibules adjacent
to the fire stair enclosure containing hose rack and communication
equipment. U.S. fire professionals have a different philosophy
concerning these special elevators, says Carl Galioto, partner
in charge of the technical group in the New York City office
of architect-engineer Skidmore Owings & Merrill.
The New York City Fire Dept.,
for example, says that with a power loss, elevators and fire
alarm system calls to the street are unreliable, and thus
will not approve a firefighter's elevator code provision.
However, service elevators in high-rises may be designated
for a similar function. These elevators should ideally be
protected by a pressurized vestibule from the elevator lobby
or direct access to the stair from the elevator lobby if a
vestibule is not feasible.
Ongoing security R&D
will continue to improve communications, surveillance, engineering
systems and building materials technologies. Curtains that
can prevent flying glass shards from injuring people, and
new sensors for detecting biohazards activity are among the
Security specialists have
put forth several recommendations for buildings with symbolic
value or tenants who may attract terrorists. Naturally, adoption
of these concepts depends upon a determination of what the
client or building owner deems as "acceptable risk."
Lobby security is getting lots
of attention. The area between the front door and screening
equipment, similar to metal dectectors used by airports, is
at risk. Security is left in the hands of lobby guards. The
lobby should be an isolated zone, hardened with reinforced
walls to protect adjoining areas from blast.
HVAC systems should be designed
to ensure that smoke doesn't migrate from the lobby to elevator
shafts and the rest of the building. Dedicated lobby HVAC
systems and separate supply and return air systems, to isolate
the public space in terms of air circulation from the rest
of the building, would minimize certain risks posed by biological
and chemical hazards let loose in lobbies.
are reviewing lobby security standards so they can attract
government tenants for commercial buildings and private corporate
tenants seeking to meet government standards," says Halsband.
Lobbies require a minimum of 600 sq ft for circulation, equipment
and screening, she adds.
Building a new 600-sq-ft lobby
addition is an alternative for older buildings with limited
interior space. The new structure can be a welcoming pavilion,
providing a secure entry to a hardened facility beyond. This
design concept is appropriate for embassies and international
buildings. It was used at the U.S. Mission to the United Nations
in Manhattan, designed by Gwathmey Siegel & Associates,
New York City.
The new tower includes a "sacrificial
facade," consisting of an exterior wall, vertical air
pocket behind it and another structural wall inside. The facade
is designed to absorb blast impact and contain damage. It
is a first line of defense for the tower's structural integrity.
Loading docks are higher
risk areas than the front entrance because they provide an
easier entry opportunity for truck bombs that can contain
greater amounts of explosives. For those concerned about attacks,
loading docks should be hardenedtheir walls, floors
and framing reinforced. And, they should have good ventilation
in case of a blast. Transformer vaults, electrical service,
emergency power lines and fuel oil pipes, as well as critical
life safety systems such as fire command and emergency systems,
should not be located below or adjacent to loading docks.
Mail rooms and receiving areas
in high-risk buildings should be located off the street and
away from loading docks, with blast hardening and dedicated
ventilation. Additionally, mail rooms should be segregated,
not grouped with other back-of-the-house functions. Separate
buildings for mail rooms, receiving and loading docks, especially
in high- security zones, are another increasingly popular
option. However, the cost of these measures can be high.
For high-risk buildings, basement
parking should be restricted to occupants with identification.
Hardening structure against blasts and emergency ventilation
is also prudent.
It is encumbent upon design
professionals and those who own and develop buildings to remain
alert to the vulnerabilities of the built environment, and
continue to consider solutions for protecting public health,
safety and welfare of the public.
Building For A Secure Future