Typical upper-level floor plan, World Trade Center tower
Potential conflict between freedom and security?
Balancing security and openness in public buildings.
Daniel Patrick Moynihan (1999): "Architecture is inescapably a political art, and it reports faithfully for ages what the political values of a particular age were. Surely ours must be openness and fearlessness in the face of those who hide in the darkness. Precaution, yes. Sequester, no. There is a risk to such a conversation. Call for more openness, and the next day there may be a new atrocity. But more is at stake than personal reputation. The reputation of democratic government is at stake."
not Benjamin Franklin on democracy (misattributed): "Democracy is two wolves and a lamb voting on what to have for lunch."
Benjamin Franklin, circa 1775: "They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety."
Jeremy Bentham, circa 1791: Panopticon—humane reform or insidious form of surveillance:
"In 1975 Foucault used the panopticon as metaphor for the modern disciplinary society in Discipline and Punish. He argued that the disciplinary society had emerged in the 18th century and that discipline are techniques for assuring the ordering of human complexities, with the ultimate aim of docility and utility in the system.[30] Foucault first came across the panopticon architecture when he studied the origins of clinical medicine and hospital architecture in the second half of the 18th century. He argued that discipline had replaced the pre-modern society of kings, and that the panopticon should not be understood as a building, but as a mechanism of power and a diagram of political technology." (Wikipedia)
Building security
Identify threats and weaknesses (vulnerabilities)
Terrorism
"Few things better illustrate the utter meaninglessness of the word Terrorism than applying it to a citizen of an invaded country for fighting back against the invading army and aiming at purely military targets (this is far from the first time that Iraqis and others who were accused of fighting back against the invading U.S. military have been formally deemed to be Terrorists for having done so). To the extent the word means anything operationally, it is: he who effectively opposes the will of the U.S. and its allies." Glenn Greenwald
Jane Jacobs, The Death and Life of Great American Cities (1961)
Idealized safe, mixed-use neighborhoods based on informal visual surveillance of streets
Oscar Newman, Defensible space (1972)
Territoriality — the establishment of a sense of spatial ownership
Natural surveillance — the link between an area's physical characteristics and the residents' ability to see what is happening
Eyes on the street: Members of the Japanese performance group 'Medaman-Medaman' wearing large eyeballs, perform on a street in Tokyo. Jane Jacob's typical West Village (NYC) street (right).
]Image — the capacity of the physical design to impart a sense of security
]Milieu — other features that may affect security, such as proximity to a police substation or busy commercial area [from Wikipedia]
Now known as Crime Prevention Through Environmental Design (CPTED), whose basic principles are:
Natural access control — create perception of risk to those who might otherwise be tempted to enter
Natural surveillance
Territorial reinforcement — building users feel sense of ownership; definitions of controlled (private or semi-private) space
Harden targets
Discussion of Newman's and Jacob's ideas (optional): "Secured by Design" - NBS TV [click on "United Kingdom/Global" link]
Relationship of abstract notions of "territoriality" to racism and segregation/redlining, e.g., in the shooting of Trayvon Martin in 2012. "On the night of February 26, 2012, in Sanford, Florida, United States, George Zimmerman fatally shot Trayvon Martin, a 17-year-old African American high school student. Zimmerman, a 28-year-old mixed-race Hispanic man, was the neighborhood watch coordinator for the gated community where Martin was temporarily living and where the shooting took place." (Emphasis added.)
This critique is explicit in this excerpt from Ta-Nehisi Coates, Between the World and Me, in which he discusses his visit to Jane Jacobs's West Village: "They [white folks] were utterly fearless. I did not understand it until I looked out on the street. That was where I saw white parents pushing double-wide strollers down gentrifying Harlem boulevards in T-shirts and jogging shorts. Or I saw them in conversation with each other, mother and father, while their sons commanded entire sidewalks with their tricycles. The galaxy belonged to them, and as terror was communicated to our children, I saw mastery communicated to theirs.
And so when I remember pushing you in your stroller to other parts of the city, the West Village for instance, almost instinctively believing that you should see more, I remember feeling ill at ease, like I had borrowed someone else's heirloom, like I was traveling under an assumed name." [emphasis added, Spiegel & Grau, New York (2015), pp. 89-90]
Crime (nonviolent)
Espionage
Theft of intellectual (or real) property
Need control of access, both internally and externally
Natural disasters
Fire, earthquake, high winds/rains, flooding
Protect
Buildings
People
Things inside buildings (assets)
Commercial/industrial/financial operations
Three concepts
1. Natural disasters and prior acts of terrorism should be examined and learned from: building codes are updated as a result of such new knowledge. See for example, NIST's World Trade Center Disaster Study
Amazingly, the World Trade Center Report was not available at its usual link in Oct. 2013. Instead, this window appeared:
So I made a new link to my personal copy...
2. After analyzing risks for a particular site, include design, technology, and building operations in an integrated manner.
3. Security should be transparent: this use of transparent is the opposite of how it is often used to denote operations that are visible to the public. Here, the intention is for security measures to be largely invisible. Contrasts large concrete barriers in front of buildings with other devices that cannot be seen.
"Jersey barriers," bollards, and planters for security
The White House fence is a classic example of a security device (barrier) with "aesthetic/historic" complications. See this NY Times discussion: "Secret Service officials acknowledge that they cannot make the fence foolproof; that would require an aesthetically unacceptable and politically incorrect barrier. Prison or Soviet-style design is out, and so is anything that could hurt visitors, like sharp edges or protuberances. Instead, the goal is to deter climbers or at least delay them so that officers and attack dogs have a few more seconds to apprehend them."
Barrier positions as of March 27, 2015 (NY Times image)
Secret Service officers watched tourists at the White House last week. (Credit: Gabriella Demczuk for The New York Times)
Lessons learned
WTC 1993 bombing - truck bomb in underground parking; 150-foot-wide hole, 5 stories deep, 1000+ injured, 6 killed, two sewer lines and air conditioning water lines ruptured (2 million gallons of water and sewage pumped out), biological hazards including raw sewage, asbestos and mineral wool, acid and gasoline (from vehicles), fires, falling concrete; destruction of emergency generator. Took 50,000 people 3-4 hours to evacuate.
Aftermath of 1993 WTC bombing
More on bomb blasts:
Two issues: high-speed objects (projectiles) and increased pressure (overpressure)
Glass shards are major hazard (projectile)
Overpressure is the atmospheric result of chemical change immediately after detonation of bomb causing a heat wave (supersonic gas expansion)
Seismic effect results as blast wave is transferred into the ground
Immediate heat effect of blast wave is limited (though it can trigger combustion near the blast site)
Of more consequence is the wall of compressed air constituting the blast wave that can travel over 700 mph, wrapping around buildings and potentially causing collapse.
A second blast wave of almost equal magnitude follows the first, but in the reverse direction (as air is sucked back into the original space vacated by air moving outwards.
Humans can survive only a limited amount of overpressure (30 - 40 psi). A large car trunk with a 500 lb charge at 30 ft can cause 367 psi of overpressure; box trucks with 5,000 lb charge at 100 ft can cause 100 psi of overpressure.
Lessons: do not locate public underground parking next to buildings, or gas connections, or emergency generators. Vehicular checkpoints established. Consider redundant systems.
1996 Khobar Towers bombing (US base in Saudi Arabia): Install window security film combined with laminated glass to mitigate effects of blast (for retrofitted windows).
1996 bombing of U.S. portion of the Khobar Towers housing complex in Dhahran, Saudi Arabia
1995 Oklahoma City bombing:
1995 bombing of Alfred P. Murrah Federal Building, Oklahoma City
Response included architecture, engineering, and site design elements. Vehicular circulation and access should be controlled (standoff distances, i.e., building setbacks in relationship to potential truck bombs), increased blast resistance of building exteriors, including glazing design to minimize shards of flying glass, avoidance of "progressive" structural collapse.
Progressive collapse of a portion of a building, from Demkin, p.103
Stadium security: check points ("All items allowed into the stadium are subject to search and must fit within the box provided.")
Stadiums are potential targets. Security measures involve screening and control of people and objects, perimeter site access, vehicle circulation, delivery screening (and prohibition on days of events), use of metal detectors at points of screening, placing underground utilities away from entries, loading docks, etc. to prevent damage to such systems in the event of an explosion.
Tall buildings
Egress from tall buildings: Case study is the rebuilt "Seven WTC" which contains the following advanced safety measures:
Structural redundancy to prevent progressive collapse.
Protect egress stairs and other "core" functions with reinforced concrete walls (rather than fire-rated gypsum board).
Use heavier (medium-density) fire-proofing materials on steel structural members.
Design each floor with a central, fire-resistance-rated corridor.
Make the exit stairs wider.
Interconnect the exit stairs.
Provide photoluminescent exit markings and low-level battery-powered exit lights.
Seven World Trade Center egress stairs within concrete core
Additional recommendations of the NYC Task Force on Building Code:
No more open-web bar trusses (commercial high-rise buildings)
Composite truss system used at the World Trade Center
More and wider stairs.
No scissors stairs in high-rise commercial buildings with floor plates of 10,000 sq.ft. or more (e.g., 100 x 100 ft.)
Scissors stairs: plan and section
Serious inspections to make sure fireproofing is intact, especially after building renovations.
Gaps in sprayed-on fireproofing (image found here)
Retrofit (i.e., no more grandfathering) all commercial buildings higher than 100 ft with sprinkler systems.
More advanced fire dept. emergency response communication systems in high rise buildings.
Air intakes should be minimum 20 ft. above grade and away from exhaust discharges and loading docks. [note that GSA requires 40 feet above grade]
Courthouses
Special "symbolic" building.
Separate circulation systems and separate entires.
Courthouse circulation systems (interpretation by J. Ochshorn): Gordon R. Hall Courthouse, MHTN Architects
Identify various zones (public, private, secure, service) and design separate circulation systems to prevent security breaches.
In the case of federal courthouses, regulations deal with site perimeters, restrictions of vehicular access, setbacks, hardened exteriors, blast-resistant walls and windows; attention to progressive collapse.
Office buildings (Federal)
Federally owned office-type buildings (e.g., Oklahoma City)
Screening, guard posts at entries.
Integrated electronic security systems: include security management, intrusion detection, access control, closed-circuit video, video imaging and ID, communications, intercoms.
Retrofitting historic structures
Documentation (stored off-site).
Create smoke evacuation chambers in tall spaces (rotunda, etc); coordinate with mechanical system design.
Add blast-resistant windows, shades, wall liners (e.g., a proprietary fabric lining under the finished wall surface had been installed at the Pentagon; can reduce fragmentation casualties).
Aesthetics of site barriers
"Artists and designers can intersperse bollards with planters, benches, or trees where cleqrances allow, to deemphasize security and mitigate the repetition of identical elements." (p.1.25 Nadel)
Criteria: withstand blast, allow swift evacuation.
Goals: avoid progressive collapse.
Strategies include
Standoff: setbacks from public streets (distance from potential truck bombs)
Redundancy: structural design that anticipates the loss of various structural members.
Hardening (also energy-absorptive shields): in particular, added protection to means of egress, emergency equipment, emergency systems (including electrical, mechanical, communication, and sprinkler)--> not just gypsum board which protects against fire. For columns (e.g., reinforced concrete columns), avoid "brisance" (crushing or shattering effect of a high explosive on brittle materials such as concrete) can be avoided by using s steel "jacket," or a blast shield, or by increased standoff. Note that at 20 feet between such a column in Oklahoma City and the bomb location, the column pretty much disintegrated.
Mechanical systems
Consider isolating mechanical systems for spaces like loading docks and mailrooms so that airborne contaminants cannot enter the main HVAC system.
Security sensors and strategies
Humans are best, but they cost money. Technology (automated sensors) are less expensive. Can detect heat, or motion, for example.
Clear sightlines for surveillance (see Michel Foucault, Discipline and Punish: The Birth of the Prison; the Panopticon with it's unequal ability to observe)
Fencing (both passive and electronic)
Biometric devices to confim identity.
Video recording.
Security glazing
"For the $50 million renovation to the Zorinsky Federal Building in Omaha, Wausau Window and Wall Systems engineered and fabricated 49,305 square feet of blast-mitigating exterior curtain wall plus an additional 18,970 square feet of interior curtain wall for the building. The exterior utilizes Wausau's SuperWall system and four-sided factory-glazed unitized system, both with 1.25" protective glass." [image and caption from Architectural Record]
Blast resistance, but also hurricane (wind-borne debris) resistance.
Pressurization caused by broken glass in a hurricane and lead to much greater building damage (roofs lifted off; walls damaged).
Blast damage can cause injury and death due to unrestrained flying shards of glass.
Site issues
Site selection: earlier human epochs use natural features like mountains, rivers, canyons to enhance security.
Extension of such natural barriers into man-made security features, walls, moats, fences.
Time element: if initial barriers can slow down an attack, then other forces can be put into place.
GSA security zone recommendations
Image taken from Figure 1-6, Hopper & Droge, p.11 (from National Capital Planning Commission)
Zone 1: Building interior
Zone 2: Building perimeter -- evaluate ability of perimeter to resist blast effects; can perimeter be "hardened"? what are costs?
Zone 3: Building yard (setback) -- Interagency Security Task Force recommends 50 ft, with minimum of 20 ft. Within this zone, numerous site security elements can be designed. These include: entry facilities such as gatehouses, raised planters or terraces to impede vehicular access. bollards, light standards, etc. to make it harder for vehicles to breach the perimeter.
Zone 4: Sidewalk
Zone 5: Curb lane (parking)
Zone 6: Street
Buildings are classified as to threat level A - E, with E-level most likely to be threatened. Specifications are then established for appropriate design based on zone and threat level. For example, for a D-level building, perimeter barriers should be able to handle a 6-ton truck at 50 mph approaching the perimeter barrier.
The goal is to integrate security measures with architectural and site design, so that the spaces do not seem overly oppressive.
See this interview/article by Noam Chomsky for some thoughts on the architecture of secure borders: "The US-Mexican border, like most borders, was established by violence—and its architecture is the architecture of violence."
Image of border architecture based on site security strategies (Photo by Scott Shelter, reproduced from Architecture_MPS)
Per ADA, area of rescue or area of refuge emergency communication systems are required in all multistory structures and newly constructed buildings.
Such systems can be designed to route emergency calls either to an on-site 24/7 control center (if available) or to local emergency responders (e.g., police, fire departments).
Five categories of communications systems in commercial buildings need structured cabling systems. These are:
Disclaimer: Students are responsible for material presented in class, and required material described on course outline. These notes are provided as a tentative outline of material intended to be presented in lectures only; they may not cover all material, and they may contain information not actually presented. Notes may be updated each year, and may or may not apply to non-current versions of course.
first posted Sept. 25, 2012 | last updated: Oct. 1, 2019
2007–2021 J. Ochshorn. All rights reserved. Republishing material on this web site, whether in print or on another web site, in whole or in part, is not permitted without advance permission of the author.