Risk Management Series 

Incremental Protection for 
Existing Commercial Buildings 
fromTerrorist Attack 

Providing Protection to People and Buildings 

FEMA 459 / April 2008 


FEMA


Risk Management Series 

Incremental Protection for Existing Commercial Buildings from Terrorist 
Attack:  Providing Protection to People and Buildings 


Any opinions, findings, conclusions, or recommendations 
expressed in this publication do not necessarily reflect the views of 
FEMA. Additionally, neither FEMA nor any of its employees makes 
any warranty, expressed or implied, or assumes any legal liability 
or responsibility for the accuracy, completeness, or usefulness of 
any information, product, or process included in this publication. 
Users of information from this publication assume all liability 
arising from such use. 

Foreword and Acknowledgements  

Background
The Federal Emergency Management Agency (FEMA) developed 
FEMA 459, Incremental Protection for Existing Commercial Buildings 
from Terrorist Attack, to provide guidance to owners of existing 
commercial buildings and their architects and engineers on security and 
operational enhancements to address vulnerabilities to explosive blasts 
and chemical, biological, and radiological hazards. It also addresses how 
to integrate these enhancements into the ongoing building maintenance 
and capital improvement programs. These enhancements are intended to 
mitigate or eliminate long-term risk to people and property. 

FEMA?s Risk Management Series publications addressing security risks 
are based on two core documents: FEMA 426, Reference Manual to Mitigate 
Potential Terrorist Attacks Against buildings, and FEMA 452, Risk Assessment: 
A How-To Guide to Mitigate Potential Terrorist Attacks Against Buildings. 
FEMA 426 provides guidance to the building science community of 
architects and engineers on reducing physical damage caused by terrorist 
assaults to buildings, related infrastructure, and people. FEMA 452 
outlines methods for identifying the critical assets and functions within 
buildings, determining the potential threats to those assets, and assessing 
the building?s vulnerabilities to those threats. This assessment of risks 
facilitates hazard mitigation decision-making. Specifically, the document 
addresses methods for reducing physical damage to structural and non-
structural components of buildings and related infrastructure and 
reducing resultant casualties during conventional bomb attacks, as well as 
attacks involving chemical, biological, and radiological agents. 

FEMA 459 can be used in conjunction with FEMA 452. This manual 
presents an integrated, incremental rehabilitation approach to 
implementing the outcomes of a risk assessment completed in accordance 
with FEMA 452, Risk Assessment: A How-To Guide to Mitigate Potential 
Terrorist Attacks Against Building. This approach is intended to minimize 
disruption to building operations and control costs for existing commercial 
buildings. 

The integrated incremental approach to risk reduction in buildings was 
initially developed in relation to seismic risk and was first articulated in 
FEMA?s Risk Management Series in the widely disseminated FEMA 395, 
Incremental Seismic Rehabilitation of School Buildings (K 12), published in 
June 2003. In 2004 and 2005, FEMA also published Incremental Seismic 
Rehabilitation manuals (FEMA 396-400) for hospitals, office buildings, 
multifamily apartments, retail buildings, and hotels and motels. 

OBJeCtiVe anD sCOPe 

This manual outlines an approach to incremental security enhancement 
in four types of existing commercial buildings: office buildings, retail 
buildings, multifamily apartment buildings, and hotel and motel 
buildings. It addresses both physical and operational enhancements that 
reduce building vulnerabilities to blasts and chemical, biological, and 
radiological attacks, within the constraints of the existing site conditions 
and building configurations. 

The information contained in this document is: 

. Not mandatory 
. Not applicable to all buildings 
. Not applicable when it interferes with other hazards such as fire 
However, the manual presents incremental approaches that can be 
implemented over time to decrease the vulnerability of buildings to 
terrorist threats. Many of the recommendations can be implemented 
quickly and cost-effectively. 

LiMitatiOns 

This approach to incremental security enhancement applies to 
commercial buildings in urban or semi-urban areas. This approach does 
not apply to exceptionally high-risk iconic buildings of symbolic value. 
Examples of such buildings include the tallest buildings in a city, high 
rise buildings with a distinctive shape recognizable in the city skyline, and 
diplomatic buildings, such as embassies. Security enhancement in this 
class of buildings should be based on detailed engineering analysis and 
design. 

IntenDeD aUDienCe 

This manual addresses the specific needs and practices of commercial 
building owners, and guides building owners and managers through a 
process that will reduce the risks to their buildings from terrorist attacks. 

It is intended for use by both technical and non-technical audiences, 
including: 

. Building Owners 
. Facility Managers 
. Risk Managers 
. Security Consultants 
. Design Professionals 
COntent anD ORganiZatiOn 

This manual provides building owners and their design consultants with 
guidance on developing a program of incremental security enhancements 
that can be implemented over a period of time. 

Chapter 1 provides an overview of integrated incremental rehabilitation 
of buildings, potential terrorist threats to buildings, the mitigation of 
the risks of terrorist attacks, special issues related to security in 
existing 
commercial buildings, a process for integrating incremental mitigation 
into the normal facility management process, and a step-by step 
approach to implementation of an incremental enhancement program. 
It is intended for building owners and their risk managers and facility 
managers. 

Chapter 2 describes the relationship between this manual and FEMA 452 
and includes a list of terrorism risk reduction measures. It also discusses 
the implementation of an integrated incremental program and links (in 
the form of matrices) specific physical and operational enhancement 
measures to normal maintenance and capital improvement programs 
associated with commercial buildings. It is intended for risk managers, 
facility managers, and design professionals. 

Chapter 3 discusses blast threats to buildings and physical enhancements 
that reduce the vulnerability to blasts. It is intended for design 
professionals and their blast consultants. 

Chapter 4 discusses chemical, biological, and radiological threats to 
buildings and physical and operational enhancements that reduce the 
vulnerability to these threats. It is intended for design professionals and 
their CBR consultants. 

Chapter 5 discusses operational security measures that reduce commercial 
building vulnerabilities to terrorist threats. It is intended for design 
professionals and security personnel. 

aCknOWLeDgMents 

This publication has been developed in collaboration with the 
Infrastructure and Geophysical Division of the Science and Technology 
Directorate of the Department of Homeland Security. 

Principal Authors: 

Frederick Krimgold, D.Tech., Virginia Tech
David Hattis, Building Technology Incorporated
Robert Smilowitz, Weidlinger Associates, Inc.
William Blewitt, Batelle
Terrence P. Ryan, Raytheon UTD


Contributors: 

Pax Williams, Batelle 

Expert Review Panel: 

Eric Letvin, URS Corporation 
Ken Mead, Centers for Disease Control and Prevention 
John Sullivan, Portland Cement Association 
Michael J. W. Kaminskas, Raytheon UTD 
Mark M. Hankewycz, the Protection Engineering Group, PC 
Mohamed Ettouney, Weidlinger Associates, Inc. 

Project Officer: 

Milagros Nanita Kennett 

Infrastructure and Geophysical Division 

Science and Technology Directorate 

US Department of Homeland Security 


taBLe OF COntents 

FOReWORD anD aCknOWLeDgMents
Background...................................................................
............................................................ i
Objective and 
Scope........................................................................
.........................................ii
Limitations 
.............................................................................
..................................................ii
Intended 
Audience.....................................................................
.............................................iii
Content and 
Organization.................................................................
.....................................iii
Acknowledgments..............................................................
..................................................... iv


1 integRateD inCReMentaL BUiLDing PROteCtiOn 

1.1 What is Integrated Incremental Building Protection 
................................................................... 1-1


1.1.1 Integration of Terrorism Risk Reduction in the Facility 
Management 
Process......................................................................
.......................1-1 

1.1.2 Incremental Approach Distributes Cost Over Time and Avoids Added 
Disruption 
.............................................................................
................................. 1-2 

1.1.3 
RiskReductionDecisions.......................................................
...............................1-3


1.2 Potential Threats 
.............................................................................
.................................... 1-4


1.2.1 
ExplosiveThreats.............................................................
......................................1-5


1.2.2 CBR Threats 
.............................................................................
.............................. 1-7


1.2.2.1 Chemical Agents 
.............................................................................
... 1-7


1.2.2.2 Biological Agents 
.............................................................................
.. 1-8


1.2.2.3 Radiological 
Threats......................................................................
..... 1-8


1.3 Terrorism Risk 
Reduction....................................................................
................................... 1-9


1.3.1 Categories of Risk Reduction Increments 
........................................................... 1-9


1.3.2 Implementation 
Considerations...............................................................
.......... 1-10


1.4 Special Issues Related to Existing Commercial Buildings 
........................................................... 1-11


1.5 Commercial Building Classifications 
.............................................................................
.......... 1-12


1.6 Facility Management Process for Existing Commercial 
Buildings................................................. 1-13


1.6.1 TheAcquisitionPhaseofCommercialBuildingFacilityManagement...........1-
14


1.6.2 The Redevelopment Phase of Commercial Building Facility Management ... 
1-15 

1.6.3 The Current Building Use Phase of Commercial Building Facility 
Management 
.............................................................................
........................... 1-17 

1.6.4 The Planning Phase of Commercial Building Facility 
Management............... 1-19


1.6.5 The Maintenance and Rehabilitation Budgeting Phase of Commercial 
Building Facility 
Management...................................................................
.........1-22 

1.6.6 The Maintenance and Rehabilitation Funding Phase of Commercial 
Building Facility 
Management...................................................................
.........1-24 

1.6.7 The Maintenance and Rehabilitation Implementation Phase of 
Commercial Building Facility Management 
...................................................... 1-25 

1.7 Planning and Managing Incremental Terrorism Risk Reduction 
................................................... 1-26


1.7.1 Step 1 Conduct a Due Diligence Terrorism Risk 
Assessment........................ 1-27


1.7.2 Step 2 Identify and Implement Initial Increment Integration 
Opportunities................................................................
....................................... 1-28 

1.7.3 Step 3 Assess Terrorism Risk 
........................................................................... 
1-29


1.7.4 Step 4 Develop a Security Master Plan 
............................................................ 1-30


1.7.5 
Step5 PlanIncrementalRehabilitationforSpecificBuildings.....................1
-31


1.7.6 Step 6 Stage Rehabilitation Increments 
......................................................... 1-32


1.7.7 
Step7 CoordinatewithTenantWork...............................................
...............1-33


1.7.8 Step 8 Define Budget Packaging 
..................................................................... 1-34


1.7.9 Step 9 Implement Integrated Incremental Rehabilitation Project 
Management 
.............................................................................
.......................... 1-35 

1.8 Terrorism Risk Assessment to Terrorism Risk Reduction 
........................................................... 1-36


2 MOVing FROM Risk assessMent tO iMPLeMentatiOn 
OF inCReMentaL BUiLDing PROteCtiOn 

2.1 Risk Assessment Process 
.............................................................................
......................... 2-1


2.1.1 Levels of Vulnerability Assessment 
...................................................................... 2-3

2.1.2 The Building Vulnerability Assessment Checklist 
............................................... 2-4


2.2 Scheduling Increments: Physical Protection and Strengthening Measures and 
Operational 
(Protective and Control) Measures 
.............................................................................
............ 2-5 

2.2.1 
PhysicalProtectionandStrengtheningMeasures...................................
............2-5


2.2.2 Operational Measures 
.............................................................................
.............. 2-5


2.3 Identifying Integration Opportunities for Incremental Building Protection 
...................................... 2-6


3 PRinCiPLes OF Design FOR Risk 
ReDUCtiOn ReLateD tO BLasts 

3.1 Selected Examples of Terrorist Attacks on 
Buildings................................................................... 
3-2


3.1.1 Baltic Exchange, City of London, April 1992 
...................................................... 3-3


3.1.2 World Trade Center, New York City, February 
1993............................................ 3-3


3.1.3 Bishopsgate, City of London, April 1993 
............................................................. 3-4


3.1.4 Town Center, Manchester, England, June 1996 
.................................................. 3-5


3.2 Performance Standards 
.............................................................................
........................... 3-6


3.3 Site Incremental Upgrades: Perimeter 
Protection...................................................................
.... 3-8


3.4 Incremental Building Rehabilitation Measures 
......................................................................... 3-
10


3.4.1 Building Envelope 
.............................................................................
.................. 3-10


3.4.2 
FragmentRetentionFilm........................................................
............................3-12


3.4.3 Laminated 
Glass........................................................................
........................... 3-15


3.4.4 Blast Curtains 
.............................................................................
.......................... 3-16


3.4.5 
GlazingCatchCable/BarRetrofit................................................
......................3-18


3.4.6 Energy-
AbsorbingCatchCableSystems...................................................
..........3-19


3.4.7 Unreinforced Masonry Wall Debris Control 
..................................................... 3-19


3.4.8 Other Facade Retrofits 
.............................................................................
........... 3-22


3.5 Nonstructural Members 
.............................................................................
......................... 3-22


3.6 Structural Retrofits 
.............................................................................
............................... 3-23


3.6.1 Columns 
.............................................................................
.................................. 3-24

3.6.2 Floor 
Systems......................................................................
.................................. 3-25


3.6.3 Load-Bearing Unreinforced Masonry Walls 
...................................................... 3-28


3.6.4 
TransferGirders..............................................................
.....................................3-29


3.7 Blast Protection Measures 
.............................................................................
..................... 3-29


3.8 Blast Protection Measure Cost Considerations 
........................................................................ 3-31


4 PRinCiPLes OF Design FOR Risk ReDUCtiOn ReLateD tO 
CHeMiCaL, BiOLOgiCaL, anD RaDiOLOgiCaL tHReats 

4.1 Overview of CBR 
Threats......................................................................
................................ 4-1


4.2 Principles of Design for Risk Reduction Related to CBR 
.............................................................. 4-2


4.3 Prioritization of CBR Vulnerabilities: Incremental 
Improvements.................................................. 4-3


4.3.1 Level 1, Operational Measures and Expedient 
Protection................................. 4-4


4.3.2 Level 2, Enhanced Physical Security 
.................................................................... 4-4


4.3.3 Level 3, Enhanced Sheltering in 
Place................................................................. 4-5


4.3.4 Level 4, Aerosol Filtration, Medium 
Level........................................................... 4-5


4.3.5 Level 5, Gas-Phase Filtration, Medium 
Level....................................................... 4-6


4.3.6 Level 6, Aerosol Filtration, High Level 
................................................................ 4-6


4.3.7 Level 7, Gas-Phase Filtration, High Level 
............................................................ 4-7


4.4 Design Guidance for CBR Protective Levels 
.............................................................................
. 4-7


4.4.1 Level 1, Operational Measures and Expedient 
Protection................................. 4-7


4.4.1.1 Scope and Capabilities 
....................................................................... 4-7


4.4.1.2 Methods and Requirements 
.............................................................. 4-8


4.4.1.3 Cost 
Considerations...............................................................
........... 4-13


4.4.2 Level 2, Physical 
Security.....................................................................
................ 4-14


4.4.2.1 Scope and Capabilities 
..................................................................... 4-14


4.4.2.2 Methods and Requirements 
............................................................ 4-14


4.4.2.3 Cost 
Considerations...............................................................
........... 4-17


4.4.3 Level 3, Enhanced Safe Rooms and Isolated 
Zones.......................................... 4-17


4.4.3.1 Scope and Capabilities 
..................................................................... 4-17

4.4.3.2 
Methods......................................................................
....................... 4-17


4.4.3.3 Cost 
Considerations...............................................................
........... 4-20


4.4.4 Level 4, Aerosol Filtration, Medium 
Level......................................................... 4-20


4.4.4.1 Scope and Capabilities 
..................................................................... 4-20


4.4.4.2 Methods and Requirements 
............................................................ 4-21


4.4.4.3 Cost 
Considerations...............................................................
........... 4-21


4.4.5 Level 5, Gas-Phase Filtration, Medium 
Level..................................................... 4-22


4.4.5.1 Scope and Capabilities 
..................................................................... 4-22


4.4.5.2 Methods and Requirements 
............................................................ 4-23


4.4.5.3 Cost 
Considerations...............................................................
........... 4-24


4.4.6 Level 6, Aerosol Filtration, High Level 
.............................................................. 4-24


4.4.6.1 Scope and Capabilities 
..................................................................... 4-24


4.4.6.2 Methods and Requirements 
............................................................ 4-24


4.4.6.3 Cost 
Considerations...............................................................
........... 4-25


4.4.7 Level 7, Gas-Phase Filtration, High Level 
.......................................................... 4-25


4.4.7.1 Scope and Capabilities 
..................................................................... 4-25


4.4.7.2 Methods and Requirements 
............................................................ 4-26


4.4.7.3 Cost 
Considerations...............................................................
........... 4-28


4.5 
Summary......................................................................
................................................... 4-28


4.6 CBR Protection Measures 
.............................................................................
...................... 4-30


5 PRinCiPLes OF Design FOR Risk ReDUCtiOn 
ReLateD tO OPeRatiOnaL seCURitY MeasURes 

5.1 Overview of Operational Security Measures 
............................................................................ 
5-1


5.2 Detection and Assessment Measures 
.............................................................................
......... 5-2


5.2.1 Exterior Intrusion Detection Systems 
.................................................................. 5-2


5.2.2 Interior Intrusion Detection Systems 
................................................................... 5-3


5.2.3 Video Assessment and Surveillance 
Systems........................................................ 5-3


5.2.4 Access Control 
Systems......................................................................
.................... 5-5


5.2.5 Vehicle Inspection Systems 
.............................................................................
...... 5-6


5.2.6 Duress Alarms 
.............................................................................
........................... 5-7


5.2.7 Mail/Package Screening 
.............................................................................
.......... 5-7


5.3 Interdiction/Response Measures 
.............................................................................
............... 5-9


5.3.1 Guard Force   Detection/Delay Role 
.................................................................. 5-9


5.3.2 
GuardForce Response/InterdictionRole.........................................
.............5-10


5.3.3 Response Force Contingency Planning 
............................................................. 5-10


5.4 Procedural Measures 
.............................................................................
............................. 5-11


5.4.1 Restricted Areas 
.............................................................................
...................... 5-11


5.4.2 Parking and Traffic 
Controls.....................................................................
.......... 5-12


5.4.3 
RestrictAccesstoFacilityInformation..........................................
.....................5-13


5.4.4 
EncourageEmployeeSupport.....................................................
.......................5-13


5.5 Preparedness Measures 
.............................................................................
......................... 5-13


5.5.1 Develop a Disaster Preparedness Plan 
............................................................... 5-14


5.5.2 Conduct Risk 
Assessments..................................................................
................. 5-14


5.5.3 Develop Mass Notification Systems 
.................................................................... 5-14


5.5.4 Evacuation Planning and Shelter In Place Preparation 
................................... 5-14


5.5.5 Monitor Emergency Systems and Resources 
..................................................... 5-15


5.5.6 Conduct Training Drills and Exercises 
.............................................................. 5-15


5.6 Security Master Planning 
.............................................................................
....................... 5-16


5.7 Additional Aspects of Operational Security Measures Related to Blast 
Events.............................. 5-17


5.7.1 Establish an Explosive Detection Program 
........................................................ 5-18


5.7.2 
EstablishBombThreatProcedures................................................
....................5-18


5.7.3 Establish Blast-Related Mail/Package Handling Procedures 
........................... 5-18


5.8 Additional Aspects of Operational Security Measures Related to CBR Events 
.............................. 5-19


5.8.1 Prevent Access, and Secure and Monitor Outdoor Air Intakes 
....................... 5-21


5.8.2 Establish CBR-Related Mail/Package Handling Procedures 
........................... 5-21


5.8.3 
AdditionalMeasures...........................................................
.................................5-22

5.9 Prioritization of Operational Security Considerations 
.............................................................. 5-23


5.9.1 
RetailBuildings..............................................................
......................................5-24


5.9.2 Office Buildings 
.............................................................................
...................... 5-24


5.9.3 Multi-Family Apartment Buildings 
..................................................................... 5-24


5.9.4 Hotel Security 
Measures.....................................................................
................. 5-25


5.10 Incremental Integration of Operational and Physical Security Measures 
Into a 
Risk Reduction Program: Flexibility and 
Tradeoffs................................................................... 
5-25 

5.11 Operational Security Protection Measures 
............................................................................. 
5-27


5.11.1 Physical Protection and Strengthening 
Buildings............................................. 5-27


5.11.2 Operational Measures 
.............................................................................
............ 5-28


5.11.3 Operational Measures Categorized into the Building Vulnerability 
Assessment Checklist 
.............................................................................
.............. 5-30 

BiBLiOgRaPHY.................................................................
.....................................................I


FEMA 459 / April 2008 

Risk Management Series 

Incremental Protection for Existing Commercial Buildings from Terrorist 
Attack: 
Providing Protection to People and Buildings

Integrated Incremental Building Protection 1 

1.1 What is integrated incremental building protection? 

Integrated incremental building protection is a process for improving safety 
in existing buildings with minimum cost and disruption of building 
function. Integrated, incremental protection of existing commercial 
buildings from terrorist attacks applies the basic principles of 
security evaluation and design to the physical and operational demands 
of existing buildings. Rehabilitation of existing buildings poses 
special challenges not faced in the case of design
and construction of new buildings. Site conditions are pre-defined. 
Configuration and structural system are given, and current building 
occupants must be accommodated during the rehabilitation process. 
Investments in rehabilitation of existing buildings may also not be 
justified in light of the expected remaining useful life of the 
building.

[text box]
The term  building protection  or  protection,  as used in this chapter,
refers to a specific category of building  rehabilitation  that
addresses terrorism risk reduction. When the term  rehabilitation  is
used it refers to general activities that may or may not include
terrorism risk reduction.
[end of text box]

1.1.1 Integration of Terrorism Risk Reduction in the Facility Management 
Process 

The integrated, incremental protection process is based on the identification 
of increments of security enhancement that may be 
integrated into the normal schedule of maintenance and capital 
improvement. For example, when window replacement is considered 
for energy conservation or modernization, blast resistance can be 
enhanced at the same time with relatively little added expense. The 
advantage of this approach to rehabilitation is that it reduces the cost 
of implementing security enhancements and it reduces the cost due to 
added business interruption related to a single purpose intervention 
in the building. The integration of terrorism risk reduction measures 
with normal maintenance and capital improvement takes advantage 
of regularly scheduled design, contracting, and staging to implement 
security enhancements at marginal added cost. The identification of 
specific increments of security enhancement allows these improvements 



to be made opportunistically as normal work is carried out on various 
components of the building. 

Figure 1-1: Schematic Integration Opportunities. 

Integration of specific increments of terrorism risk reduction is illustrated 
in the three buildings of Figure 1-1. These examples show the 
opportunistic character of the incremental approach. By pre-identifying 
the increments of risk reduction, implementation can effectively 
 piggy-back  on work that arises in the normal course of building 
maintenance and capital improvement. For example, roofs are usually 
replaced on a schedule of 15 to 20 years. Strengthening the roof/wall 
connections and improving the blast resistance of the structure is 
relatively easy and inexpensive to do during a scheduled roof 
replacement. Provisions 
for opening up the roof and erecting scaffolding can serve both the purposes 
of roof renewal and terrorism risk reduction. 

In a similar way, exterior wall maintenance and window replacement provide 
the opportunity for reducing outdoor air penetration into the building 
and improving the blast resistance of the windows. 
Work on interior walls provides the opportunity for strengthening of blast 
resistance and the creation of safe areas. 

1.1.2 Incremental Approach Distributes cost Over Time and Avoids Added 
Disruption 

Over time, the accumulated effect of the incremental measures will 
be the same as a comprehensive one-stage building rehabilitation that 
would require closing the building and a major one-time investment. The 
incremental approach spreads the cost of security enhancement over a 
period of years, reducing the impact of rehabilitation costs. 

Because the integrated incremental rehabilitation approach is designed 
to accommodate business continuity and a continued revenue stream 
from the commercial building, it is closely tied to the schedules and 
requirements of specific occupancies. 

Investment in the rehabilitation of existing commercial buildings requires a 
strong business case. Sustainable costs must be justified and supported 
by future revenue generated by the building. Factors to consider in the 
justification of rehabilitation investment include: estimation of the 
remaining lifetime of the building, desirability for potential 
occupants, and the market value of security enhancements. 

1.1.3 Risk Reduction Decisions 

This manual is designed primarily for application in existing office, 
retail, multi-family residential, and hotel buildings. Owners of existing 
commercial buildings face a sequenced set of cost decisions diagrammed 
in Figure 1-2. On the basis of risk assessment methodologies, building 
owners can evaluate the terrorism risk for specific buildings. Based on the 
informed risk perception, the building owner may decide that building 
protection is not necessary. Alternatively, the building owner may decide 
to invest in terrorism risk reduction measures. If the decision is made 
to invest in terrorism risk reduction, the next decision is whether to 
replace the building, i.e., demolish or sell it and build a new one, or to 
rehabilitate the building to reduce terrorism risk. 

Owners who decide to rehabilitate the building may initiate a single-
stage intervention. Such an approach typically requires the evacuation 
of the building for a significant period of time and a major one-time 
rehabilitation investment. Both these factors may be difficult to accept 
in the case of an existing commercial building with limited remaining 
asset life. An alternative approach is the incremental rehabilitation of the 
building. 

Figure 1-2: Cost decision scheme. 

The integrated incremental building protection approach has the 
advantage of reduced and distributed costs. While extending the time of 
implementation, an integrated incremental building protection program 
will eventually provide the same level of protection that can be supported by 
the revenue of an existing commercial building. 

Careful planning and efficient use of opportunities for low cost risk 
reduction can make terrorism risk reduction feasible even for marginal 
existing commercial buildings. 

1.2 Potential Threats 

Commercial building owners who want to implement measures 
that may save lives and property must understand the nature of 
the hazards that can affect their buildings and the impacts of 
those hazards on the buildings. The term  threat  is typically used to 
characterize manmade disasters (technological accidents) or terrorism 
hazards. Because there have been few terrorist attacks in the United States 
and data for manmade threats is scarce, predictions of the magnitude 
and recurrence of terrorist attacks are largely subjective. 

Aggressor tactics may include: moving vehicle bombs, stationary vehicle 
bombs, bombs delivered by persons (suicide bombers), exterior attacks 
(thrown objects like rocks, Molotov cocktails, hand grenades, or hand-
placed bombs), stand-off weapons attacks (rocket-propelled grenades, 
light antitank weapons, etc.), ballistic attacks (small arms and high-power 
rifles), covert entries (gaining entry by false credentials or 
circumventing security with or without weapons), mail bombs (delivered 
to individuals), supply bombs (larger bombs processed through shipping 
departments), airborne contamination (chemical, biological, and 
radiological [CBR] agents used to contaminate the air supply of a 
building), and waterborne contamination (CBR agents injected into the 
water supply). This section focuses on explosive threats, chemical 
agents, biological warfare agents, and radiological attacks. 


1.2.1 Explosive Threats 

The explosive threat is particularly significant, because all of the 
ingredients required to assemble an improvised explosive device are 
readily available at a variety of farm and hardware stores. The intensity of 
the explosive detonation is a function of the weight of the explosive. 
For explosive threats, the weight of the explosive depends on the means 
of transportation and delivery. Explosives weigh approximately 100 
pounds 
per cubic foot and, as a result, the maximum credible threat corresponds 
to the weight of explosives that can be packaged in a variety of containers 
or vehicles. The U.S. Department of Defense (DoD) developed a chart 
indicating the weight of explosives and deflagrating materials that may 
reasonably fit within a variety of containers and vehicles (see Table 
1-1). 
The table indicates the safe evacuation distances for occupants of 
conventional buildings, based on the ability of the buildings to withstand 
severe damage or resist collapse. 

Operational security measures (see Chapter 5) define the areas within 
or around a building at which a device may be located, undetected by 
the building facility staff. These security procedures include screening of 
vehicles, inspection of delivered parcels, and vetting hand carried 
bags. The extent to which this inspection is carried out will determine 
the size of an explosive device that may evade detection. Despite the 
most vigilant attempts, however, it is unrealistic to expect complete 
success in preventing a small explosive threat from evading detection. 
While it is unlikely that a large explosive threat may be brought into 
a building, a parcel sized device may be introduced into publicly 
accessible lobbies, garages, loading docks, cafeterias, or retail 
spaces and a smaller explosive device may be brought anywhere into a 
building. 

Only two domestic terrorist bombings involved the use of large quantities 
of High Energy explosive materials in the United States. (For more 
information on High Energy explosives, see FEMA 426, Reference Manual 
to Mitigate Potential Terrorist Attacks Against Buildings, Chapter 4.) 
Although these events represent the largest explosions that have 
occurred to date, they may not represent the current domestic explosive 
threat. The 1995 explosion that collapsed portions of the Murrah 
Federal Office Building in Oklahoma City contained 4,800 pounds of 
ammonium nitrate and fuel oil (ANFO) and the 1993 explosion within the 
parking garage beneath 
the World Trade Center complex contained 1,200 pounds of urea nitrate. 

Every year, approximately 1,000 intentional explosive detonations are 
reported by the Federal Bureau of Investigation (FBI) Bomb Data 
Center. The FBI statistics indicate that the majority of the domestic events 
contain significantly smaller weights of Low Energy explosives. (For 
more information on Low Energy explosives, see FEMA 426, Chapter 4.) 

Table 1-1: Safe Evacuation Distances from Explosive Threats 

Although the majority of the explosions reported by the FBI targeted 
residential properties and vehicles, 63 took place in educational facilities, 
causing a total of $68,500 in property damage. Other than the attack 
against the Murrah Federal Office Building, no explosive devices were 
detonated at a Federal government-owned facility, and only nine were 
detonated at local/state government facilities. Nearly 80 percent of the 
people known to be involved in bombing incidents were young offenders, 
and less than 0.5 percent of the perpetrators were identified as members 
of terrorist groups. Vandalism was the motivation in 53 percent of the 
known intentional and accidental bombing incidents, and the timing of 
the attacks was fairly uniformly distributed throughout the day. 

1.2.2 CBR Threats 

Like explosive threats, CBR threats may be delivered externally or 
internally to a building. While there may not be official warning of a CBR 
event, the best defense may be to be alert to signs of a release. 

There are three potential methods of CBR attack: 


A large exterior release originating some distance away from the 
building (includes delivery by aircraft) 

A small localized exterior release at an air intake or other opening in 
the exterior envelope of the building 
 
A small interior release in a publicly accessible area, a major egress 
route, or other vulnerable area (e.g., elevator lobby, mail room, 
delivery, receiving and shipping) 

The following paragraphs provide summary information about each of 
the components of CBR attacks chemical agents, biological agents, and 
radiological threats. 

1.2.2.1 Chemical agents 

Toxic chemical agents can present airborne hazards when dispersed as 
gases, vapors, or solid or liquid aerosols. Unlike biological or radiological 
agents, chemical agents generally produce immediate effects. In most 
cases, toxic chemical agents can be detected by the senses, although a 
few are odorless. Their effects occur mainly through inhalation, 
although they can also cause injury to the eyes and skin. 

1.2.2.2 Biological agents 

Biological agents are organisms or toxins that can kill or incapacitate 
people and livestock, and destroy crops. The three basic groups of 
biological agents that would likely be used as weapons are bacteria, 
viruses, and toxins. 

 
Bacteria. Bacteria are small free-living organisms that reproduce by 
simple division and are easy to grow. The diseases they produce often 
respond to treatment with antibiotics. 
 
Viruses. Viruses are organisms that require living cells in which to 
reproduce and are intimately dependent upon the body they infect. 
The diseases they produce generally do not respond to antibiotics; 
however, antiviral drugs are sometimes effective. 
 
Toxins. Toxins are poisonous substances found in, and extracted 
from, living plants, animals, or microorganisms; some toxins can be 
produced or altered by chemical means. Some toxins can be treated 
with specific antitoxins and selected drugs. 
Most biological agents are difficult to grow and maintain. Many break 
down quickly when exposed to sunlight and other environmental factors, 
while others such as anthrax spores are very long lived. There are three 
methods for delivery of biological agents: 

Aerosols. Biological agents are dispersed into the air, forming a fine 
mist that may drift for miles. Inhaling the agent may cause disease in 
people or animals. 
 
Animals. Some diseases are spread by insects and animals, such as fleas, 
flies, mosquitoes, and mice. Deliberately spreading diseases through 
livestock is also referred to as agroterrorism. Person-to-person spread 
of a few infectious agents is also possible. Humans have been the 
source of infection for smallpox, plague, and the Lassa viruses. 
 
Food and water contamination. Some pathogenic organisms and toxins may 
persist in food and water supplies. Most microbes can be killed, and 
toxins deactivated, by cooking food and boiling water. 


1.2.2.3 Radiological threats 

This manual does not address the severe and various effects generated by 
nuclear events, including blinding light, intense heat (thermal radiation), 
initial nuclear radiation, blasts, fires started by the heat pulse, and 
secondary fires caused by the destruction. 

Terrorist use of a radiological dispersion device (RDD), often called  dirty 
bomb,  is considered more likely than use of a nuclear device. These 
radiological weapons are a combination of conventional explosives and 
radioactive material designed to scatter dangerous and sublethal 
amounts of radioactive material over a general area. Very little 
technical knowledge is required to build and deploy such radiological 
weapons as compared to that of a nuclear device. Also, radioactive 
materials, used widely in medicine, agriculture, industry, and 
research, are more readily available and easy to obtain compared to the 
weapons-grade uranium or plutonium required for a nuclear device. 

1.3 Terrorism Risk Reduction 

1.3.1 Categories of Risk Reduction Increments

The adoption of risk reduction increments as part of enhancing, 
retrofitting, or rehabilitating a building can be an effective 
approach in reducing vulnerability to terrorist attacks. There is a 
range of risk reduction increments that can be used to enhance security 
in case of blasts and chemical, biological, and radiological hazards. For 
this manual, two categories are identified: 

Physical Protection and Strengthening of Existing Buildings. Physical 
protection and strengthening deals with structural and non-structural 
modifications of existing buildings. While new buildings may include 
protective measures to reduce the potential impact of terrorist 
attacks, existing buildings may be at larger risk because they were 
constructed without the appropriate safety measures to withstand 
potential attacks. Thus, improving the safety and structural integrity 
of existing buildings is often the best way to reduce the impact of 
terrorist attacks on such structures. When a terrorism threat occurs, 
it can directly damage a target building or indirectly cause secondary 
effects in adjacent buildings (collateral damage). Poorly engineered 
and constructed buildings cannot usually resist the forces generated 
by a blast event or serve as safe havens in case of CBR attacks. 
 
Operational Measures. Unlike other risk reduction increments that 
improve the resistance of buildings to disasters, protective and control 
measures focus on protecting structures by deflecting the destructive 
forces from vulnerable structures and people. Ideally, a potential 
terrorist attack is prevented or pre-empted through intelligence 
measures. If the attack does occur, physical security measures combine 
with operational forces (e.g., surveillance, guards, and sensors) 
to provide layers of defense that can delay or thwart the attack. 
Deception may be used to make a facility appear to be more protected 
or lower risk than it actually is, making it a less attractive target. 
Deception can also be used to misdirect an attacker to a portion 
of the facility that is non-critical. Because of the interrelationship 
between physical and operational security measures, it is imperative 
for building owners and security professionals to define what extent of 
operational security is planned for various threat levels. 

1.3.2 Implementation Considerations 

The implementation of some risk reduction increments may create 
public inconvenience. For example, the placement of bollards, closure 
of public streets, and rehabilitation of buildings may affect people s 
access to public places or have a negative effect on community aesthetic. 
The implementation of mitigation enhancements involves the following 
considerations. 

Costs and Benefits. When implementing a risk reduction increment, 
the benefits (reduction of potential future losses) of implementing 
the option should outweigh the costs (capital cost of protection 
measure, operating cost of protection measure, and adverse effects on 
business). 
 
Legal Authority. A risk reduction increment should not be undertaken 
without the appropriate legal authority. Building owners should 
determine whether they have the legal authority to implement 
selected mitigation options. For example, creating standoff distances 
in urban areas can violate zoning ordinances and building set-back 
requirements. 
 
Adverse Effects on the Built Environment. Some risk reduction increments 
may have a negative effect on the built environment. When selecting 
mitigation measures, building owners should scrutinize the potential 
effects on: 
 
Traffic/vehicular mobility 
 
Pedestrian mobility 
 
Ingress and egress to the building 
 
Other building operations 
 
Aesthetics 

Interference with first responders 

Impact on the Natural Environment. Considering whether the recommended 
risk reduction increments will have a negative effect on environmental 
assets, such as air quality, water quality, threatened and endangered 
species, and other protected natural resources is also important. 

1.4 Special Issues Related to Existing Commercial Buildings 

Certain features of existing buildings clearly distinguish them from 
newly designed and constructed buildings and may limit the range 
of security mitigation options available for consideration: 

The physical fabric of the existing building may be concealed or 
unknown. New buildings are designed and specified in terms of 
materials and systems whose characteristics are fully defined and that 
conform to known standards. By contrast, the design basis, materials, 
and standards that governed the design and construction of currently 
existing buildings are more ambiguous. Determining the inherent 
response of the building and its systems to blast forces, for example, 
may not be possible. 
 
Existing buildings are likely to have been designed to conform to 
older, and possibly archaic, building codes. Their performance under 
current physical conditions may be difficult to determine or control. 
 
The relationship of existing buildings to the surrounding site, roads, 
access, standoff, utilities, and adjacent buildings is fixed and not 
subject to significant alteration. 
 
The physical fabric of an existing building may constrain or prohibit 
the implementation of specific risk reduction measures that are 
considered in new building design as a matter of course. 
 
Existing buildings are usually occupied and perform a variety of 
business, cultural, and life support functions for their occupants. 
This may constrain or prohibit the implementation of specific 
risk reduction measures unless business or service interruption is 
acceptable. 
 
Compared to new buildings, existing buildings often have a limited 
useful remaining lifetime, which dictates a much shorter payback 
period for investments in security enhancement. 
 
Conditions of financing capital improvements in existing buildings 
may differ from those applicable to new buildings. 
The commercial buildings addressed in this manual are office buildings, 
retail buildings, multifamily apartment buildings, and hotel buildings. 
All four categories have features that may limit the range of security 
mitigation options available for consideration: 

Commercial buildings are income-generating systems for their 
owners. Interruption of building operations interrupts the flow of 
income and is equivalent to an added cost when considering any 
capital improvement. This feature makes commercial buildings ideal 
candidates for integrated incremental enhancements, which better 
manage costs and disruption. 
 
Access control is a significant aspect of security enhancement for 
buildings. Commercial office, retail, hotel, and multifamily apartment 
buildings require public access. The extent to which that access can be 
controlled may be limited. 


1.5 Commercial Building Classifications 

Commercial buildings are often classified for real estate purposes 
into three classifications Classes A, B, and C. The Urban 
Land Institute, a noted authority on commercial land uses, 
says the following about these classifications in its Office Development 
Handbook. Class A space can be characterized as buildings that have 
excellent location and access, attract high quality tenants, and are 
managed professionally. Building materials are high quality and rents are 
competitive with new buildings. Class B buildings have good locations, 
management, and construction, and tenant standards are high. Buildings 
should have very little functional obsolescence and deterioration. Class 
C buildings are typically 15 to 25 years old but are maintaining steady 
occupancy. Tenants filter from Class B to Class A and from Class C to Class 
B. In a normal market, Class A rents are higher than Class B, which are 
above Class C. 

Facility management practices in commercial buildings vary as a function 
of this classification (Class A, B, or C) as well as the type and scale 
of ownership. The effectiveness of physical and operational security 
enhancements depends on the quality of the facility management. 

1.6 Facility Management Process for Existing Commercial Buildings 

Facility management processes for existing commercial buildings 
vary in detail by type of occupancy (office, retail, multifamily, 
hotels, etc.). The complexity and completeness of facility 
management practices may also vary by type of ownership (real estate 
investment trust [REIT], pension fund, insurance company, partnership, 
individual, etc.) and by scale of operation (dispersed portfolio, 
concentrated portfolio, individual building). Despite these variations, a 
generic facility management process consists of seven phases of activities: 

1. Acquisition 
2. Redevelopment 
3. Current Building Use 
4. Planning 
5. Maintenance and Rehabilitation Budgeting 
6. Maintenance and Rehabilitation Funding 
7. Maintenance and Rehabilitation Implementation 

Figure 1-3: Typical facility management process. 

Figure 1-3 depicts these seven distinctive phases in the overall facility 
management process and the activities associated with each phase, 
which are discussed in detail in the following sections. The facility 
management process is sequential, progressing from acquisition through 
implementation of rehabilitation in any given building. It begins with 
acquisition because commercial buildings normally change ownership 
every seven to 15 years, and this usually entails new financing and 
insurance, providing a unique opportunity for facility assessment and 
initial redevelopment. A current owner of an existing commercial 
building, as opposed to a prospective owner, begins the facility 
management process with the third phase, the use phase. An owner who 
has a large inventory of buildings is likely to have ongoing activities in 
all of these phases in different buildings. 

This process is generic, and while there may be variations, commercial 
building owners generally follow it, either explicitly or implicitly. 

The following sections briefly describe each phase, the activities therein, 
and some factors that influence those activities (indicated graphically 
by downward arrows for factors outside the owner organization and 
upward arrows for factors internal to the organization). 

1.6.1 The Acquisition Phase of Commercial Building Facility Management

The acquisition phase of the typical commercial building facility 
management process consists of due diligence activities and is influenced 
by significant internal and external pressures, as depicted in Figure 1-4. 

Figure 1-4: Acquisition phase. 

Commercial building acquisitions initiate the facility management process 
for all owners who are not also developers or merchant builders. The due 
diligence process that precedes an acquisition is intended to identify, and 
quantify if possible, all the liabilities and risks or potential 
liabilities and risks related to the asset being acquired. 

Acquisition phase decisions are influenced by three factors: 

Market Conditions. External local conditions of the commercial rental 
market are the principal factors governing commercial building 
acquisition, regardless of the short-term or long-term strategic 
objectives of the purchaser. This is true for all types of owners, be they 
REITs, pension funds or other fiduciary institutions, partnerships, or 
individuals. 

Lenders and Insurers. Lenders and insurers are important external 
participants in many commercial building acquisitions, and each 
carry out due diligence functions to determine the risks and potential 
liabilities in any given deal. By their nature, lenders and insurers 
spread their risks over a wider range of investments than that 
presented to an owner in a specific acquisition. The insurability of the 
acquired property is of great concern to commercial building owners, 
but the cost of insurance is of lesser concern because the cost may be 
passed on to tenants in many commercial properties. 
 
Risk Management. Many commercial building owners have formally 
established internal risk management functions within their 
organizations. These risk managers participate in the due diligence 
analyses carried out prior to acquisition. The rigor of internal due 
diligence varies from owner to owner. 


1.6.2 The Redevlopment Phase of Commercial Building Facility Management 

The redevelopment phase of the typical commercial building facility 
management process consists of various types of capital improvements, 
and is influenced by significant internal and external pressures, as 
depicted in Figure 1-5. 

Figure 1-5: Redevelopment phase. 

The types of redevelopment phase capital improvement projects vary 
as a function of the building s classification (A, B, or C). They generally 
consist of: 

Architectural upgrading of entrances, lobbies, and public areas 
 
Architectural upgrading of facades 
 
Upgrading of the heating, ventilation, and air-conditioning (HVAC) 
systems 
 
Environmental and other risk remediation work identified in the due 
diligence process 
 
Upgrading of life safety systems 
Redevelopment phase decisions are influenced by three factors: 
 
Market Conditions. Commercial properties in a given classification must 
compete with neighboring, similarly classified properties. Local 
architectural traditions and fashions and historic preservation are 
significant factors determining the specific nature of various capital 
improvement projects. 
 
Lenders and Insurers. External lenders and insurers may require specific 
capital improvements as a condition of the deal. For example, they 
may require the replacement of a questionable roof or HVAC system. 
These are generally the direct result of the due diligence analyses. 

Owner Policies. Owners  marketing and architectural policies are the 
principal internal factors governing capital improvement decisions in 
the redevelopment phase. 

1.6.3 The Current Building Use Phase of Commercial Building Facility 
Management   

The current building use phase of the typical commercial facility 
management process consists of four categories of activities and is 
influenced by significant internal and external pressures, as depicted in 
Figure 1-6. 

Figure 1-6: use phase. 

Occupancy. The primary function of this category is occupancy of 
commercial space by tenants. Support functions are administrative, 
such as collecting rents and addressing tenants  concerns. Ancillary 
functions may be recreational, such as operating a health club, pool, 
or spa, and social, such as operating a lecture room, restaurant, or 
similar facility. The specific functions may vary depending on the 
building classification (A, B, or C). 

Occupancy functions are carried out in each building by the tenants 
and facility managers. Each of these functions is subject to security risk 
and can be disrupted by terrorist attacks. 

Operation. Facility operation consists of all the activities and functions 
that are required to support the occupancy. Examples of facility 
operation include mechanical functions (heating, cooling, and 
ventilation), electrical functions (lighting, communications, and 
alarm), and plumbing functions. Operation functions may be carried out by 
custodial staff of the owner and/or by contractors. Each of these 
functions is subject to security risk and can be disrupted by terrorist 
attacks. 

Maintenance. Maintenance includes all the activities required to 
enable the occupancy and operation of the building continuously 
over time. They can be broken down into custodial maintenance, 
routine maintenance, and repair. Maintenance functions may be carried out by 
custodial staff of the owner and/or by contractors. In some cases, 
tenants or their contractors may carry out some maintenance functions. 

Scheduled Facility Assessment. Facility assessment, which less 
sophisticated commercial building owners may not carry out 
systematically, consists of the survey or inspection of the buildings 
on a scheduled basis. It may also include a review of documents, 
such as archival building plans, for retrieving specific information. 
The purpose(s) of the surveys or inspections is to determine facility 
conditions in relation to one or more of the following categories: 
 
Specific environmental hazards 

Preventive maintenance needs 
 
Asbestos 

Structural hazards 
 
Lead paint 

Fire/life safety 
 
Lead 

Environmental quality 
 
Radon 

Energy use/conservation 

User complaints 

Accessibility 

Maintenance needs 

Other 


These surveys may or may not be coordinated by schedule, content, 
personnel, etc. Facility managers may or may not use prepared 
inspection forms or checklists. Finally, the extent and specific nature of 
recordkeeping and reporting by facility managers may vary. 

Current use phase decisions are influenced by two factors: 

Federal and State Programs. Various external programs may establish 
requirements affecting the use of commercial buildings that have 
facilities implications (e.g., Americans with Disabilities Act [ADA] 
and Occupational Safety and Health Administration [OSHA] 
requirements). 

Specific surveys or inspections may be mandated by State or local 
laws/programs. These surveys/inspections may be carried out by a 
variety of entities: 

Federal personnel (e.g., from OSHA or the Environmental 
Protection Agency) 
 
State/city/county personnel (e.g., fire marshal, code 
enforcement, environmental, health) 

Commercial building personnel (e.g., custodial or facility 
managers) 
 
Commercial building contracted personnel (e.g., asbestos 
inspectors) 

Consultants 

Complaints by Occupants. Complaints by tenants are a potentially 
significant internal pressure on the facility management process. 

1.6.4 The Planning Phase of Commercial Building Facility Management 

The planning phase consists of projecting and forecasting future needs. 
It can be carried out periodically or continuously, and the time period 
covered by the projections and forecasts may vary. The owner, with or 
without the assistance of consultants, may carry out planning functions. 
Planning consists of two separate but related activities strategic planning 
and facility planning and is affected by significant internal and external 
pressures, as depicted in Figure 1-7. 

Strategic Planning. Strategic planning attempts to formulate future 
business strategy by analyzing and forecasting financial trends as well as 
national, regional, and local commercial space markets. Many owners 
acquire properties for a limited period of time, and many have an exit 
strategy in place at the time of acquisition. Strategic planning addresses 
such issues as: 

Should the property classification (A, B, or C) be upgraded or 
downgraded? 
 
Should the exit strategy be accelerated or prolonged? 




Figure 1-7: Planning phase. 

Should trends in the insurance market revise current investment 
programs? 

Should specific major capital investments be considered? 

Strategic planning is usually carried out at the owner s headquarters 
and addresses the owner s entire commercial building portfolio or large 
segments of it. 

Facility Planning. Facility planning consists of preparing short-and long-
range facility plans. It combines the products of two distinct activities the 
strategic plan and the facility assessment (see Figure 1-6) into a detailed 
projection of facility requirements. The projection may cover a defined time 
frame, such as 5 years. 

Different owners may use different classifications of projects in their 
facility plans, reflecting a variety of legal, administrative, 
jurisdictional, and other factors. However they may be classified, a 
comprehensive facility plan should include the following elements: 

New construction 
 
Additions to existing buildings 
 
Renovations of existing buildings 
 
Building systems replacements 
 
Building systems repairs 
 
Scheduled maintenance 
 
Preventive maintenance 
 
Building disposition (change of use, sale, demolition) 


The plan identifies the time frames for accomplishing each project, and it 
may include cost estimates. 

If effective, the facility plan is used as a budgeting tool and provides 
direct inputs into the budget process. It should be revised and updated on a 
routine basis to reflect: 

Changes in the strategic plan (including market conditions) 
 
Revised facility assessments 
 
Budgeting and funding realities 

Facility planning usually begins at the individual building or project level 
and entails the flow of information up the management hierarchy for 
final capital decision-making and budgeting at the owner s headquarters 
in the case of large portfolios. 

Planning phase decisions are influenced by three factors: 

Government Mandates. Federal, State, and local government agencies 
may establish external requirements affecting facility planning in the 
planning phase. These requirements may have facility rehabilitation 
implications. 
 
Insurance Carriers and Brokers. External private property and 
casualty insurance companies often require surveys or inspections 
of commercial buildings on an annual or other scheduled basis. 
Insurance carriers are more than willing, when asked, to provide 
building owners with Loss Control and Prevention Reports that 
include recommendations for loss prevention. Insurance brokers also 
employ loss/risk specialists. 
 
Board Policies. In terms of internal influences, boards of directors may 
occasionally adopt written policies on issues of business and social 
significance that can affect both strategic and facility planning. These 
policies guide the actions of the owner organization. 


1.6.5 The Maintenance and Rehabilitation Budgeting Phase of Commercial 
Building Facility Management  

The budgeting phase consists of the projection of future financial 
resources required to meet future needs. It is carried out annually 
covering a period of 1 or more years). Each local or regional facility 
manager initiates it with input from his or her staff. In the case of 
large portfolio owners, the facility budget process is initiated locally or 
regionally, and is overseen centrally. The facility budgeting is a process 
that can be thought of as percolating up through the organization. It is 
affected by external government fiscal regulations and lender requirements, 
and internal risk management policies and budget 
constraints, as depicted in Figure 1-8. 

Figure 1-8: budgeting phase. 

Three elements of the budget are relevant to the discussion of facility 
management: 

. Capital 
. Maintenance 
. Insurance 

Capital Budgets. Capital generally relates to the acquisition of 
buildings and major systems, which is not annual or repetitive, and 
which can therefore be amortized. The distinction between capital 
and maintenance budgets may vary among different commercial 
building owners. At one extreme is a total separation, mandated 
by law, labor jurisdiction, or other factor. At the other extreme is a 
rather unclear separation between the two funding mechanisms. 
 
Maintenance Budgets. Maintenance budgets generally relate to 
recurring annual expenditures and address existing inventories of 
buildings and systems without adding to the inventories. 
 
Insurance Budgets. Financial resources earmarked for insurance may 
be used in different ways, including the purchase of third-party 
insurance and/or the funding of a self-insurance reserve. Property 
and general liability insurance are relevant to facility management 
considerations. 

Budgeting phase decisions are influenced by four factors: 

Government Fiscal Regulations. Federal, State, and local government 
agencies have historically established external requirements dealing 
with fiscal responsibility of commercial property owners. A variety 
of Security and Exchange Commission regulations apply to REITs. 
Pension funds are subject to a variety of fiduciary requirements. 
Partnerships are subject to a variety of State and Federal regulations. 
One important objective of these regulations is to ensure the 
responsible stewardship of third party resources. These requirements 
may have facility rehabilitation implications, if resources are 
expended in an irresponsible manner. Additionally, these regulations 
may determine, directly or indirectly, the length of time an acquired 
real estate asset must be held and, therefore, what the owner s 
planning horizon should be. 
 
Lender Requirements. Commercial lenders impose requirements 
on building owners who use mortgage financing for capital 
improvements. Often, the lender requires the purchase of a 
particular type of insurance coverage. 
 
Budgetary Constraints. Internally, political and economic conditions 
may place limits on commercial building capital and maintenance 
budgets. The problem is often exacerbated by unfunded mandates 
imposed on commercial buildings by Federal and State agencies. 

Risk and Insurance Management. Internally, the owner organization s 
risk and insurance management may directly or indirectly affect 
insurance decisions in the budgeting phase of the process. 

1.6.6 The Maintenance and Rehabilitation Funding Phase of Commercial Building 
Facility Management  

The funding phase consists of those activities required to obtain the 
financial resources to meet the budgets. It is influenced externally by 
regional and local economic conditions and bond financing regulations, 
as depicted in Figure 1-9. 

Figure 1-9: Funding phase. 


The funding of commercial building budgets in general, and of the three 
budget elements of capital improvement, maintenance, and insurance, 
varies among owner organizations. Commercial building owners can fund 
their budgets by various combinations of equity and debt. 

Funding phase decisions are influenced by two factors: 

Regional and Local Economic Conditions. Externally, the funding of 
commercial building construction is subject to local and national 
socioeconomic conditions well beyond the control of the building 
owner. Construction funding depends on interest rates, the owner s 
bond rating, and similar parameters. 

Bond Financing Regulations. The local administrative procedures and 
structure in place to obtain bond financing will have a significant 
impact on the ability of commercial building owners to achieve their 
objectives, regardless of whether they include terrorism risk reduction 
or not. Certain types of expenditures out of the proceeds of a bond 
issue, such as operations or maintenance, may be prohibited by the 
conditions of the bond. 

1.6.7 tHe MaintenanCe anD ReHaBiLitatiOn 
iMPLeMentatiOn PHase OF COMMeRCiaL 
BUiLDing FaCiLitY ManageMent 

The implementation phase includes design and construction and can 
be broken into three categories of projects, all of which are relevant to 
existing buildings: 

Building acquisition projects 
 
Capital improvement projects 
 
Maintenance projects 


The implementation phase is primarily affected by external Federal and 
State programs and building code requirements, as depicted in Figure 
1-10. 

Figure 1-10: Implementation phase. 

Acquisition includes new building construction and the acquisition of 
existing buildings. Acquisition of existing buildings is discussed above as 
the first phase of the facility management process. 

Capital improvement and maintenance projects are managed by the 
commercial building owner s staff and carried out by the staff and 
contractors. The management of these two categories may be separated or 
combined, depending on issues of labor jurisdiction and legal authority. 

Implementation phase decisions are influenced by two factors: 


Federal and State Mandates and Programs. Externally, Federal and State 
programs may establish requirements affecting the implementation 
phase (e.g., ADA and OSHA requirements). 
 
Codes and Code Enforcement. Also externally, building codes impose 
requirements on the implementation phase in cases of repair, 
alteration, or addition to existing buildings. These requirements may 
be enforced by a State or local agency. Such requirements can add 
costs to a project and jeopardize feasibility, unless done incrementally. 


1.7 PLanning anD Managing 
inCReMentaL teRRORisM Risk 
ReDUCtiOn 

The implementation of an integrated incremental building protection 
program is supported by decisions and actions in each phase of the 
facility management process described in the preceding section. 

There are nine steps of an incremental terrorism risk reduction program: 

1. Conduct a Due Diligence Terrorism Risk Assessment 
2. Identify and Implement Initial Increment Integration 
Opportunities
3. Assess Terrorism Risk 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work 
8. Define Budget Packaging 
9. Implement Integrated Incremental Rehabilitation Project 
Management

Each of these steps relates to one (or more) of the facility management 
phases, as illustrated in the following table. 

Table 1-2: Steps of an Incremental Terrorism Risk Reduction Program 

Facility Management 
Process Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment 
2. Identify and Implement Initial Increment Integration Opportunities 
3. Assess Terrorism Risk 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work 
8. Define Budget Packaging 
9. Implement Integrated Incremental Rehabilitation Project Management 
Redevelopment Use Planning Budgeting Funding Implementation 

1.7.1 steP 1 COnDUCt a DUe DiLigenCe teRRORisM Risk assessMent 

This step is implemented in the acquisition phase of the facility 
management process. It may be performed by the owner (buyer), lender, 
and insurer. Each may include a Tier 1 FEMA 452 assessment (discussed 
in more detail in Chapter 2) or equivalent terrorism risk assessment in 
their implementation of due diligence. 

Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment 
Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work 
Budgeting 
8. Define Budget Packaging Funding 
Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 


1.7.2 steP 2 iDentiFY anD iMPLeMent initiaL 
inCReMent integRatiOn OPPORtUnities 

Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment 
Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk 
Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work Budgeting 
8. Define Budget Packaging Funding 
Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 
This step is implemented in the initial redevelopment phase of the facility 
management process. As stated above, the types of redevelopment phase capital 
improvement projects vary, but generally consist of: 
 
Architectural upgrading of entrances, lobbies, and public areas 

Architectural upgrading of facades 
 
Upgrading of the HVAC systems 
 
Environmental and other risk remediation work identified in the due 
diligence process 
 
Upgrading of life safety systems 

The owner should consider using the guidance provided in Chapter 
2 of this manual to identify and implement specific terrorism risk 
reduction increments that can be integrated with these redevelopment 
capital improvements. Detailed information on specific risk reduction 
increments is presented in Chapters 3, 4, and 5. 


1.7.3 steP 3 assess teRRORisM Risk 

Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment 
Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work 
Budgeting 
8. Define Budget Packaging Funding 
Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 

This step is implemented as part of the scheduled and recurring 
assessment activities carried out in the use phase of the facility 
management process. As stated above, some of these assessment activities 
may address the following issues: 

Specific environmental hazards 

Preventive maintenance needs 
 
Asbestos

Structural hazards 

Lead paint 

Fire/life safety 

Lead 

Environmental quality 

Radon 

Energy use/conservation 



User complaints 

Accessibility 
 
Maintenance needs 

Other 

The owner should consider performing a Tier 1 FEMA 452 terrorism 
risk assessment (discussed in more detail in Chapter 2 of this manual) 
or equivalent as appropriate. Particular attention should be paid to the 
following factors: 


Government tenants, such as the U.S. General Services Administration 
or DoD, or government leased facilities that may have specific security 
requirements 
 
Tenant complaints about perceived security vulnerabilities 


1.7.4 steP 4 DeVeLOP a seCURitY MasteR 
PLan 

Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment 
Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work 
Budgeting 
8. Define Budget Packaging Funding 
Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 

This step is implemented as part of the planning phase of the facility 
management process. A security master plan relates to both strategic 
plans and facility plans. A security master plan should be a 3-to 5-year 
plan, based on the goals of the overall organization. It should state the 
vision, goals, and objectives of the security program. The plan should 
also outline the operational security measures, the path for the security 
program to keep pace with the changing threat environment, and 
future initiatives. Further, it should be benchmarked against the security 
programs of similar facilities. 

The security master plan provides the basis for all subsequent steps of the 
incremental terrorism risk reduction program. 

A comprehensive Security Master Plan should: 

Be communicated and disseminated to all levels of management and 
building occupants as appropriate 
 
Be integrated into the facility construction or renovation planning 
 
Be benchmarked or compared to related facilities 
 
Be tested and evaluated 
 
Identify threats/hazards, assets, vulnerabilities, and risks 
 
Establish a security improvement implementation schedule 
 
Establish a security operating and capital budget 
 
Follow regulatory or industry guidelines/standards 

The owner should consider requiring the development of a Security 
Master Plan in accordance with guidance provided in Chapter 5. 

1.7.5 steP 5 PLan inCReMentaL 
ReHaBiLitatiOn FOR sPeCiFiC BUiLDings 

Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment 
Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work Budgeting 
8. Define Budget Packaging Funding Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 

This step is implemented as part of the planning phase of the facility 
management process. 

The owner should consider using the guidance provided in Chapter 2 of 
this manual to identify and implement specific terrorism risk reduction 
measures that can be integrated with planned maintenance and capital 
improvement projects. 

The incremental rehabilitation plan combines information from the 
Security Master Plan (Step 4) and the strategic and facility plans discussed 
in Section 1.5.4, and provides a coherent sequencing of increments. 



1.7.6 steP 6 stage ReHaBiLitatiOn 
inCReMents 

Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work Budgeting 
8. Define Budget Packaging Funding Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 

This step is implemented as part of the planning phase of the facility 
management process, and is closely related to Step 5. 

Consider the staging of increments of terrorism risk reduction on the 
basis of a life-cycle benefit analysis. Figure 1-11 illustrates such a life-
cycle benefit analysis. The three wide arrows represent the benefits 
of single-stage rehabilitation occurring at three points in time: now, 
in 10 years, and in 20 years. Clearly, the largest benefit derives from a 
single-stage rehabilitation done now, and is designated as 100 percent. 
The benefits of single-stage rehabilitation done in the future must be 
discounted and expressed as some percentage lower than 100 percent, as 
represented by the smaller arrows. The stepped portion of the diagram 
represents incremental rehabilitation starting soon and completed in 
four increments over 10 years. The benefits of the future increments 
must also be discounted, and the benefit of the completed incremental 
rehabilitation is therefore expressed as a percentage lower than 100 
percent, but higher than the single-stage rehabilitation in year 10 or 
20. Reducing the overall duration of the incremental rehabilitation will 
increase its benefit, and extending the duration will decrease it. 

Figure 1-11: Life-cycle benefit analysis. 


1.7.7 steP 7 COORDinate WitH tenant WORk 

This step is implemented as part of the planning phase of the facility 
management process, and is closely related to Step 5. 
Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work Budgeting 
8. Define Budget Packaging Funding Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 

In addition to the integration opportunities with maintenance and capital 
improvement work done in Step 5, the owner should consider integrating 
additional increments of terrorism risk reduction with tenant work in 
coordination with the tenants. 

1.7.8 steP 8 DeFine BUDget PaCkaging 

This step is implemented as part of the budgeting phase of the facility 
management process. 
The owner s facility, risk, and financial managers should determine: 
Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 
1. Conduct Due Diligence Terrorism Risk Assessment Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work Budgeting 
8. Define Budget Packaging Funding Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 


Potential losses due to terrorist attack (life, property, business 
interruption) 
 
The owner?s potential liability related to terrorist attacks 
 
The extent of security considerations attendant to government fiscal 
regulations applicable to the owner s organization 
 
The extent of lender-imposed terrorism risk insurance requirements 

The owner?s facility, risk, and financial managers should carefully plan the 
presentation of incremental security enhancement budgets to maximize 
the probability of their being approved, given the financial realities of the 
owner organization. A benefit-cost analysis as initiated in Step 6 can help. 

Concentrating on terrorism risk reduction measures that also reduce 
the risk of damage from natural disasters, and other causes may also be 
useful. 


1.7.9 steP 9 iMPLeMent integRateD 
inCReMentaL ReHaBiLitatiOn PROJeCt 
ManageMent 

Phase Steps of an Incremental Terrorism Risk Reduction Program 
Acquisition 

1. Conduct Due Diligence Terrorism Risk Assessment Redevelopment 
2. Identify and Implement Initial Increment Integration Opportunities 
Use 
3. Assess Terrorism Risk Planning 
4. Develop a Security Master Plan 
5. Plan Incremental Rehabilitation for Specific Buildings 
6. Stage Rehabilitation Increments 
7. Coordinate with Tenant Work Budgeting 
8. Define Budget Packaging Funding Implementation 
9. Implement Integrated Incremental Rehabilitation Project Management 

The implementation of the plans developed in Step 5, consisting of 
selected incremental security rehabilitation measures in combination with 
other building work, may require added attention to project design and 
bid packaging. 

Fully brief or train in-house architects/engineers or outside 
consultants preparing the bid documents on the rationale behind the 
integration of physical protection and strengthening increments with 
the maintenance and capital improvement activities, as presented in 
Chapter 2 of this manual, to ensure that the terrorism risk reduction 
objectives are achieved. 
 
Ensure the continuity of building documentation from the analysis 
and design stages through construction and as-built drawings. 
 
Conduct a pre-bid conference to explain to all prospective bidders 
the terrorism risk reduction objectives and the rationale for their 
selection. 
 
In cases where security rehabilitation increments are to be 
implemented within tenant spaces, whether or not they are integrated 
with other items of tenant work, the tenant work and owner work 
should be well coordinated. 


1.8 teRRORisM Risk assessMent tO teRRORisM Risk ReDUCtiOn 

These two activities, briefly discussed in this chapter as they relate 
to the phases of commercial building facility management, are 
discussed in detail in the Chapter 2. 



Moving from Risk Assessment to Implementation of Incremental Building 
Protection 
2 

The terrorism risk assessment process
described in FEMA 452, Risk Assessment: A
How-To Guide to Mitigate Potential Terrorist
Attacks Against Buildings, helps building owners
to assess major vulnerabilities in a building and
identify mitigation measures to correct such
vulnerabilities. The information generated
by the application of FEMA 452 and by the
methodology provided in this manual are
fundamental for implementing an incremental
security enhancement process for existing
commercial buildings.

[text box]
The mitigation measures generated by
the application of FEMA 452 provide the
starting point for the application of this
document. This document then demonstrates
how a building owner or facility manager
categorizes those mitigation measures into
increments of terrorism risk reduction, and
integrates the increments into ongoing or
planned facility maintenance or capital
improvement projects.
[end text box]


A building owner or facility manager proceeding through the five steps 
of FEMA 452 described in Section 2.1 generates a series of physical 
protection and strengthening measures, as well as operational mitigation 
measures. In moving from a risk assessment to implementation, the 
building owner should check the compatibility of the former (physical 
protection and strengthening), as well as some of the latter (operational), 
with the maintenance and capital improvement plans. A matrix, as shown in 
Section 2.3, should be used to highlight opportunities for integration of 
specific mitigation options with specific maintenance or capital improvement 
activities. 

2.1 Risk Assessment Process 
the risk assessment process described in FEMA 452 is based on five 
critical steps (Figure 2-1). These critical steps identify the best and 
most cost-effective terrorism mitigation measures for a buildings 
unique security needs. 

Conducting a threat assessment to identify, define, and quantify the 
threats or hazards is the first step of the risk assessment process. For 
terrorism, the threats are aggressors (people or groups) that are known to 
exist and that have the capability and a history of using hostile actions, or 
that have expressed intentions for using hostile actions against potential 
targets. Current credible information on targeting activity (surveillance of 
potential targets) or indications of preparation for terrorist acts may be 
available for these aggressors. 

Figure 2-1: Risk assessment process model. 

The second step of the risk assessment process is to identify the 
consequences of the loss of a building that needs to be protected from 
terrorist attack. Consequences relate to the criticality of the building in 
terms of the importance of the building operation to the owner and the 
locality, and can be defined as a degree of debilitation that would be 
caused by its destruction. This assessment of consequences can be applied 
to the entire building or significant portions of a very large building. It 
can also refer to a resource of value requiring protection. Consequences can 
be tangible (i.e., loss of buildings, facilities, equipment activities, 
operations, and information) or intangible (e.g., loss of processes or a 
companys reputation). 

As explained in FEMA 452, after assessing consequences, the third 
step is to conduct a vulnerability assessment. A vulnerability assessment 
evaluates the potential vulnerability of the critical assets against a broad 
range of identified threats and natural hazards. By itself, the vulnerability 
assessment provides a basis for determining mitigation measures for protection 
of the building and its content. The assessment is a bridge in the methodology 
among threat/hazard, consequences, and the resultant level of risk. 

The fourth step of the process is the risk assessment. The risk assessment 
analyzes the likelihood or probability of the threat or natural hazard 
occurring and the consequences of the occurrence. Thus, a very high likelihood 
of occurrence with very small consequences may require simple low cost 
mitigation measures, but a very low likelihood of 
occurrence with very serious consequences may require more costly and 
complex mitigation measures. The risk assessment should provide a 
relative risk profile. High-risk combinations of assets against associated 
threats, with the identified vulnerability, allow prioritization of resources 
to implement mitigation measures. 

The fifth and final step is to consider mitigation options that are directly 
associated with, and responsive to, the major risks identified during Step 4. 
From Step 5, decisions can be made as to where to minimize the risks and how 
to accomplish that over time. 

2.1.1 Levels OF Vulnerability assessment 

FEMA 452 provides guidance in conducting varied levels of assessments, 
ranging from screening level assessments to in-depth assessments. As 
stated in FEMA 452, the level of assessment for a given building is 
dependent upon a number of factors such as potential threat, type 
of building, location, type of construction, number of occupants, 
economic life, and other owner specific concerns and available economic 
resources. FEMA 452 defines a three-tier assessment process as follows: 

Tier 1. A Tier 1 assessment is a 70 percent assessment. It can typically be 
conducted by one or two experienced assessment professionals in approximately 
two days. A Tier 1 assessment will likely be sufficient for the majority of 
commercial buildings and other non-critical facilities and infrastructure. 

Tier 2. A Tier 2 assessment is a 90 percent assessment. It typically 
requires three to five assessment specialists, can be completed in 3 to 5 
days, and requires key building staff participation. A Tier 2 assessment 
is likely to be sufficient for most high-risk buildings such as iconic 
commercial buildings, government facilities, schools, hospitals, and other 
high-value designated infrastructure assets. 

Tier 3. A Tier 3 assessment is a detailed evaluation of the building using 
blast, weapons of mass destruction (WMD), earthquake, flood, and high wind 
models to determine building response, survivability, and recovery, and the 
development of mitigation options. The assessment team is not defined for this 
tier; however, it could be composed of 8 to 12 people. Modeling and analysis 
can often take several days or weeks and is typically performed for high value 
and critical infrastructure assets. 

2.1.2 the Building Vulnerability assessment Checklist 

FEMA 452 includes a Building Vulnerability Assessment Checklist, 
covering explosives, CBR, earthquakes, floods, and high-wind hazards. 
The checklist can be used to collect and report information related to the 
building. It compiles many best practices, based on the latest technologies 
and scientific research, to consider during the design of a new building or 
renovation of an existing building. 

The vulnerability assessment step is supported by the Building 
Vulnerability Assessment Checklist (FEMA 452, Appendix A), which is 
organized into 13 sections corresponding to building subsystems: 

1. Site
2. Architectural
3. Structural Systems
4. Building Envelope
5. Utility Systems
6. Mechanical Systems
7. Plumbing and Gas Systems
8. Electrical Systems
9. Fire Alarm Systems
10. Communications and IT Systems
11. Equipment Operations and Maintenance
12. Security Systems
13. Security Master Plan

The 13 sections of the Building Vulnerability Assessment Checklist 
provide a framework for the categorization of incremental measures of 
terrorism risk reduction discussed in the following sections. 

[text box]
To support the building assessment
process, a Risk Assessment
Database has been developed
as a companion tool to FEMA
452. The database is a standalone
application with several
functions: import files and folders;
display digital photos, emergency
plans, and digital floor plans; and
provide specific GIS tools. The
database can be used to collect
and report information related to
the building.
[end text box]


2.2 scheduling increments: 
Physical Protection and strengthening Measures and Operational (Protective and 
Control) Measures 

Once identified, the terrorism risk reduction improvements 
should be considered in relation to the owners ongoing facility 
planning for maintenance and capital improvements (discussed 
in Section 2.3). Physical protection and strengthening measures and 
some operational measures can then be integrated with maintenance 
and capital improvements using this document, and can be scheduled for 
implementation. 

2.2.1 Physical Protection and strengthening Measures 

The increments of physical protections measures listed on the vertical 
axes of the integration matrices 1 and 2 in Section 2.3 are presented 
as an example of measures that might be generated by the FEMA 452 
process or others and implemented using this manual. The specific 
measures included in the matrices were generated for this manual and 
are discussed in Chapters 3, 4, and 5. Where applicable, the references in 
parentheses following items in the list refer to the respective discussions in 
Chapters 3, 4, and 5. The protection measures are presented in the order of 
the 13 sections of the Building Vulnerability Assessment 
Checklist in Appendix A of FEMA 452. 

2.2.2 Operational Measures 

The list of incremental operational measures is presented in Chapter 5, 
Section 5.11 as an example of measures that might be generated by the 
FEMA 452 process or others and implemented using this manual. The 
specific measures included in the matrices were generated for this manual 
and are discussed in Chapters 4 and 5. Some of these measures include 
physical elements and are also included in the list that comprises the 
vertical axes of the integration matrices in Section 2.3. Where applicable, 
the references in parentheses following items in both lists (Section 2.3 and 
Section 5.11) refer to the applicable discussions in Chapters 4 and 5. The 
measures are presented in the order of the 13 sections of the Building 
Vulnerability Assessment Checklist in Appendix A of FEMA 452. 

2.3 identifying integration Opportunities FOR incremental Building Protection 

Typical maintenance and capital improvement projects in commercial buildings 
fall into two categories: 

Maintenance and capital improvements that are common to all 
four types of commercial buildingsoffice, retail, and multifamily 
apartment buildings, and hotels. 

Maintenance and capital improvements specific and unique to each of 
the four types of commercial buildings. 

These categories may also vary by building classification (A, B, or C). 

The following categorizations of maintenance and capital improvements are 
typical and reflect groupings of building elements, administrative and 
funding categories, tenant versus public spaces, or other parameters. 
Owners can substitute their own categories. 

Common categories of maintenance and capital improvement projects: 

1. Roofing maintenance and repair/reroofing 
2. Exterior wall and window maintenance/faade modernization 
3. Fire and life safety improvements 
4. Public area modernization (Retail: mall public areas; Hotels: 
public and service areas) 
5. Underfloor and basement maintenance and repair 
6. HVAC upgrade and energy conservation 
7. Hazardous materials abatement 
8. Landscaping and site work 
Occupancy-specific categories of maintenance and capital improvement 
projects: 

Office Buildings: 

1. New technology accommodations 
2. Tenant alterations and improvements 

Retail Buildings: 
1. Retail area modernization 

Multifamily Apartment Buildings: 
1. Kitchen and bathroom modernization 

Hotels and Motels: 
1. Guestroom finishing, furniture, and equipment (FF&E) 
2. Public area FF&E 

Both of these respective categories are used as the horizontal axes of the 
integration matrices presented on the following pages. 

How to Use the Matrices 

In order to identify integration opportunities, a building owner should 
follow these three steps: 

1. Identify the column of the planned maintenance or capital 
improvement. 
2. Identify the physical increments of building protection with a 
corresponding check mark in the column. 
3. Consider integration of the physical increments with the planned 
maintenance or capital improvement activities. 

Matrix 1: Integration Opportunities for Common Categories 
of Maintenance and Capital Improvement Projects 

Matrix 2: Integration Opportunities for Occupancy-Specific Categories 
of Maintenance and Capital Improvement Projects 


FEMA 459 / April 2008 

Risk Management Series 

Incremental Protection for Existing Commercial Buildings from Terrorist 
Attack: Providing Protection to People and Buildings



CHAPTER 3 PRINCIPLES OF DESIGN FOR RISK REDUCTION RELATED TO BLASTS 

Most commercial buildings in the United States have not been designed and 
constructed to resist blasts. Therefore, the results of a FEMA 452 risk 
assessment may yield many high-risk scores to explosive blasts. New 
technologies and mitigation options are available to incrementally reduce the 
consequences of explosive blasts. footnote 1

[begin footnote 1]
1. Much of the content for this chapter has been drawn from the articles 
Designing to Resist Explosive Threats and Retrofits to Resist Explosive 
Threats by Robert Smilowitz. These documents were originally prepared for 
the National Institute of Building Sciences in 2005 and later published on 
their Web-based portal, Whole Building Design Guide (www.wbdg.org), as a 
resource for building professionals. 
[End footnote 1]

[Begin text box]
FEMA 452, Risk Assessment: A How-To Guide to Mitigate Potential Terrorist 
Attacks Against Buildings, January 2005, outlines methods for identifying the 
critical assets and functions within buildings, determining the threats to 
those assets, and assessing the vulnerabilities associated with those 
threats. The Guide provides a means to assess the risk and make risk-informed 
decisions to reduce vulnerability. The Guide also discusses methods to reduce 
physical damage to structural and non- structural components of buildings and 
related infrastructure and reducing resultant casualties that may occur 
during an explosive or CBR attack. Finally, the Guide leads the reader 
through a process for conducting a risk assessment and selecting mitigation 
options. 
[End text box]

Some existing buildings may require retrofits for explosive threats if 
changes in purpose, occupancy, or world events make them more likely to be 
targets of a terrorist attack. Similarly, prudent facility managers should 
also consider whether nearby buildings are likely targets for terrorist 
attack. Conducting a risk assessment is the first step in determining the 
need to upgrade a conventionally designed building to protect its occupants 
and assets. The risk assessment identifies the maximum credible threats and 
the associated hazards based on the site conditions, neighboring properties, 
building layout, access control, structural framing, and facade components. 

The effectiveness of the upgrades depends to a great extent on the structural 
details of the building and the acceptability of the aesthetic and functional 
impacts. For example, historic preservation requirements may limit secure 
design alternatives that would otherwise be considered appropriate. The cost 
of protective design and the impact of this protection on the property may be 
minimized using advanced analytical methods. These methods, developed over 
years of explosive testing and numerical simulation, enable the design team 
to focus resources on portions of the structure that are most likely to 
sustain damage and minimize materials required to mitigate these hazards. The 
protective measures that may offer the most benefits from these methods 
include the design of defensible perimeters, the design of protective facade 
systems, the hardening of structures to resist the effects of progressive 
collapse, the retrofit of existing structures, and the protection of non-
structural components. The following sections describe retrofit upgrades that 
may be used to either reduce the hazard of debris impact or increase the load 
resistance of the structure. 

This chapter identifies the protective measures that may be applied to the 
building perimeter, structure, and envelope, and non-structural systems 
within the incremental framework. Starting from the exterior of the building 
and working inward, these distinct protective upgrade projects may be 
combined with building maintenance and capital improvement projects. For 
buildings perceived as vulnerable to attack by virtue of their iconic nature 
or controversial occupancy, perimeter protection projects or column hardening 
may be beneficial. For other buildings, which may be in the vicinity of a 
likely target, perimeter protection and structural hardening will not reduce 
the risk of collateral damage. A protective facade upgrade makes more sense 
for these buildings. The incremental approach allows building owners to 
identify the best use of limited resources and combine these protective 
measures with other modernization projects that may increase the value of 
their property. Following a brief description of significant terrorist 
attacks against commercial properties, this chapter explores protective 
measures for: 

. Building perimeters 
. Building structures 
. Building envelopes 
. Non-structural systems 


3.1 SELECTED EXAMPLES OF TERRORIST ATTACKS ON BUILDINGS 

the following sections describe past terrorist attacks on buildings and the 
extent of collateral damage to neighboring structures.footnote 2 The 
approximate dollar values for damages correspond to the time of the incident. 
These descriptions of blast damage inform the methods of assessing building 
vulnerabilities described in FEMA 452 and the physical and operational 
enhancements to address vulnerabilities to explosive blasts described in this 
document. 

[Begin footnote 2] 
These descriptions were first published in 2007 as part of FEMA 430, Site and 
Urban Design for Security. 
[End footnote 2]


3.1.1 BALTIC EXCHANGE, CITY OF LONDON, APRIL 1992 footnote 3

[Begin footnote 3]
3. SOURCES: Jonathan Bell, The Morning News: Letters from London: Raising 
the Game; Peter Dorsman, Peak Talk, The Baltic Exchange Bomb, from 
www.peaktalk.com/archives/000143.php; London Destruction: 
Baltic Exchange, from http://us.geocities.com/londondestruction/baltic.html; 
Leslie Hutchings, Discussion Forum, from 
www.sapling.info/discussionforum/postings/1104.shtml. 
[end footnote 3]

Founded in the mid-eighteenth century, the Baltic Exchange is a United 
Kingdom company that operates the premier global marketplace for shipbrokers, 
ship owners, and charterers. It occupied a historic London building built in 
1903. 

In April 1992, at 9:20 p.m., the offices of the Baltic Exchange at 30 St. 
Mary Axe, London were virtually destroyed in an Irish Republican Army (IRA) 
bomb attack. A small truck carrying the explosives pulled up to the building 
on St. Mary Axe, a narrow street in the heart of Londons financial district. 
The attack represents the first use of a large fertilizer-based homemade 
explosive device: the bombs power was enhanced by a Semtex-based detonating 
cord wrapped around the explosives. Although most of the office workers had 
gone home, the bomb killed three people, all by flying glass, and injured 91. 
The damage was estimated at about $1.2 billion. 

3.1.2 WORLD TRADE CENTER, footnote 4 NEW YORK CITY, FEBRUARY 1993 

[Begin footnote 4]
4. SOURCES: ADL Law Enforcement Agency Resource Network; CNN, WTCs owners 
found negligent in 1993 bombing; The 1993 Bombing: the First Attack on the 
World Trade Center, from http://911research.wtc7. 
net; John V. Parachini, February 1993 Bombing of the World Trade Center in 
New York City, CNS Center for Nonproliferation Studies, from 
http://cns.miis.edu/pubs/reports/wtc93.htm; J. Dwyer et al., Two Seconds 
Under the World: Terror Comes to America  The Conspiracy Behind the World 
Trade Center Bombing, Crown Publishers, New York, 1994. 
[End footnote 4]

On Friday, February 26, 1993, at 12:18 p.m. a large explosion ripped through 
the public parking garage of the World Trade Center. The explosion caused six 
deaths, more than 1,000 injuries, and $300 million in property damage. 

The explosive device, a 1,500-pound urea-nitrate bomb (equivalent to about 
900 pounds of trinitrotoluene [TNT]), was detonated in a rented Ford van 
parked in the basement parking garage using a timer. The explosion created a 
200-foot by 100-foot crater several stories deep (Figure 3-1). The power and 
emergency systems of the World Trade Center were destroyed. Most of the 
injuries were due to smoke inhalation. 

[Begin Figure]
Figure 3-1 is a photo showing damage in WTC garage caused by the 1993 bomb 
attack. Source: Corbis.
[End Figure]


3.1.3 BISHOPSGATE,FOOTNOTE 5 CITY OF LONDON, APRIL 1993 

[Begin footnote 5]
5. SOURCES: BBC On This Day, 1993, IRA bomb devastates City of London; 
Jonathan Liebenau, London School of Economics, Information and 
Communications Disaster Recovery. Principles Of Design For Risk Reduction 
Related To Blasts 
[End footnote 5]

A bomb hidden in the back of a large truck exploded in a narrow street, 
killing one person and injuring more than 40. The explosive was a homemade 
device using about 1 ton of fertilizer and was similar to the bomb that 
devastated the nearby Baltic Exchange (Section 3.1.1). The explosion shook 
buildings and shattered hundreds of windows, sending glass showering down 
into the streets below. A medieval church, St. Ethelburgas, collapsed. 
Another church and the Liverpool Street underground station were also 
destroyed. 

The damage was estimated at more than $1.5 billion. The Baltic Exchange, just 
having reopened following the completion of repairs from the 1992 bombing, 
was again damaged. Huge insurance payouts contributed to a crisis in the 
insurance industry, including the near financial collapse of the worlds 
leading insurance market, Lloyds of London. 


3.1.4 TOWN CENTER, MANCHESTER, footnote 6 ENGLAND, JUNE 1996 

[Begin Footnote 6]
6. SOURCES: John Moss, Manchester 2004, The Manchester Bombing, June 1996, 
from www.manchester 2002-uk.com/buildings/bombing.html; BBC On This Day, 
1996, Huge explosion rocks central Manchester. 
[End footnote 6]

On June 15, 1996, at a peak shopping time on Fathers Day, a 3,000pound IRA 
bomb (equivalent to about 1,800 pounds of TNT) exploded in Manchester, the 
second largest city in the United Kingdom. The explosion injured more than 
200 people and ripped into the fabric of the citys main shopping center 
(Figure 3-2). 

[Begin figure]
Figure 3-2 is a photo showing Manchester shopping center damage. 
Source: Corbis 
[End figure]

Several telephone warnings about an hour before the blast and the 
subsequent police evacuations averted major casualties. Shoppers were 
evacuated from the Marks and Spencer Department Store at the center of 
the site, outside which the truck bomb was parked. An army bomb squad 
employing a robotic anti-bomb device was checking an illegally parked 
van, which had been recorded by several closed-circuit security cameras in 
the city, when the bomb exploded. 

Most injuries were sustained from falling glass and building debris. The 
main railroad stations were closed for several hours, and the city center 
was sealed off. 

An estimated 450,000 square feet of retail space and about 200,000 
square feet of office space required reconstruction. A master plan for 
redevelopment of the city center was quickly developed. An international 
urban design competition launched one month after the bombing provided a 
cohesive plan for rebuilding. After 4 years, the devastated zone was 
completely restored. Marks and Spencer rebuilt on its original site, with its 
largest store in the world (Figure 3-3). 

[begin figure]
Figure 3-3 is a photo showing New Marks and Spencer store, Manchester. 
Source: Chris Arnold 


3.2 PERFORMANCE STANDARDS 

Based on such recent experience of terrorism blast damage in commercial 
buildings, methods of analysis and design have been developed to reduce 
damage in existing buildings. These methods are discussed below. 

A buildings performance in response to blast loadings must be evaluated 
whether it is a likely target or close enough to a likely target to suffer 
collateral damage. The effects of a near contact detonation, such as a 
satchel threat placed in contact with a column or a vehicle-transported 
explosive near the structure, are significantly different from the effects of 
a distant detonation. Different analytical methods are required to evaluate 
the likely performance of building systems in response to varied intensities 
of blast loading. 

Appropriate analytical methods are needed to demonstrate compliance with 
blast criteria or performance specifications established by agencies, such as 
the General Services Administration, the U.S. Department of 


State, and others. Risk-based performance criteria must be established for 
each building in order to define the protective objectives. Continuity of 
services objectives require performance criteria that are significantly more 
severe than those for a life safety objective. Consequently, establishing the 
design objectives at the onset is important. 

[begin text box]
DYNAMIC ANALYSIS OF BUILDINGS 

The performance of building systems and components in response to blast 
loading may be evaluated numerically using the principals of Structural 
Dynamics. These methods represent the inert a, the stiffness, and the 
strength of the dynamic system using a combination of nonlinear springs and 
masses. Simple Single Degree of Freedom (SDOF) models are appropriate for 
components on which the loading s un form and the response s well character 
zed by the nonlinear spring. More complex mater al behavior, dynamic loading 
effects, and geometric nonlinear ties require more complex Multi-Degree of 
Freedom (MDOF) models. The most complex structural systems must be analyzed 
using Finite Element Methods (FEM), which determines the nonlinear dynamic 
response using an design are to fully utilize the explicit formulation of the 
equations of mot on. Each level of analytical complexity requires 
successively more experience and expert se on the part of the blast response 
analyst.
[End text box]

Furthermore, many of these performance criteria require that the building 
system be a balanced design. The objectives of balanced load capacity of all 
the materials, maximize the potential energy dissipated due to deformation, 
and manage the failure mechanisms. These objectives can be accomplished by 
ensuring a controlled sequence of failure. The expected performance of the 
building systems in response to either a targeted attack or collateral damage 
will determine the level of protection required, the sizing of the structural 
and nonstructural members, and the design of the connections between the 
different building components. 

The behavior of structural materials, such as steel and aluminum, in response 
to explosive loading has been the subject of intensive investigation by the 
governments of the United Kingdom, Israel, and the United States of America. 
Some structural materials behave very differently when subjected to high 
strain rate loading than they do under static conditions. Furthermore, the 
inelastic deformation of structural members depends on their section 
properties, shape functions, and extent of deformation. For compound sections 
composed of different pieces and materials, transformed section properties 
may be used to characterize an equivalent material and a combined or 
composite section property may be used to represent its structural 
resistance. Care must be taken to calculate composite section properties when 
strain compatibility between components can be justified and combined section 
properties 
when deformation compatibility between components is achieved. 


[Begin text box]
The performance of building systems n response to explosive loading s 
highly dynamic, highly inelastic, and highly interactive. by controlling the 
flexibility and resulting deformations, the structural or facade component 
may be designed to dissipate considerable amounts of blast energy. The 
phasing of the different component responses and the energy that is 
dissipated through inelastic deformation must be carefully represented in 
order to accurately determine the behavior of the components. The SDOF 
model approach commonly used to analyze individual components is 

likely to produce conservative designs. An accurate representation of the 
structural system requires a complex MDOF model. These MDOF models 
may be developed using appropriate inelastic Finite Element software in 
which an explicit formulation of the equations of mot on s solved. 

. Advanced analytical methods provide the most authentic 
representation of the systems ability to resist the dynamic blast 
loading and will produce the most cost-effective retrofits wherever 
the strength of the system s being evaluated. 

. Simplified analytical methods and empirical relations are sufficient 
for debris m t gating upgrades, such as a daylight application of 
fragment retention film or blast resistant glazing fabricated with 
laminated glass. 

. Approx mate methods, such as the ASTM F 2248-03, Standard 
Practice for Specifying an Equivalent 3-Second Duration Design 
Loading for Blast Resistant Glazing Fabricated with Laminated 
Glass, do not require advanced analytical methods. Although this 
approximate approach does not quantify the improved behavior 
of glass n response to blast loading t provides a design load 
suitable for sizing blast resistant glazing comprised of laminated 
glass or insulating glass fabricated with laminated glass (ASTM, 
2003). 


3.3 SITE INCREMENTAL UPGRADES: PERIMETER PROTECTION 

The risk analysis will help facility owners determine whether their 
building is a likely target or close enough to a likely target to suffer 
collateral damage. Perimeter protection only improves the performance of 
buildings that are targets of explosive attacks and provides no reduction in 
hazard if the building is vulnerable to collateral damage. However, 
characteristics of explosives, such as the charge weight, the efficiency of 
the chemical reaction, and the source location, that would likely be used in 
such attacks cannot be reliably predicted. Given these uncertainties, the 
most effective means of protecting a structure is to keep the bomb as far 
away from the building as possible by maximizing the standoff distance. 
Facility managers often respond to world events by constructing a perimeter 
around their building even before they evaluate the risk to their building. 
This approach presumes the facility will be the target of a terrorist attack 
and is intended to either discourage the attacking vehicle or to prevent it 
from driving up against the structure. Although a temporary incremental 
rehabilitation measure may be an appropriate strategy until a risk assessment 
can be performed, a permanent perimeter protection installation requires an 
intensive study of traffic patterns and subgrade conditions. 

To guarantee the maximum standoff distance between unscreened vehicles and 
the structure and to resist a moving vehicle attack, anti-ram barriers must 
be placed around the entire perimeter of the building. For urban buildings, 
the defensible perimeter is most effectively located as close to the curb as 
possible in order to maximize the available standoff distances. More standoff 
distance is typically available at suburban and rural sites and there may be 
more options for locating the defensible perimeter without diminishing 
effectiveness. The site conditions determine the maximum vehicle speeds 
attainable, and thus the kinetic energy that must be resisted. Both the 
impact-protective device (bollard or barrier) and its foundation must be 
designed to resist the maximum load (see Figure 3-4). Permanent barriers, 
especially ones rated for high impact levels, generally have very large, deep 
foundations. Placement of these foundations is difficult in urban areas 
because underground transportation facilities, building vaults, and utilities 
are often densely packed, and their locations may not be documented correctly 
or at all. Surveys and testing must be performed before construction begins 
to fully understand the feasibility and extent of these complications and to 
develop an appropriate design. 

[Begin Figure]
Figure 3-4 shows barriers and bollards. 
[end figure

Conversely, if design restrictions limit the capacity of the impact-
protective device or its foundation, then site restrictions will be required 
to limit the maximum speeds attainable. Speed calming devices may be 
installed to control the speed of oncoming vehicles. Furthermore, public 
parking abutting the building must be secured or eliminated, and street 
parking should not be permitted adjacent to the building. Removing one lane 
of traffic and turning it into an extended sidewalk or plaza can add 
additional standoff distance. However, the practical benefit of increasing 
the standoff depends on the charge weight. If the charge weight is small, 
this measure will significantly reduce the forces to a more manageable level. 
If the threat is a large charge weight, the blast forces may overwhelm the 
structure despite the addition of several feet to the standoff distance, and 
the measure may not significantly improve survivability of the occupants or 
the structure. 

Entrances to parking garages and loading docks require operable barriers 
so that security personnel have the means to deny access to unauthorized 
vehicles following an inspection of their credentials or the contents of 
their cargo space. These operable barriers must be located to provide 
security personnel an effective means to inspect vehicles while minimizing 
the impact of queues on surrounding traffic patterns. Furthermore, the 
surrounding structure must be designed to accept the large dynamic forces 
that may be transferred upon impact. 

3.4 INCREMENTAL BUILDING REHABILITATION MEASURES 

3.4.1 BUILDING ENVELOPE 

One of the most formidable tasks facing property owners is the upgrade of an 
existing facade to resist blasts. Blast pressures engulf a structure, and 
glass damage can occur as far as a mile from a sizable vehicle detonation. 
Glass damage from the terrorist bombing in Oklahoma City was reported up to 
4,000 feet away from the Murrah Building (see Figure 3-5). Because the 
intensity of blast loads vary as a function of height and exposure relative 
to the point of detonation, facility managers may be able to prioritize 
upgrades to take advantage of site-specific features. This is particularly 
true if another nearby building is identified to be the likely target of the 
attack and the directionality of the 
blast waves produce reflected pressures on some surfaces and not others. 
Similarly, results of a blast analysis may permit upper floors to be treated 
differently from lower floors. 

[Begin figure]
Figure 3-5 is an illustration showing locations of the Murrah Building and 
other damaged structures.
[End figure]

Contractors rarely have access to the entire facade from within the building 
unless the building is undergoing a major modernization. But when these 
opportunities do arise, a significant level of protection can be introduced 
into the existing structure. This is particularly true when the design team 
uses state-of-the-art technologies. With conventional approaches, all glazing 
is treated as if it were supported in rigid openings; however, the actual 
performance of flexible facade systems in response to blast loading may be 
far more forgiving. An accurate representation of the glazing response to 
blast loading requires proper understanding of the facades flexibility. The 
full load-bearing capacity of all the components may then be realized through 
the appropriate detailing of the mullions, connections, and anchorages. Over-
design of glass and its support structure can lead to wasted money and in 
some cases premature failure. 

Since the retrofit of existing structures is often hampered by insufficient 
information about the structure and the presence of brittle materials, 
innovative energy-absorbing retrofit systems may provide the best protection 
for these aging structures. Although difficult to quantify by simplified 
analytical approaches, these energy absorbing systems have been demonstrated 
to transfer reduced forces to the surrounding structure. Once the decision to 
upgrade a facade is made, advanced analytical methods can be used to enhance 
blast resistance at a minimum cost. 

The increased mass of precast panels and masonry walls make them more 
vulnerable to greater intensity blast pressures than glazed facades. The 
strength of unreinforced masonry (URM) or lightly reinforced precast 
panels may be increased with the adhesion of fiber reinforcement to 
the inner surface, and debris may be restrained with the application of 
an elastopolymer; however, the connection details typically present the 
greatest difficulty for new construction and for incremental rehabilitation 
measures. The anchorages of precast concrete panels must develop the panels 
ultimate capacity, in response to direct loading and rebound, in order to 
develop the full blast resistance of the material. Similarly, the anchorage 
of grouted and reinforced masonry walls must be designed to take full 
advantage of the materials strength. Debris catch systems, such as 
geotextile fabrics and steel stud walls, may be installed interior to the 
precast panels and masonry walls if the reinforcement is insufficient and the 
anchorages are inaccessible. 

3.4.2 FRAGMENT RETENTION FILM 

Fragment retention film, also commonly known as shatter-resistant 
window film or security film, is a laminate used to improve post-failure 
performance of existing windows. Applied to the interior face of glass, 
fragment retention film holds the fragments of broken glass together in one 
sheet, thus reducing the projectile hazard of flying glass fragments. A more 
appropriate name for fragment retention film would be fragment reduction 
film, since the methodology behind this hazard mitigation technique focuses 
on retaining glass fragments resulting from blast overpressures. 

Most fragment retention films are made from polyester-based materials 
and coated with adhesives. Clear and tinted fragment retention films are 
available. Clear film has minimal effects on the optical characteristics of 
the glass; tinted film can increase the effectiveness of existing heating/ 
cooling systems, while also providing a variety of aesthetic and optical 
enhancements. Most films are designed with solar inhibitors to screen out 
ultraviolet (UV) rays, though over time the UV absorption damages the films 
adhesive and degrades its effectiveness. 

Film is packaged on rolls in widths as small as 24 inches and as large as 72 
inches, depending on the manufacturer. Some manufacturers laminate 
multiple layers of film together to enhance performance. Whether one-ply or 
multi-ply, the overall film thickness can range from 2 to 15 mils. 
According to some government criteria (and verified by published test 
results), a 7-mil thick fragment retention security film, or specially 
manufactured 4-mil thick film, is considered to be the minimum thickness 
required to provide effective response to blast loads. 

There are three types of fragment retention film installation methods. 
Each of the methods is capable of resisting different intensities of blast 
pressure, with the daylighting installation providing the lowest level of 
protection and the mechanically anchored installation providing the highest 
level of protection. Therefore, the selected installation method for 
incremental rehabilitation should be based on the required level of 
protection. For example, the reduction of fragment hazard in response to 
collateral damage may permit the use of the least invasive installations. The 
different installation methods are: 

. Dry-Glazed Installation 
. Wet-Glazed Installation 
. Mechanically Anchored Installation 

Dry-Glazed Installation. The application of security film must, at a 
minimum, cover the clear area of the window (i.e., the portion of the 
glass unobstructed by the frame). This minimum application to the 
exposed glass without any means of attachment or capture within the 
frame, termed daylighting installation, is commonly used for retrofitting 
windows. Application of the film to the edge of the glass panel where it 
would cover the glass within the bite is called an edge-to-edge installation. 
Other methods of application may improve film performance and further reduce 
hazards but are typically more expensive to install, especially in retrofits. 


Energy absorbing catch systems, used in conjunction with a daylight 
application of fragment retention film, is another mechanism for 
retaining and reducing debris hazards. Cables spanning the window 
will impede the flight of filmed glass and absorb a considerable amount 
of energy upon impact. These cable catch systems are demonstrated, 
through explosive testing, to be more efficient and effective than the 
more rigid catch bar systems described below. 

Wet-Glazed Installation. The wet-glazed installation is a method in which 
the film is positively attached to the frame using a high-strength, liquid 
sealant, such as silicone. Frequently used for field retrofits, the method 
allows the flexible frame to deform slightly, reducing glass fragments 
entering the building and offering more protection than the dry-glazed 
installation. The wet-glazed installation system is more costly than the dry-
glazed installation method, but is less expensive than the mechanically 
anchored/attached installation method described below. 

Mechanically Anchored/Attached Installation. Fragment retention film is 
most effective when it is used in conjunction with a blast-tested anchorage 
system. While a film may be effective in keeping glass fragments together, it 
may not be particularly effective in retaining the glass in the frame. 
Securing the film to the frame with a mechanically connected anchorage system 
further reduces the likelihood of the glazing system exiting the frame. 
Mechanical anchorage systems employ screws and/or batten strips to attach the 
film to the frame along 2 or 4 sides. Because additional framework is 
necessary, the mechanical attachment method can be less aesthetically 
pleasing than the wet-glazed installation system. 

All application and attachment methods can be installed on site in either 
steel or aluminum frames. While some mechanically attached systems may 
be used for a wide variety of windows, others are designed for a particular 
type of window frame. Certain types of window frames may require a custom-
fabricated anchorage system. 

In addition to considering the various methods of installation, the 
designer must consider the thickness of the film and the task of 
positioning the film on the glass. A lighter weight or thinner film eases 
installation. Water used to aid in positioning the film during application 
must be thoroughly extruded, as the film is not very permeable and moisture 
that does not dry will prevent the development of the full adhesive bond 
strength. Fragment retention film should be carefully selected for its 
physical, optical, and thermal characteristics, with special consideration 
given to the adhesive used, the window thickness, and the window area. Window 
frame systems must also be capable of transferring the load collected by the 
glazing system. Corner-welded frames are preferred over frames constructed of 
individual components. A schematic of this mitigation measure is shown in 
Figure 3-6. 

[Begin figure]
Figure 3-6 is an illustration showing mechanically attached fragment 
retention film. 


3.4.3 LAMINATED GLASS

Laminated glass consists of two or more pieces of glass permanently 
bonded together by a tough plastic interlayer made of polyvinyl butyral 
(PVB) resin. Once sealed together, the glass sandwich behaves as a single 
unit. Annealed, heat strengthened, tempered glass or polycarbonate 
glazing can be mixed and matched between layers of laminated glass 
in order to design the most effective lite for a given application. When 
fractured, fragments of laminated glass tend to adhere to the PVB 
interlayer instead of falling freely and potentially causing injury. 

Laminated glass usually lasts as long as ordinary glass if it is not broken 
or damaged. The correct installation of laminated glass is very important to 
ensure long life. Manufacturers typically recommend installation of laminated 
glass on setting blocks that are at least 6 inches long and placed at the 
quarter points of the pane. Architectural details should incorporate a weep 
system for exterior glazing systems. Regardless of the degree of protection 
required, laminated glass needs to be installed with a proper sealant to 
ensure that no water comes in contact with the edges of the glass. The 
sealant supplier should verify that the sealant and PVB interlayer are 
compatible. Generic sealants shown to be compatible with PVB are the 
polysulfides, silicones, butyl or polybutene tapes, and polyurethanes. 
Minimum face and edge clearance should be provided as required by the 
manufacturer. Field cutting should be minimized in butt glazing installations 
to minimize edge defects. Glazing guidelines, such as those presented in the 
Glass Association of North America (formerly Flat Glass Marketing 
Association) Glazing Manual should be followed to avoid installation 
problems. Typical allowances for glass, metal, and erection tolerance, 
expansion, and contraction should be made. 

3.4.4 BLAST CURTAINS 

Blast curtains (see Figure 3-7) are attached to the interior frame of a 
window opening and essentially catch the glass fragments produced by 
a blast wave. The debris is then deposited on the floor at the base of 
the window. The use of these curtains does not eliminate the possibility 
of glass fragments penetrating the interior of the occupied space, but 
instead limits the travel distance of the airborne debris. Overall, the 
hazard level to occupants is significantly reduced by the installation of 
blast curtains. However, a person sitting directly adjacent to a window 
outfitted with a blast curtain may still be injured by shards of glass in the 
event of an explosion. 

[Begin figure]
Figure 3-7 is a photo of blast curtains. 

Blast curtains are made from a variety of materials, including a warp 
knit fabric or a polyethylene fiber. The fiber can be woven into a panel 
as thin as 0.029 inch that weighs less than 1.5 ounces per square foot. 
This fact dispels the myth that blast curtains are heavy sheets of lead that 
completely obstruct a window opening and eliminate all natural light 
from the interior of a protected building. 

The main components of any blast curtain system are the curtains 
themselves, the mechanism by which the curtain is attached to the 
window frame, and either a trough or another retaining mechanism at 
the base of the window to hold the excess curtain material. Blast curtains, 
with curtain rod attachment and sill trough, differ largely from one 
manufacturer to the next. The curtain fabric, material properties, method of 
attachment, and manner in which they operate also vary, providing many 
options within the overall classification of blast curtains, which makes 
blast curtains applicable in many situations. 

As shown in Figure 3-8, blast curtains differ from standard curtains in 
that they do not open and close in the typical manner. Blast curtains are 
designed to remain in a closed position at all times. The curtain may 
be pulled away from the window to allow for cleaning, blind or shade 
operation, or occupant egress in the case of fire. However, the curtains 
can be rendered ineffective if the building occupants do not use them 
correctly by pulling them away from the glazing. The color and openness 
factor of the fabric contributes to the amount of light that is transmitted 
through the curtains and their transparency. While the color and weave of 
these curtains may be varied to suit the aesthetics of the interior dcor, 
the appearance of the windows is altered by the presence of the curtains. 

[Begin figure]
Figure 3-8 is an illustration of a Blast curtain system.
[End figure]

The curtains may either be anchored at the top and bottom of the 
window frame or anchored at the top only and outfitted with a weighted 
hem. The curtain needs to be extra long relative to the window with the 
surplus either wound around a dynamic tension retainer or stored in a 
reservoir housing. When an explosion occurs, the curtain feeds out of the 
receptacle to absorb the force of the flying glass fragments. 

3.4.5 GLAZING CATCH CABLE/BAR RETROFIT 

As explained earlier, laminated and filmed glazing is designed to hold the 
glass shards together if the window is damaged. Unless the window frames and 
attachments are upgraded to withstand the capacity of the laminated glass, 
there is a high possibility that entire sheets of glass would fly free of the 
window frames in a blast environment. Rigid catch bar systems have been 
designed and tested as a means of increasing the effectiveness of laminated 
window upgrades. The rigid catch bars intercept the laminated glass and 
disrupt their flight (see Figure 3-9). 

[Begin figure]
Figure 3-9 is an illustration showing a glazing catch bar. 
[End figure]

Rigid catch systems collect huge forces upon impact and require 
substantial anchorage into a very substantial structure to prevent failure. 
If either the attachments or the supporting structure are incapable of 
restraining the forces, the catch system will be dislodged and become part of 
the debris. Alternatively, the debris may be sliced by the rigid impact, 
severely limiting the effectiveness of the catch bars. 

Flexible catch bars can be designed to absorb a significant amount of the 
energy upon impact, thereby keeping the debris intact and impeding their 
flight into occupied spaces. They also may be designed to repel the debris 
from the failed glazing, as well as the walls in which the windows are 
mounted. The debris restraint system must be strong enough to withstand the 
momentum transferred upon impact, and the connections must be capable of 
transferring the forces to the supporting slabs and spandrel beams. Under no 
circumstances should the design of the restraint system add significant 
amounts of mass to the structure because it could be dislodged and present an 
even greater risk to the occupants of the building. 

3.4.6 ENERGY-ABSORBING CATCH CABLE SYSTEMS 

The use of cable systems has long been recognized as an effective means 
of stopping massive objects moving at high velocity. Cables are extensively 
used to absorb significant amounts of energy upon impact, and their 
flexibility makes them easily adaptable to many situations. The diameter of 
the cable, the spacing of the strands, and the means of attachment are all 
critical in designing an effective catch system. These catch cable concepts 
have been used by protective design window manufacturers as restraints for 
laminated lites. An analytical simulation or a physical test is required to 
confirm the adequacy of the cable catch system to restrain the debris 
resulting from an explosive event. 

High-performance energy-absorbing cable catcher systems retain glass 
and frame fragments and limit the force transmitted to the supporting 
structure. These commercially available retrofit products consist of a 
series of -inch diameter stainless steel cables connected with a shock-
absorbing device to an aluminum box section, which is attached to 
the jambs, the underside of the header, and topside of the sill. The 
energy-absorbing characteristics allow the catch systems to be attached 
to relatively weakly constructed walls without the need for additional 
costly structural reinforcement. To reduce the possibility of slicing 
the laminated glass, the cable may either be sheathed in a tube or an 
aluminum strip may be affixed to the glass directly behind the cable. 


3.4.7 UNREINFORCED MASONRY WALL DEBRIS CONTROL 

URM facade provides limited protection against air blast due to 
explosions. When subjected to overload from air blast, brittle 
unreinforced concrete masonry unit (CMU) walls will fail and the debris 
will be propelled into the interior of the structure, possibly causing 
severe injury or death to the occupants. Masonry debris may result from a 
100-pound TNT equivalent detonation within 300 feet or a 1,000-pound 
explosion within 1,000 feet and buildings may be subject to collateral 
damage due to an attack against a nearby building. Existing unreinforced 
CMU walls may be retrofitted with a sprayed-on polyurea coating to 
improve their air blast resistance. Polyurea materials are widely used as 
truck-bed liners and roof coatings; however, this innovative incremental 
rehabilitation technique takes advantage of their toughness and resiliency to 
effectively deform and dissipate the blast energy while containing the 
shattered wall fragments (see Figure 3-10). Although the sprayed walls may 
shatter in a blast event, the polyurea material remains intact and contains 
the debris. 

[Begin figure]
Figure 3-10 is an illustration showing spray-on polyurea. 
[End figure]

The blast mitigation retrofit for unreinforced CMU walls consists of an 
interior (and an optional exterior) layer of polyurea applied to exterior 
walls and lapped onto the adjacent floor and ceiling slabs. The polyurea 
provides a ductile and resilient membrane that catches and retains 
secondary fragments from the existing concrete block as it breaks apart 
in response to an air blast wave. The effectiveness of a spray-on polymer 
coating in controlling debris has been demonstrated through explosive 
testing at the Air Force Research Laboratory and by extensive numerical 
simulations. This retrofit is not applicable to load-bearing walls for which 
the preservation of structural integrity is required. 

Instead of the spray-on polyurea, an aramid (geotextile) debris catching 
system may be attached to the structure by means of plates bolted through 
the floor and ceiling slabs (see Figure 3-11). Similar to the polyurea 
retrofit, the aramid layer does not strengthen the wall, but instead 
restrains the debris from being hurled into the occupied spaces in the 
case of an explosion. 

[Begin figure]
Figure 3-11: Geotextile debris catch system. 
[End figure]

A steel stud wall construction may also be used to limit debris associated 
with masonry wall failure (see Figure 3-12). Commercially available 18 gauge 
steel studs may be attached web to web (back to back) and 16 gauge sheet 
metal may be installed outboard of the steel studs behind the cladding. While 
the wall absorbs a considerable amount of the 
blast energy through deformation, its connection to the surrounding 
structure must develop large tensile reaction forces. In order to prevent 
a premature failure, these connections should be able to develop the 
ultimate capacity of the stud in tension (FEMA, 2006a). The interior face 
of the stud should be finished with a steel-backed composite gypsum 
board product. 

[Begin figure]
Figure 3-12: Metal stud blast wall.
[End figure]

3.4.8 OTHER FACADE RETROFITS 

In addition to upgrading the facade to minimize debris associated with 
failed glass, other retrofits might include the bracing of parapets, gables, 
ornamentation, and appendages that might be propelled into occupied 
space. Although these upgrades are more likely to be associated with 
increased resistance to seismic motions or hurricane force wind loads, 
they may also be warranted for buildings exposed to blast loading. 
Similarly, masonry veneer, steel stud back-up, and the exterior wythe 
of cavity walls may be upgraded to improve their resistance to extreme 
loads; however, these upgrades are relatively invasive and are rarely 
implemented to minimize the debris associated with blast loading. Due 
to the difficulty of improving the capacity of these building components, 
debris catch systems are typically installed instead of strengthening the 
components themselves. Although canopies at building entrances are 
vulnerable to an exterior explosion, they are outside of the building 
envelope and are rarely upgraded to improve their resistance to blast 
loading. 

3.5 NONSTRUCTURAL MEMBERS 

Because of the likelihood of glass damage and the associated infill 
pressures, significant damage to nonstructural members in the 
exterior bays is likely. This damage will produce additional debris 
that may cause injuries and disrupt emergency mechanical systems, such 
as sprinkler systems, emergency lighting, and smoke exhaust systems. 
Consequently, critical nonstructural systems should be protected by means 
of improved support and lateral bracing. While it may not be feasible 
to upgrade mechanical systems without conducting a comprehensive 
interior renovation, there may be an opportunity to perform incremental 
rehabilitation as systems are renovated. Some nonstructural systems that 
may be considered for upgrade are: 

. Sprinkler piping 
. Emergency lighting 
. Mechanical and electrical equipment above ceilings 
. Masonry walls at interior stairs 
. Hazardous materials container 
. Transformers 
. Emergency generators 
. Boilers 
. Tanks 
. Chillers 

3.6 STRUCTURAL RETROFITS 

Unlike seismic upgrades of structural systems, which generally 
address the global lateral load resisting system, upgrade to 
resist blast loads are more local. Generally, measures that tie 
the structure together, that increase the redundancy and ductility of 
individual members and upgrades, and that transfer the lateral loads 
into the diaphragms improve the structures ability to resist blast loads. 
Since the capacity of members may be limited by the strength of the 
connections, upgrades must be comprehensive if they are to be effective. 

The incremental rehabilitation of the structure to accept the threat 
independent removal of any load-bearing member, as required by the 
alternate path method, is generally invasive and expensive. This typically 
requires the development of beam-to-column moment connections for steel frame 
construction and the installation of tension reinforcement through 
beam/column connections. Steel frame connections are often difficult to 
access and connection upgrades may be infeasible unless the structure is 
fully exposed. Similarly, the inclusion of tension reinforcement through 
concrete frame connections may be accomplished by grooving the existing 
concrete and bonding supplemental reinforcement with epoxy or the adhesion of 
a composite fiber reinforcement to the exterior of the members. 

In some cases, it may not be possible to retrofit an existing building to 
limit the extent of collapse to one floor on either side of a failed column. 
If the members are retrofitted to act as a catenarythe natural curve created 
by a flexible cord freely suspended between two fixed points the adjoining 
bays must be upgraded to resist the large lateral forces associated with this 
mode of response. The catenary behavior may be achieved through the 
application of a glass or carbon fiber material to the top and underside of 
the spandrel beams and slabs. Alternatively, 
steel plates may be through-bolted to the spandrel beams in order to 
develop continuity and axial capacity. However, developing the large 
lateral forces may require more extensive retrofit than is either feasible or 
desirable. In such a situation, it may be desirable to isolate the collapsed 
region rather than risk propagating the collapse to adjoining bays. This 
approach is best suited for arresting the horizontal progression of collapse 
in low structures with large floor plates. The creation of structural fuse 
planes prevents the lateral propagation of collapse. Vertical 
compartmentalization requires the structure resist the impact of debris from 
above without pancaking the floors below and this is more difficult to 
achieve. 

The incremental rehabilitation of existing structures to protect against a 
potential progressive collapse resulting from the detonation of a terrorist 
explosive may best be achieved through the localized hardening of vulnerable 
columns. These columns need only be upgraded to a level of resistance that 
balances the capacities of all adjacent structural elements. At greater blast 
intensities, the resulting damage would be extensive and termed global 
collapse rather than progressive collapse. 

Lightweight metal deck roof structures, without a concrete fill, are 
particularly susceptible to direct blast loading and suction associated with 
diffusion over the edge of the roof. Strengthening these roof systems 
may require extensive upgrades; however, the connections of the metal 
deck to the roof framing members and the roof framing members to 
the columns may also be upgraded to limit the extent of debris. While 
these systems may sustain significant damage in response to a sizeable 
vehicle-borne explosive threat, particularly for low buildings, improved 
connections protect occupants from falling debris hazards. Openings in 
walls and reentrant corners are not as critical for blasts as they are for 
multiple cycles of seismic base motions; however, they will create stress 
concentrations and must be developed with sufficient ductility to accept 
larger deformations. 

3.6.1 COLUMNS 

Conventionally designed columns may be vulnerable to the effects of 
explosives, particularly when placed in contact with their surface. Standoff 
elements such as partitions and enclosures may be designed to guarantee a 
minimum standoff distance; however, this alone may not be sufficient. A steel 
jacket or a carbon fiber wrap may be used to provide additional resistance to 
reinforced concrete structures (see Figure 3-13). These systems effectively 
confine the concrete core, increase the confined strength and shear capacity 
of the column, and hold the rubble together to permit it to continue carrying 
the axial loads. The capacity of steel flanged columns may be increased with 
a reinforced concrete encasement that adds mass to the steel section and 
protects the relatively thin flange sections. Alternatively, steel plate may 
be welded to flanged sections to create a box section that is more resistant 
to explosion. The details for these retrofits, and the corresponding 
connection upgrades, must be designed to resist the specific weight of the 
explosives and the standoff distance. 

[Begin figure]
Figure 3-13 s an illustration of a steel jacket retrofit detail. 
[End figure]

3.6.2 FLOOR SYSTEMS 

Floor systems that span between column lines resist gravity loads and 
contribute to the lateral resistance of the building, either through frame 
action or as diaphragms that transfer lateral forces to braced frames or 
shear walls. Steel construction typically relies on concrete-filled metal 
decking that spans between closely spaced filler beams, which in turn span 
girders along the column lines. Steel beams and girders typically possess 
equal resistance to both upward and downward loading and are capable of 
developing large inelastic deformations; however, their ability to resist 
extreme loading is often limited by the capacity of their connections. 

There is a greater variety of reinforced concrete floor systems, which may 
consist of beams and concrete slabs, beams and joists, waffle slabs, and flat 
slabs. Each of these systems optimizes the placement of reinforcement where 
they most efficiently resist the design loads; top reinforcement near the 
supports and bottom reinforcement at mid-span. Although the American Concrete 
Institute Building Code Requirements for Structural Concrete (ACI, 2005) 
requires additional continuous reinforcement for enhanced structural 
integrity, these nominal quantities do not resist the effects of direct blast 
loading and rebound. Furthermore, the effectiveness of the concrete sections 
to develop large inelastic deformations is governed by the confinement of the 
concrete within the steel cages. This confinement enhances both the ductility 
of the members and the ability to transfer shear forces across the cracked 
sections. Beam-to-column connections are often congested with vertical column 
reinforcement and horizontal beam reinforcements and are particularly 
vulnerable to blast loading. Confinement of the connection details, such as 
those used in the design of structures to resist seismic loading, is more 
likely to resist the 
effects of blast loading than conventional concrete detailing; however, the 
effectiveness of critical connection details must be confirmed through 
dynamic analysis. 

Flat slab structures do not rely on beams along edges to transfer loads 
to the columns; instead, they contain patterns of steel reinforcement 
within column strips and middle strips that develop the positive and 
negative moments that are imposed by the design loads. Because of the 
efficient use of materials, flat slab structures lack the redundancy of beam-
slab systems and are vulnerable to punching shear failures around the columns 
(see Figure 3-14). 

[Begin figure]
Figure 3-14 is an illustration showing flat slab failure mechanisms. 
[End figure]

Floor slabs are typically designed to resist downward gravity loading and 
have limited capacity to resist uplift pressures or the upward deformations 
experienced during a load reversal (i.e., blast). Therefore, floor slabs that 
may be subjected to significant uplift pressures, which may overcome the 
gravity loads and subject the slabs to reversals in curvature, require 
tension reinforcement at the top fiber of the mid-span locations and bottom 
tension reinforcement at the underside near the supports (see Figure 3-15). 
The failure of floor slabs in response to explosive loading propels debris 
onto to the slab below and increases the unbraced length of the supporting 
columns. Both the pancaking of slabs and the destabilization of columns 
increases the potential for progressive collapse. 

[Begin figure]
Figure 3-15 is an illustration showing effects of uplift and load reversal. 
[End figure]

The incremental rehabilitation of steel floor systems typically involves 
the welding of plates at the connections to increase their capacity. Often, 
the inaccessibility of the connections makes these upgrades difficult to 
achieve. The incremental rehabilitation of conventional concrete construction 
in order to increase confinement, improve ductility, and provide for load 
reversals relies on techniques that were developed for the seismic upgrade of 
structures. If the slab does not contain this tension reinforcement, it must 
be supplemented with a lightweight carbon fiber application that may be 
bonded to the surface at critical locations. Carbon fiber reinforcing mats 
bonded to the top surface of slabs would strengthen the floors for upward 
loading and reduce the likelihood of slab collapse from blast infill uplift 
pressures, as well as from internal explosions in mailrooms or other 
susceptible spaces. This lightweight high tensile strength material would 
supplement the limited capacity of the concrete to resist these unnatural 
loading conditions. Preliminary experience shows these retrofits to be 
effective. An alternative approach is to notch grooves into the top of the 
concrete slabs and then epoxy carbon fiber rods into those grooves. Although 
this approach may offer greater capacity, it is much more invasive and has 
not been evaluated with explosive testing. 

3.6.3 LOAD-BEARING UNREINFORCED MASONRY WALLS 

URM load-bearing-wall buildings are prohibited by the Department of 
Defense Unified Facilities Criteria where blast resistance is required. 
These buildings may sustain severe damage when subjected to 100 
pounds of TNT-equivalent explosives at a standoff distance of 30 feet 
or 1,000 pounds of TNT-equivalent at a standoff distance of 150 feet. 
This makes the URM, load-bearing-wall buildings vulnerable to damage 
even when the structure is not the primary target of the attack. For this 
type of structure, it is not enough to just control the debris resulting 
from an explosive event; the structural integrity of the walls must be 
preserved to prevent structural collapse. Strengthening of the walls may 
be accomplished by means of a shotcrete sprayed onto the wall with a 
welded wire fabric. This method supplements the tensile capacity of the 
existing wall and limits the extent of debris that might be propelled into 
the protected space. Steel sections may also be installed against existing 
walls to reduce the span and provide an alternate load transfer to the floor 
diaphragms. Alternatively, stiffened steel-plate wall systems may be designed 
to withstand the effects of explosive loading by providing both redundancy 
and fragment protection. These load-bearing-wall retrofits require a more 
stringent design, capable of resisting lateral loads and the transfer of 
axial forces. Stiffened wall panels, consisting of a steel plate to catch the 
debris and welded tube sections spaced approximately 3 feet on center, 
supplement the gravity load-carrying capacity of the bearing walls and 
prevent the debris from entering the protected space. Finally, internal 
strengthening of URM walls may be achieved using a system wherein cables are 
snaked through holes that are cored through the wall and anchored in place 
with an injected grout without disturbing the finishes. 

3.6.4 TRANSFER GIRDERS 

Key elements that may be exposed to the explosive threat, such as transfer 
girders and mega-columns, warrant the most immediate attention to incremental 
rehabilitation. The risk assessment will identify the most 
critical members and the priority for hardening. If structural upgrades 
such as concrete encasement or steel jacketing are not feasible, then 
vulnerability of key elements may be reduced by means of architectural 
enclosures that provide increased standoff distance. Small increases 
in standoff distance greatly reduce the intensity of the near-contact 
blast loading and increase the survivability of structural members. If 
the architecture permits, this approach is both inexpensive and highly 
effective; however, advanced analysis may be required to demonstrate the 
performance of the structural members in response to the reduced load 
intensity. These key components should also be upgraded to increase 
the resistance of fireproofing in response to blasts to account for a wider 
range of potential threats and hazards. If the connections of vulnerable 
steel-braced and moment-frame members are accessible, they may be upgraded to 
develop the plastic capacity. 

3.7 BLAST PROTECTION MEASURES 

The preceding discussions of blast threat mitigation measures 
(Sections 3.33.6) can be condensed into the following list. 
It is presented here as an example of measures that might be 
generated by the FEMA 452 process and implemented using FEMA 459, 
as discussed in Chapter 2. These measures are all included in the list that 
comprises the vertical axes of the matrices in Section 2.3.

Site upgrades 

. Increased standoff distance 
. Anti-ram barriers 
. Speed calming devices 
. Operable barriers 

Building envelope upgrades 

. Glazing 
 . Fragment retention film 
 . Laminated glass 
 . Blast curtains 
 . Glazing catch cable/bar 
 . Energy-absorbing cable systems 
. URM 
 . Sprayed-on polymer 
 . Geotextile fabric 
 . Steel stud and sheetmetal construction 
. Other building envelope retrofits 
 . Bracing parapets, gables, ornamentation, and appendages 
 . Anchoring cladding 
 . Anchoring masonry veneer 
 . Anchoring steel stud backup 
 . Anchoring exterior wythe in cavity walls 
 . Installing debris catch systems for facade elements 
 . Increasing the roofs resistance to blast 
 . Upgrading connections of light metal deck roofs to the structure 

Structural upgrades 

. Upgrading the structure to make it more ductile 
. Upgrading spandrel beams to achieve catenary response 
. Upgrading slabs to achieve catenary response 
. Increasing standoff distance around vulnerable columns 
. Localized hardening of vulnerable columns 
. Enhancing floor slab upload resistance 
. Installing load-bearing URM retrofits 
 . Shotcrete 
 . Steel sections 
 . Stiffened steel-plate wall system 
 . Reinforcing 
. Retrofitting transfer girders 

Nonstructural upgrades 

. Sprinkler piping 
. Emergency lighting 
. Mechanical and electrical equipment above ceilings 
. Masonry walls at interior stairs 
. Restraint of hazardous materials containers 
. Transformers 
. Emergency generators 
. Boilers 
. Tanks 
. Chillers 

3.8 BLAST PROTECTION MEASURE COST CONSIDERATIONS 

The major costs to consider in protection are those associated with 
standoff distance and building component costs. Cost reduction achieved by 
decreasing standoff and perimeter length must be evaluated against the 
comparative increased cost of other solutions, such as hardening the 
building, providing more guards, increasing camera surveillance, relocating 
the facility, or relocating key building occupants to interior locations. 
These costs must be evaluated with respect to achieving an acceptable level 
of risk. 


Principles OF Design FOR Risk Reduction Related to 
Chemical, Biological, and Radiological threats 4 

Recent terrorist events have increased interest in the vulnerability 
of buildings to CBR threats. Of particular concern are building 
HVAC systems, because they can become an entry point and 
distribution system for airborne hazardous contaminants. Even without 
special protective systems, buildings can provide protection in varying 
degrees against airborne hazards that originate outdoors. Conversely, the 
hazards produced by a release inside a building can be much more severe 
than a similar release outdoors. Because buildings allow only a limited 
exchange of air between indoors and outdoors, not only can higher 
concentrations occur when there is a release inside, but hazards may 
persist longer indoors. 

The results of the FEMA 452 risk assessment, including the vulnerability 
checklist, will likely yield many opportunities to reduce risk over time by 
upgrading the buildings HVAC and other systems. This chapter describes the 
nature of the CBR threat and some of the opportunities for risk reduction. 

4.1 Overview OF CBR threats 

there are hundreds of toxic chemical, biological, and radiological 
agents that could be released in an accident or terrorist attack. 
Among them are chemical-warfare agents, industrial chemicals, 
radioactive materials, toxins, irritants, incapacitants, and biological 
agents, which are mainly bacteria, viruses, and rickettsiae. The potential 
hazard each agent presents is determined by its toxicity, persistence, and 
quantity. 

Toxicity among these agents varies over several orders of magnitude. 
Toxicity and likely quantity of exposure determine the level of protection 
needed for protective systems. Toxic agents also vary widely in persistence. 

Gases such as chlorine are non-persistent and usually dissipate in 
minutes outdoors. Radiological agents and some of the biological 
agents are extremely persistent and may remain toxic in an indoor or 
outdoor environment for decades unless decontamination measures are 
undertaken. 

Toxicity and persistence determine the extent and duration of a hazard, 
but the more important characteristics relative to protective strategies are 
how readily the agents can be filtered and detected. Filtration involves the 
removal of a toxic agent from an air stream. The full spectrum of toxic 
agents 
includes gases, vapors, and aerosols (finely divided particles). With current 
technology, filtering the full spectrum of toxic agents requires three 
different processesmechanical filtration for aerosols, physical adsorption 
for chemical agents of low vapor pressure, and chemisorption for chemical 
agents of high vapor pressure. The latter two are usually incorporated into a 
single filter called an adsorber. 

With regard to detection, most of the toxic chemicals have warning 
properties; that is, they can be detected by the human sensesby smell, 
irritation of the eyes/respiratory tract, color, and in some cases by taste 
before severe effects occur. There are no warning properties associated with 
airborne microbial pathogens or radioactive aerosols. 

Most toxic chemicals produce immediate effects. Automatic detectors are 
available for the accurate detection of a few of the most toxic chemicals. 
Single-pass filtration systems of the high level of efficiency necessary for 
protection against toxic chemicals are generally expensive and cannot filter 
all toxic chemicals. 

Biological agents are neither perceptible by the senses nor detectable in 
real time by automatic detectors. Their effects are delayed. The particle 
size range of concern for biological aerosols is 1 to 5 microns, and the 
very high filter efficiencies necessary for these aerosols can be achieved 
with HEPA filtration. 

Similarly, radiological agents are not perceptible by human senses and 
their effects are delayed. However, they can be detected in real time and 
are easier to decontaminate from indoor spaces than biological agents. 
They can be filtered at very high efficiencies with HEPA filters. 

4.2 Principles OF Design FOR Risk 
Reduction Related to CBR 

For a building owner or manager, reducing CBR risk means 
reducing the CBR vulnerability of the building. There are several 
options for doing so that vary in effectiveness and cost. The most 
effective measures are those that are preventive and protective. 

Preventive measures are those intended to prevent the release of a toxic 
agent in or into a building. Protective measures are those that impose 
barriers and high-efficiency filter systems between people and spaces that 
are 
or may become contaminated. A building may be considered as a 
system of barriers. Protective measures can be achieved by improving the 
buildings filtration system, making the barrier system more complete, 
and applying pressures with fans to overcome the natural pressures of 
wind and buoyancy acting on air leakage paths. 

There are two types of protective measures: passive (continuously 
protective) and active (initiated upon determining that a hazard exists or is 
imminent). 

The nature of the CBR threat to a specific facility determines the strategy 
for applying preventive and protective measures. A building for which the 
threat, vulnerability, and asset value/consequence are considered high 
requires a high level of protection. If the combination of threat, 
vulnerability, and asset value/consequence is low, a low level of protection 
is appropriate. If the primary threat is an indoor or air-intake release, the 
greatest benefit is derived from physical security enhancements. Enhanced 
filtration of recirculated air is also beneficial. If the primary threat is 
an 
outdoor release, enhanced filtration of the ventilation air and/or enhanced 
safe rooms are most beneficial for reducing risk. 

4.3 Prioritization OF CBR 
Vulnerabilities: incremental 
improvements 

there are several improvements that can protect building occupants 
from a CBR release or prevent a release from occurring inside or 
directly into a building. However, not all measures are effective 
against all types of agents and against all delivery methods. Systems 
involving air-filtration and pressurization are the most effective, and they 
provide secondary, but significant, benefits of better indoor air quality. 
They are also most expensive in terms of initial cost, operating cost, and 
maintenance cost. 

There are seven distinct levels of CBR protection for buildings. These 
levels are listed below in general order of cost. Each succeeding level 
involves increased cost and provides greater protection for occupants 
and the building. Each level provides additional protection to the one 
preceding it, if the threat, vulnerability, and criticality so indicate. 
Seven 
options for CBR Protection include: 

1. Operational measures and expedient protection 
2. Enhanced physical security 
3. Enhanced sheltering in place 
4. Aerosol filtration, medium level 
5. Gas-phase filtration, medium level 
6. Aerosol filtration, high level 
7. Gas-phase filtration, high level 

4.3.1 Level 1, Operational Measures and 
expedient Protection 

Level 1 consists of basic, low-cost preparations for reducing the effects of 
a 
CBR attack. These are primarily operational measures and require no 
modifications to the building or special equipment. These operational 
measures involve developing procedures (active measures) for responding 
to a release of toxic agent, including: 

. Expedient sheltering in place 
. Designating safe rooms: interior rooms with a low air exchange rate 
. Identifying switches for air handling units and fans for deactivation 
. Defining procedures and responsibilities for sheltering and for 
purging the building after plume passage 
. Establishing a building-wide notification system 
. Familiarizing building occupants with procedures and 
responsibilities 
. Evacuation 
. Purging 
. Using escape respirators 

4.3.2 Level 2, enhanced Physical security 

Level 2 measures focus on preventing the internal or air-intake release 
of agents. Incorporating building modifications or installing security 
equipment may include: 

.  Securing air intakes, mechanical rooms, and HVAC plenums against 
unauthorized access 
. Performing entry inspections 
. Installing and monitoring video surveillance equipment 
. Instituting mail screening procedures 
. Maintaining operational security to building plans and signage 
. Applying mechanical and architectural isolation of lobby, mailroom, 
cloakroom, and loading docks 

4.3.3 Level 3, enhanced sheltering in Place 

Level 3 includes modifications to the building to make emergency 
protective actions more effective and to isolate zones in which indoor 
releases are most likely to occur. Modifications include: 

. Installing single-switch control of fans for sheltering and purging 
. Sealing the envelope of the building and selected safe room(s) 
. Installing automatic dampers for outside air intakes and exhaust fans 
. Implementing a public address system to achieve rapid implementation of 
emergency actions 
. Isolating mechanical spaces that require large volumes of outside air 
by mechanical and architectural means 
. Installing separate fans and air streams for ventilation and 
recirculation, as well as cooling and heating of safe rooms 
. Installing recirculation filter units in safe rooms 

4.3.4 Level 4, aerosol Filtration, Medium Level 

Level 4 is the first of four levels involving improved air filtration. It is 
the least costly of the four levels of filtration and includes only aerosol 
filtration and the use of existing air-handling units that filter mixed air 
(both ventilation air and return air) with the same filters. Aerosol 
filtration provides protection against biological agents, radiological 
agents, 
and most irritants. Level 4 may be applied to selected zones only or to the 
entire building (with the exception of mechanical spaces requiring large 
volumes of outdoor air). It provides benefits against both outdoor and indoor 
releases and requires: 

. Sealing filter frames to minimize bypass 
. Installing filters of greater depth/surface area and higher Minimum 
Efficiency Rating Value (MERV) rating, such as MERV 14, 15, or 16 
mini-pleats 
. Operating at outdoor air fractions that produce positive internal 
pressures of approximately 0.1 to 0.2 inch, water gauge 

4.3.5 Level 5, gas-Phase Filtration, Medium Level 

Level 5 expands filtration capability in air handling units to include gas 
absorbers, which are the filters needed to remove chemical vapors and 
gases. Using indoor-air-quality type adsorption systems that have relatively 
low pressure drops produces initial removal efficiencies of about 99 percent 
for physically adsorbed (low vapor pressure) agents and provides about 1 year 
service life. Filtration of chemicals of high vapor pressure is poor. This 
type of filtration may be applied to the entire building (except for 
mechanical spaces requiring large volumes of outdoor air) or to selected 
zones. It provides protective benefits against both outdoor and indoor 
releases and requires: 

. Indoor-air-quality type, low resistance adsorbers that may necessitate 
substantial modification to air handling units 
. Operating at outdoor air fractions that produce positive internal 
pressures of approximately 0.1 to 0.2 inch, water gauge 
. Vestibules or revolving doors for highly protected zones 

4.3.6 Level 6, aerosol Filtration, High Level 

Level 6 increases the level of protection against an outdoor release of 
toxic aerosols substantially over Level 4, but it does not provide any 
benefits over Level 4 against an indoor release. Level 6 requires the 
installation of makeup-air/ventilation units with HEPA filters. This may be 
applied to the entire building or selected zones. It involves: 

. Installing ventilation/makeup-air units with HEPA filtration for each 
zone to be protected 
. Vestibules or revolving doors for highly protected zones 
. Operating at outdoor air fractions that produce positive internal 
pressures of approximately 0.1 to 0.2 inch, water gauge 

4.3.7 Level 7, gas-Phase Filtration, High Level 

Level 7 involves the installation of high-efficiency gas adsorbers in 
ventilation/makeup air units serving protected zones. It expands the 
protective capability to toxic gases and vapors in addition to the aerosol 
capability of Level 6. Its cost is relatively high, and costs vary with the 
tightness of the envelope being pressurized. It provides the highest, most 
complete level of protection against an outdoor release and may be applied to 
the entire building or selected zones. It involves: 

. Installing ventilation/makeup air units with high efficiency gas 
adsorbers as well as HEPA filters for each zone protected 
. Vestibules and revolving doors for the protected zones 
. Operating at outdoor air fractions that produce positive internal 
pressures of approximately 0.1 to 0.2 inch, water gauge. 

4.4 Design guidance FOR CBR Protective Levels 

the following sections contain detailed descriptions and discussions 
of the seven levels summarized above. 

4.4.1 Level 1, Operational Measures and 
expedient Protection 

4.4.1.1 scope and Capabilities 
This basic level of protection is achieved by preparing emergency plans 
and procedures, then familiarizing building occupants with these plans 

and procedures for responding to a summary of capabilities for level 1 toxic-
agent release. These plans and procedures cover: 

- Expedient sheltering in place
- Purging
- Evacuating
- Using escape respirators

Each of these is an active measure; that is, it is initiated only when a
hazard is present or known to be imminent. Active measures are most
practical against chemical agents because chemical agents can be
immediately detected, either by their warning properties (particularly odor), 
automatic detectors, or visible/audible signs of a release. Biological agents 
are not detectable in real time; therefore, these measures are not expected 
to 
apply for biological agents unless there is forewarning of some kind provided 
by those who are releasing, transporting, or storing the agent.

Sheltering in place is employed mainly for outdoor releases, evacuation
mainly for indoor releases, and escape respirators for either indoor or
outdoor releases.
 
[text box]
Summary of Capabilities for Level 1 Sheltering in place provides a low level 
of protection from chemical agents released outdoors. Evacuation and purging 
(when the nature of the release is known) provide low-level protection in 
response to indoor releases. Operational measures and expedient protection 
are 
not generally practical for biological agents
because biological agents cannot be detected in real time. Operational 
measures and expedient protection also apply to radiological agents, but 
automatic detectors (e.g., radiac meters) are likely to be necessary.
[end text box]



4.4.1.2 Methods and Requirements Sheltering in Place 

Some content addressing protective actions in this section was originally 
published in Protecting Buildings and their Occupants from Airborne Hazards, 
U.S. Army Corps of Engineers, October 2001. For maximum protection, 
sheltering 
in place requires two actions to temporarily change a buildings indoor-
outdoor air exchange rate. The first is to reduce the air-exchange rate 
before 
contaminated air begins to enter the building. This involves shutting off all 
fans that promote the 
exchange of air between indoors and outdoors, closing all exterior doors 
and windows, and shutting off elevators. 

The second action is to increase the air-exchange rate after the outdoor 
hazard has dissipated. This is necessary because even a tightly sealed 
building will not fully prevent contaminated air from entering. However, 
outdoor air will enter more slowly, and once the external hazard has 
passed, the building will release the contaminated air slowly 

The advantage of sheltering in place is that it can be implemented rapidly. 
The disadvantage is that its protection is variable and diminishes with the 
duration of the hazard. The amount of protection varies with the building air 
exchange rate, the duration of exposure, and the period of occupancy after 
the 
hazardous condition has passed. 

Sheltering can be employed as a precautionary measure if there is an 
impending release (e.g., a tanker truck crash involving a fire that releases 
toxic material, a non-windward release when winds shift, or a release at a 
great distance from the building). Sheltering is not appropriate for 
protecting people when the duration of exposure to an outdoor hazard is long 
and continuous, i.e., for several hours. 

The need to shelter in place may be indicated by (1) visible or audible 
signs of release of agent, (2) information from authorities that there has 
been a release in the area, (3) observed symptoms of chemical-agent 
exposure in people outside the building, or (4) automatic detectors, if 
available, sampling air outside the building or outside air as it is drawn 
into the building. 

One option for sheltering is to use designated rooms or safe rooms, if 
they are better sealed than the building as a whole and/or the location 
of the room is less subject to wind pressures or buoyancy pressures that 
induce infiltration. Safe rooms may also be located in the building on 
the side opposite a likely source (e.g., a nearby chemical storage facility 
or 
railroad line). The safe rooms must be of a number and capacity to 
accommodate 
all building occupants and visitors. Generally, safe rooms require a minimum 
of 5 square feet per person, with 10 square feet per person preferred. 

Using a sealed interior room within a sealed building provides greater 
protection than a sealed building by itself. A sealed interior room has 
greater resistance to infiltration flow driven by wind and buoyancy. 
However, use of designated safe rooms is not essential. In many cases, 
office buildings do not have sufficient space in interior rooms for 
sheltering all building occupants. 

Figure 4-1: Signage designating safe room. 

To be effective in large commercial buildings, sheltering in place requires 
planning and preparation. All exterior doors must be secured and all air 
handling units and exhaust fans must be turned off. Procedures for a 
sheltering plan, therefore, should include: 

. Identifying all air handling units, fans, and the switches needed to 
deactivate them 
. Identifying procedures for purging if an indoor release occurs, such as 
opening doors and windows; turning on smoke fans, air handlers, and 
exhaust fans that were turned off to shelter; and setting air-handlers 
on maximum outdoor air 
. Designating safe rooms (see Figure 4-1), interior rooms having a lower 
air exchange rate that may provide a higher level of passive protection 
. Establishing a building-wide notification system 
. Familiarizing occupants with the procedures and responsibilities for 
sheltering in place 

Although sheltering is for protection against an external release, 
sheltering in place on one or more floors of a multi-story building after 
an internal release has occurred on a single floor is also possible, though 
more complex. Under such conditions, stairwells must be isolated by closed 
fire doors, elevators must not be used, and clear evacuation 
routes must remain open in case evacuation becomes necessary. Escape 
respirators may be needed if the only evacuation routes are through 
contaminated areas. 

Purging 

Emergency actions for purging a building and reducing occupants 
exposure include turning on a buildings ventilation fans and smoke-
purge fans and increasing air-handling units outdoor air fraction 
to nominal 100 percent. Purging is useful primarily when the agent 
is known, the source of the agent is indoors, and as the final step in 
sheltering in place. The ventilation system and smoke purge fans can 
also be used to purge the building after an outdoor hazard has dissipated 
and it has been confirmed that the agent is no longer present near the 
building. 

The location of the source and the time of the release should be 
carefully considered when purging. The source of agent must be inside 
the building; if not, purging should not be attempted. If the hazardous 
material has been identified before release or immediately upon release, 
purging should not be employed, as it may spread the hazardous material 
throughout the building or zone. In this case, all air-handling units 
should be turned off to isolate the hazard while evacuating or temporarily 
sheltering in place. 

Evacuating 

Evacuating is the most common protective action when there is an 
airborne hazard in a building. In most cases, existing plans for fire 
evacuation apply. Though evacuating is the simplest and most reliable 
action, it may not be the best action for an outdoor release, particularly 
one 
that is widespread. Determining whether the source of the agent is indoors or 
outdoors is an important consideration in a non-fire evacuation. 

If the source is outdoors, and the agent has infiltrated the building, 
evacuation is not the safest action (unless the source has dissipated), 
and the use of respirators is appropriate. Sheltering in place may also be 
employed, but generally should not be used once the hazardous material 
has entered the building. Evacuation routes may also be hazardous if they 
take people through contaminated areas as they leave the building. 

Alternate routes that do not pass through the main lobby are best. For 
multi-story buildings, the elevators should be avoided because elevator 
movement promotes the exchange of air between and among floors. 
Assembly points should be designated outside the building so people can 
be accounted for or be given additional instructions. 

Using Escape Respirators 

Several models of universal-fit escape respirators have been developed for 
short-duration escape-only protection against chemical-warfare agents, 
aerosols (including biological agents), and some of the toxic industrial 
chemicals (see Figure 4-2). The National Institute for Occupational Safety 
and 
Health has a certification process for such respirators. Most of these 
respirators have their protective seals at the neck, rather than around the 
face, and consequently do not require special fitting techniques or multiple 
sizes to fit a large portion of the adult population. Training is required to 
use the masks properly. Depending on mask design, the wearer breathes through 
a mouth bit or uses straps to tighten a nose cup around the nose and mouth. 

The protective capability and shelf life of these masks vary with the design. 
The filter units of the masks contain both HEPA filters and packed carbon 
adsorbers, so they will remove chemical and biological aerosols, as well as 
chemical vapors and gases. Although the carbon filters are designed to filter 
a broad range of toxic chemicals, they cannot filter all chemicals. 

For example, the filters of escape masks are not effective against some 
chemicals of high vapor pressure. Unless they have a special filter, they 
provide no protection against the carbon monoxide that is produced in 
fires. Other escape hoods are available that employ compressed oxygen 
cylinders, rather than air filters, to provide eye and respiratory protection 
for short periods that vary with the intensity of the activity (i.e., 
walking, 
sitting, and climbing/descending stairs). 

Plans for training, fitting, storing, and record retention procedures 
should be established for escape masks and respirators. 

Figure 4-2: Escape respirators. 


4.4.1.3 Cost Considerations 

Costs of Expedient Sheltering In Place 

The initial costs of establishing a basic sheltering-in-place capability are 
small where space is available. These costs are associated with: 

. Conducting a survey to identify safe rooms 
. Defining, printing, and distributing the sheltering procedures and 
familiarizing the building occupants with these procedures 
. Assigning responsibilities for: closing doors, turning building fans 
off/on, 
and acting as safe room monitors in an emergency 
. Creating signage designating the safe room and providing instructions 
for the occupants 
. Keeping a supply of bottled drinking water in each safe room 
Operating and maintenance costs are those associated with periodic 
training and exercises, such as an annual sheltering drill, and 
replenishing supplies in the safe rooms. 

Costs of Escape Respirators 

The initial costs of employing escape respirators that meet requirements 
developed by the U.S. Army and/or the National Institute of 
Occupational Safety and Health include: 

. Purchasing respirators (approximate unit cost ranges from $100 to 
$300). This may include the purchase of respirators for visitors and 
new employees. 

. Initial training in use of the respirators. 

. Establishing an inventory system for the respirators that addresses 
serviceability checks and shelf life. 
The operating and maintenance costs of escape respirators include: 

. Replacement costs for respirators or respirator filters. Air-purifying 
type respirators require replacement every 4 to 5 years. Self-contained 
breathing apparatuses have a shelf life of 10 years. 

. Maintaining an inventory system, conducting refresher training, 
reissuing serviceable unused respirators, and ordering and issuing 
replacement respirators or filters. Cost data from one Federal facility 
show this cost to be roughly 10 percent of the respirator costs per year. 

4.4.2 Level 2, Physical security 

4.4.2.1 scope and Capabilities 

The purpose of the physical security
measures applied in this level is to prevent
the release of an agent from a point inside
the building or through a penetration in
the building shell from a point near the
building.

These physical security measures, which
also provide benefit against other criminal
acts, include five measures as described in
4.4.2.2 below.

Physical security measures are preventive
measures; they serve to deter potential attackers and to prevent the
release of agent in or into the building. They are effective only within the
building and/or its secure perimeter; they apply to indoor releases and
outdoor releases near the building.

[text box]
Summary of Capabilities for Level 2
Level 2 consists of physical security measures,
preventive or deterrent measures that apply to
indoor releases or outdoor releases close to the
building.
These measures apply to all toxic agents
chemical, biological, and radiological
agentsalthough detectability makes them
most practical for chemical agents.

[end text box]

Among the security measures presented below, only the entry inspection 
requires the capability to detect toxic agents. Because of technical 
challenges in detecting and reliably identifying agents, entry inspection 
is most practical for chemical agents and least practical for biological 
agents. 

4.4.2.2 Methods and Requirements Securing Air Intakes 

Securing air intakes is the highest priority physical security measure 
(see Figure 4-3). There are, however, several degrees of vulnerability 
for air intakes. Generally, the more difficult an intake is to access for 
surreptitious insertion of a toxic agent, the lower its vulnerability. 
Elevating intakes is the best approach to decreasing vulnerability. In 
retrofit, however, doing so can be expensive and require architectural 
changes that may not be aesthetically acceptable. There are less 
expensive, less effective measures that can be taken to reduce intake 
vulnerability, such as installation of security fencing and surveillance 
cameras. Whether an intake should be secured depends on its 
vulnerability and the level of threat to the building. 

Figure 4-3: Typical air intakes. 

Securing Mechanical Rooms and HVAC Plenums 

Securing mechanical rooms is a relatively inexpensive means of denying 
access to the HVAC system (except for the outside air intakes). Unsecured 
mechanical rooms present a vulnerability similar to but lower than 
unsecured outside air intakes. In most cases, mechanical rooms are 
accessed from inside the building; therefore, the routes of access are 
subject to the physical security of the building. 

HVAC ceiling plenums present an accessible pathway to the air-handling 
units, in which a dissemination device could be concealed by lifting a 
drop-ceiling tile. Plenum return pathways are not present in buildings 
with ducted returns and cannot be secured in buildings with hallway 
returns. Securing the ceiling plenum is impractical in most applications 
because access to the ceiling plenum must be retained for maintenance 
purposes. 

Performing Entry Inspections 

Adding entry inspections to prevent containers of toxic agents from being 
brought into a building is practical only if security guards control access 
to 
the building. Entry inspections have varying degrees of effectiveness. They 
can be effective for both deterrence and detection. Detecting toxic agents in 
containers is difficult, however, as there is no practical technology for 
rapid, non-intrusive detection/identification of toxic agents. Current 
methods 
of detection are based on the type of container (e.g., pepper spray devices) 
or on quantities of specific chemicals detected on exposed surfaces. 

Performing entry inspections in a lobby that is isolated architecturally and 
mechanically from the rest of the building is best. Such isolation should 
involve measures described in 4.4.3.2. In some cases, performing entry 
screening in a separate building (i.e., a visitors center) is more efficient 
and effective than modifying a lobby for isolation. Similarly, it may cost 
less to receive, inspect, and sort mail and packages in a separate building. 

Employing Video Surveillance 

The principles of deterrence and detection are also applied in the use of 
video surveillance equipment. For detection to be effective in preventing 
or mitigating the effects of a release, images from the cameras must be 
monitored continuously in real time. For deterrence, the surveillance 
must be overt rather than covert. Because of privacy concerns, overt 
surveillance is most commonly employed in office buildings. 

Generally, surveillance cameras should be placed in common areas that 
are not within the normal view of security personnel. Indoors, these 
areas may include hallways, cloakrooms, and obscure parts of the lobby. 
Outdoors, suitable placement may include unsecured air intakes and 
areas where vehicles or pedestrians may release an agent that would be 
transported into the building. 

Other Security Considerations 

Building plans may contain information relevant to CBR vulnerabilities. 
For this reason, access to drawings and specifications should be restricted. 

4.4.2.3 Cost Considerations 

The cost of installing security equipment varies substantially with the 
number of surveillance cameras, resolution and features of cameras, and 
monitors and recording equipment. 

4.4.3 Level 3, enhanced safe ROOMs and isolated Zones 

4.4.3.1 scope and Capabilities 

Level 3 CBR protection involves 

Level 3 CBR protection involves
increased protection against
indoor releases. This level includes
architectural and mechanical
modifications to designated safe
room(s) to increase the protection
the safe room can provide, and
to zones of concern, such as the
mailroom and lobby, to isolate
them from the rest of the building.
The mailroom is a primary zone of
concern, and the lobby is a zone
of concern for access-controlled
buildings. Isolating zones of concern
is a passive measure that prevents the
transport of airborne agents to other spaces of the building.

[text box]
Summary of Capabilities for Level 3
Level 3 mitigates indoor releases. It applies to
all types of agents: chemical, biological, and
radiological.
These measures prevent an agent released in a lobby
or mailroom from migrating to other parts of the
building and require access control and some level
of entry screening.
For enhanced sheltering in place, the protective
capabilities described in level 1 apply.

[end text box]


4.4.3.2 Methods 
Safe Room Enhancements 

There are three classes of safe room, as defined by U.S. Army documents 
on CBR collective protection (USACE, 2001). These classes provide three 
levels of protection, with Class I being the most protective. 

Class I safe rooms are ventilated and pressurized by air filtered at high 
efficiency. 

Class II safe rooms have air filtration with either no ventilation or a 
ventilation rate that produces little or no overpressure. 

Class III safe rooms are unventilated and have no air-filtration equipment. 

These safe rooms apply what is commonly referred to as sheltering in 
place. 

The features listed below facilitate rapid transition to sheltering mode 
and improve the level of protection a CBR safe room provides. These 
apply mainly to Class II and III safe rooms, but some apply to Class I. The 
design of Class I (pressurized) safe rooms is covered under Level 7. 

For commercial buildings, these enhancements are as follows: 

. Single-switch, rapid-shutdown capability for all fans that induce 
indoor-outdoor air exchange (See Figure 4-4). This includes shutdown 
capability for ventilation fans, exhaust fans, and air-handling units that 
draw outside air. 

Figure 4-4: A single switch for stopping HVAC fans. 


. Sealing measures. The level of protection varies with the tightness of 
the building in its sheltering configuration; the lower the air exchange 
rate, the higher the level of protection. 

. A public-address system to rapidly instruct all people in the building to 
shelter in place (i.e., not to exit the building or open exterior doors). A 
broadcast voice system is preferable to a tone-alert, ring-down, or computer-
screen message system because it is the most rapid and 
reliable. 

. Dampers for outside air intakes and exhaust fans. Dampers should 
be automatic and interlocked with the fan operation and must be 
maintained in good working order. 

Typical dampers are not effective enough to allow heating and air 
conditioning in the safe room while in the sheltering mode. Safe use of 
an air-handling unit serving a CBR safe room requires a recirculation fan 
separate from the makeup air fan. Cooling or heating in the safe room in 
the sheltering mode can be safely accomplished with separate ventilation 
and recirculation fans, when the damper for the ventilation fan is closed. 

A system with separate fans eliminates the potential for internally induced 
infiltration that typically occurs with an air-handling unit (single fan and 
damper) in the full recirculation mode. 

Filtering recirculated air in a safe room increases the protection level of 
the safe room from Class III to Class II. Some recirculation filter units 
have 
substantial adsorbers as well as high-efficiency particulate air filters and 
are suitable for enhanced sheltering in place (See Figure 4-5). To improve 
the 
safe rooms protection against chemical agents, the filter unit must have a 
substantial gas adsorber. The adsorber removes most chemical agents, while 
the 
high-efficiency particulate filter, found in most recirculation filter units, 
removes biological agents and other aerosols such as radioactive dust, tear 
gas, and pepper spray. While recirculation filters have the capability of 
removing biological agents, it is unlikely that the safe room would be used 
in 
the case of a biological release due to limitations in detection capability 
for biological agents. 

Figure 4-5: Two recirculation filter units. 

Isolating the Lobby and Mail Room 

The lobby and mailroom are two spaces in an office building in which a 
toxic agent release would be most likely to occur. Isolating these spaces 
architecturally and mechanically reduces the probability that large 
portions of the building will become contaminated by an indoor release. 
The probability of a lobby release is higher if the building is access-
controlled and the lobby is open to the public. 

Isolating these spaces from the rest of the building may require both 
architectural and mechanical changes, including: 

. Full-height walls 
. A dedicated air handling unit (serving only the space) if an all-air 
HVAC system is used 
. An exhaust fan or system balancing to maintaining the space at a 
negative pressure relative to the rest of the building 
. Doors into and out of the lobby that are normally closed (The 
frequency of entries and exits determines whether vestibules or 
revolving doors are also required.) 
4.4.3.3 Cost Considerations 
Initial costs vary widely, as lobbies generally require architectural changes 
to place a barrier and doorway between the lobby and adjoining spaces. 
Mechanical changes would require a separate air-handling unit for the 
space. 

4.4.4 Level 4, aerosol Filtration, Medium Level 

4.4.4.1 scope and Capabilities 

This is the first of four levels involving improved air filtration. Among 
the four, it is the simplest to apply and requires the least cost and space. 
Any improved air filtration requires a licensed mechanical contractor to 
ensure effective installation and prevent adverse effects on ventilation 
rates 
and HVAC system operation. 

Level 4 involves aerosol filtration only
in the existing air-handling units and
provides a medium level of protection
because the filters are less efficient than
HEPA filters. Also, existing air-handling
units typically allow substantial volumes of
air to bypass the filters. This bypass occurs
not only at the filter-holding frames but
also at leakage paths in the air-handling
unit cabinet under negative pressure.

[text box]
Summary of Capabilities for Level 4
Level 4 improves the protection against
biological and radiological agents and
certain irritants in aerosol form, such as tear gas
and pepper spray.
For these agents, this provides a medium level
of protection against outdoor releases and a
low level of protection against indoor releases.
This level adds no capability to protect against
chemical agents. At this level, sheltering in
place provides capability for protecting against
chemical warfare agents and toxic industrial
chemicals (TICs).
[end text box]



4.4.4.2 Methods and chemical agents. 

This increased level of protection for
aerosols requires:

. Installing filters of higher MERV within available space and within 
resistance limitations of the air-handling unit fan. This is most easily 
accomplished by installing filters of mini-pleat configuration having 
greater filter depth and therefore, greater surface area. 

. Sealing filters to their retaining frames to minimize bypass, and sealing 
leakage paths on the air-handling unit cabinet between the filter 
frames and the fan. 

. Operating at outdoor air fractions that produce a positive internal 
pressure in the building. 

The details of sealing frames vary from installation to installation. 
Generally, front-access filters provide much better potential for reducing 
bypass than do side-access filters, although there are side-access 
housings available with locking mechanisms to ensure a good filter seal. 
Pressurization levels are the same as those discussed for Levels 6 and 7.


4.4.4.3 Cost Considerations 
The costs of modifications to the filter holding frames vary with the type 
and condition of the air-handling unit. 

Additional resistance to flow in terms of pressure drop may result in 
increased operating costs, which are likely to be offset by additional 
service 
life resulting from greater surface area. 

Costs of replacement filters will increase, as will the labor to change 
filters, re-establish effective seals, and dispose of hazardous wastes that 
are characteristic for higher efficiency filters. 

4.4.5 Level 5, gas-Phase Filtration, Medium Level 

4.4.5.1 scope and Capabilities 


The second level of filtration involves the
addition of adsorbers to the HVAC system
to filter chemical agents from recirculated
air and ventilation air. This level produces
substantial protection against a chemical
release either indoors or outdoors;
however, it provides a lower level of
protection against an outdoor release than
Level 7.
Adsorbers for this application are
commercially available and commonly
used in buildings having special indoor air-
quality requirements. As such, the
adsorbers have a relatively low resistance
(pressure drop of around 0.5 to 1 inch,
water gauge) and consequently, a much lower efficiency (initially about
99 percent) and capacity than adsorbers made to the higher standards of
military or Department of Energy specifications.

[text box]
Summary of Capabilities for Level 5
Level 5 applies a medium level of protection
against chemical warfare agents and
against some TICs released outdoors.
It provides a low level of protection against
indoor releases of these chemical agents.
The filtering capability for chemicals of higher
vapor pressure is less than that of Level 7.
This level provides no additional capability for
biological or radiological agents beyond
Level 4.

[end text box]

These adsorbers do not filter agents of higher vapor pressure as well as 
military adsorbers do. Typically, they have coarse granular carbon trays of 
1-inch depth in a V-bed configuration. The units typically have an initial 
bypass of at least 1 percent. There are also adsorbers made of multiple 
layers of pleated, carbon-loaded, non-woven material (see Figure 4-6). 

This capability is best attained with installation of adsorbers in an air-
handling unit or ducted in line. A similar capability can be attained with 
free-standing, floor-mounted units or ceiling-mounted units; however, 
these are less practical in most large commercial buildings in that several 
units may be necessary in each room to provide performance equivalent 
to the units ducted in line or mounted in the air-handling unit. 

Service life of these adsorbers is typically 12 to 18 months; however, 
efficiency diminishes with time in service, to relatively low values within a 
year, reducing the protection provided to low levels later in the service 
life 
period. Manufacturers of the adsorbers provide surveillance testing to help 
determine the frequency of filter replacement. 

Figure 4-6: 9,000-cfm filter un t incorporating pleated adsorbers. 


4.4.5.2 Methods and Requirements 

Adsorber units can be installed by adding an adsorber section 
(approximately 3 feet long) to an air-handling unit, or by adding an 
in-line filter unit in the supply duct. Upgrading the air-handling unit 
fan/motor may be necessary to accommodate the additional airflow resistance 
of 
the adsorbers. 

There are two types of adsorbers, those with granular carbon beds and 
those with carbon pleats consisting of non-woven material loaded with 
fine-mesh carbon granules. Comparison of performance between these 
two types of adsorbers can be made on a carbon-per-cubic feet per minute 
(cfm) basis (usually this is in the range of 0.05 to 0.1 pound per cfm for 
substantial efficiency and capacity). 

Multi-panel housings in which removable flat panels form V-bed 
configurations generally have greater bypass than V-bed cells or pleated 
cartridges. 

4.4.5.3 Cost Considerations 

The installation costs for adsorber units are about $0.50 per cfm. With 
a one-year service life, filter replacement costs are about $0.25 per cfm 
per year. Additional operating energy costs are about one fourth the 
maintenance costs due to the pressure drop of the adsorbers (0.75 inch of 
water gauge). 

4.4.6 Level 6, aerosol Filtration, High Level 

4.4.6.1 scope and Capabilities 

This level is the first of two that involve
very high efficiency filtering of ventilation
air separately from recirculation air. This
level is for aerosol filtration only and is
to be applied in a continuously operating
system, rather than activated upon
detection, because biological agents are
not detectable in real time.


[text box]
Summary of Capabilities for Level 6
For biological or radiological agents,
Level 6 provides the highest possible level of
protection against outdoor releases.
Against an indoor release of biological or
radiological agents, this level does not
improve upon the protection Level 4 provides.
Except for irritant aerosols, this provides no
additional capability for chemical agents
beyond sheltering in place (Levels 2 and 3) or
the adsorbers of Level 5.
[end text box]


4.4.6.2 Methods and Requirements 

beyond sheltering in place (Levels 2 and 3) or 
the adsorbers of Level 5. 

This level involves the installation of a
makeup-air unit with HEPA filters and
an effective sealing system to prevent filter bypass. The makeup-air unit
requires heating and cooling coils to temper the air introduced into the
building before it is further conditioned by the air-handling units.

An ultraviolet germicidal irradiation (UVGI) system of certified 
performance could be used in place of the HEPA filter for disinfection 
of air as it enters the building; however, such systems also require 
mechanical filtration for removal of other aerosols (and to keep lamp and 
reflector surfaces clean). Although there are several UVGI systems on the 
market for use in air-handling units, most do not have the capability for 
high-efficiency disinfection of biological threat agents in air. Some systems 
are intended for surface disinfection, killing mold, bacteria, and fungi on 
cooling coils or drain pans. There is currently no certification process for 
UVGI systems for protection against bio-agent attack. 


Less space is required for Level 6 makeup-air units than Level 7, which 
requires both HEPA filters and high-efficiency adsorbers. Sizing of 
the filtration system in terms of airflow capacity is determined by the 
buildings leakage rate and the square footage of the protected space. 
With normal building construction techniques, leakage is less than 
optimum for pressurization of the building. Desired pressure levels 
in low-rise buildings are 0.1 to 0.2 inch, water gauge, and greater in 
high-rise buildings. Pressurizing a building to these levels usually takes 
substantially more ventilation air than is supplied for health and comfort 
requirements. Table 4-1, below, shows the flow rate of air required per 
square foot of floor area for a 0.1-inch, water gauge pressure. 

The airflow required for pressurization can be determined by fan-
pressurization testing, American Society of Heating, Refrigerating and 
Air-Conditioning Engineers (ASHRAE) tables (ASHRAE, 2004), and tables 
based on previous fan-pressurization tests provided by the manufacturer. 

Table 4-1: Estimated Makeup Airflow Rate per Square Foot (Floor Area) 
to Achieve an Overpressure of 0.1 Inch, Water Gage 


4.4.6.3 Cost Considerations 

This level is relatively high in cost because it requires pressurization of 
the building or selected spaces to ensure that all exchange of indoor and 
outdoor air occurs through the filters. Pressurizing buildings typically 
requires substantial increases in the rate of ventilation air flow, which 
leads to increased heating and cooling costs. 

4.4.7 Level 7, gas-Phase Filtration, High Level 

4.4.7.1 scope and Capabilities 

As with Level 6, this level also involves filtering the ventilation air 
separately from recirculation air at very high efficiency. 
Level 7 involves the installation of high-efficiency gas
adsorbers to filter makeup air for
pressurizing the protected zones, and
thereby expands the high-level protective
capability to toxic gases and vapors.

[text box]
Summary of Capabilities for Level 7
For chemical agents, Level 7 provides a very
high level of protection for filterable chemicals
released outdoors.
This level does not increase the protection against
biological or radiological agents beyond that of
Level 6.
Against an indoor release, this level does not
provide benefit beyond that of Level 5.
[end text box]


Because this level includes HEPA 
filtration in series with the high-efficiency 
adsorber it provides the highest, most 
complete level of protection against an 
outdoor release of chemical, biological, 
or radiological agents. However, it is 
limited in the filtration of some chemical 
agents of higher vapor pressure. 

Generally, chemicals of vapor pressure above 10 millimeters of mercury 
are filtered by chemisorption; that is, carbon is impregnated with salts 
of copper, silver, zinc, and molybdenum, and the gases react with these 
impregnants as they pass through the filter bed to form products that 
are innocuous or retained in the bed. However, the best broad-spectrum 
carbon will not filter all toxic chemicals. The addition of a special 
sorbent, 
mixed or layered in the bed, can add to the filter capability for specific 
gases, but increases the size and resistance of the adsorber. 

Filtering only ventilation air is not effective against an indoor release. 
Protecting against an indoor release requires the internal filtration of 
Levels 4 and 5 or the physical security measures of level 2. 

4.4.7.2 Methods and Requirements 

Among the primary decisions in applying this level of protection is 
whether to protect the whole building or a relatively small selected space. 

This decision is usually based on cost and the need for a high level of 
protection. 

Whole building. In pressurizing the whole building, mechanical rooms are 
generally excluded or divided to exclude furnaces or boilers from the 
protected space. In mechanical rooms containing both air-handling units 
and boilers, the mechanical room is partitioned so that the air-handling 
units are within a pressurized space and the boilers are not. 

Selected space. Spaces usually selected for pressurized, high-level chemical 
protection are security operations centers, emergency operations centers, 
command and control centers, command suites, and safe rooms. A 
safe room with this level of protection is considered a Class I safe room 
(section 4.4.3). 

A second decision regarding the application of Level 7 is whether to 
design a continuously operating system or a standby system. The latter 
may be applied because gas-phase filtration is for chemical agents, which 
can be detected in real time. Therefore, the system can be activated upon 
detecting a release or learning of a heightened threat level. Canister-
type filter systems for use in safe rooms and home shelters are intended 
for standby use; these are hermetically sealed and can retain their full 
capability for at least 10 years. The high-efficiency filtration unit can be 
installed in a mechanical room, on the roof, or at grade inside secure 
fencing. 

Three types of adsorbers commonly used are V-bed, radial-flow, and 
pleated, as shown in Figure 4-7. Installations of radial-flow and V-bed 
adsorbers are shown in Figures 4-8 and 4-9. 


Figure 4-7: Three types of high-efficiency gas adsorbers commonly used (from 
left to right: radial-flow M98 
military adsorber, V-bed adsorber, and multi-layer pleated adsorber). 


Figure 4-8: Radial-flow adsorbers in multiple 1,000-cfm housings n 
a 16,000-cfm system serving a hospital. 


Figure 4-9: A 6,000-cfm V-bed filter un t serving a 12,000 sq ft safe 
room. 


4.4.7.3 Cost Considerations 

Installing, operating, and maintaining systems for ultra-high efficiency gas 
adsorption is very expensive. Installing such a system costs approximately 
$20 
to $100 per square foot. 

The principal maintenance cost is the replacement of filters, the high-
efficiency gas adsorbers, approximately every 3 years. This equates to a 
cost of $2 per year per cfm, or about $0.50 to $1.00 per square foot per 
year. Energy costs for such units are about one-fourth the maintenance 
costs. 

4.5 summary 

Operational Risk-Reduction Measures for CBR 

the following summarizes the operational measures for CBR risk 
reductions: 

. Develop plans, procedures, and training for sheltering in place, 
evacuation, and purging 
. Provide CBR threat awareness and response training to building 
occupants 
. Purchase escape hood respirators for all occupants and provide 
training in their use 
. Secure air intakes, mechanical rooms, and HVAC plenums against 
unauthorized access 
. Perform entry inspections at the building lobby 
. Institute mail-screening procedures 
. Maintain operational security for building plans and building signage 
Building Upgrades for CBR 
. Install single-switch control of all building fans to facilitate sheltering 
in place and purging 
. Install a public-address system to achieve rapid implementation of 
emergency actions 
. Apply sealing measures to tighten selected safe room(s) 
. Install automatic dampers for outside air intakes and exhaust fans to 
facilitate sheltering in place 
. Place recirculation filter units having substantial adsorbers for use in 
safe rooms 
. For safe rooms, install a separate, isolated recirculation system for 
cooling and heating 
. Install and monitor video-surveillance cameras 
. Isolate the lobby, mailroom, cloakroom, and loading dock 
architecturally and mechanically 
. Install filters of greater depth/surface area and higher MERV rating, 
such as MERV 14, 15, or 16 mini-pleats, in air-handling units and seal 
filters and frames to minimize bypass 
. Modify air-handling units to install indoor-air-quality type, low 
resistance adsorbers 



. Install ventilation/makeup-air units with HEPA filtration for each zone 
to be protected 
. Install ventilation/makeup-air units with high-efficiency gas adsorbers, 
as well as HEPA filters for each zone protected 
. Install vestibules or revolving doors for highly protected zones 
. With upgraded air filtration, operate air-handling units at outdoor air 
fractions that produce positive pressures of approximately 0.1 to 0.2 
inch, water gauge, in the building 

4.6 CBR Protection Measures 

The preceding discussions of CBR threat mitigation measures can 
be condensed into the following list. It is presented here as an 
example of measures that might be generated by the FEMA 452 
process and implemented using this document (FEMA 459), as discussed 
in Chapter 2. These measures are all included in the list that comprises 
the vertical axes of the matrices in Section 2.3. 

Level 1, Operational Measures and Expedient Protection 

. Expedient sheltering in place 
. Designating safe rooms, interior rooms having a lower air exchange rate 
. Identifying switches for all air-handling units and fans for deactivation 
. Defining procedures for sheltering and for purging the building after plume 
passage 
. Establishing a building-wide notification system 
. Familiarizing occupants with procedures and responsibilities 
. Evacuation 
. Purging 
. Using escape respirators 

Level 2, Enhanced Physical Security 

. Secure air intakes against unauthorized access 
. Secure mechanical rooms and HVAC plenums against unauthorized access 
. Perform entry inspections 
. Employ video surveillance equipment 
. Institute mail screening procedures 
. Maintain operational security to building plans and signage 
. Apply mechanical and architectural isolation of lobby, mailroom, 
cloakroom, and loading docks 

Level 3, Enhanced Sheltering In Place 

. Install single-switch control of fans for sheltering and purging 
. Tighten the seal for the envelope of the building and selected safe 
room(s) 
. Install automatic dampers for outside air intakes and exhaust fans 
. Implement a public address system to achieve rapid implementation 
of emergency actions 
. Isolate mechanical spaces that require large volumes of outside air 
. Install separate fans and air streams for ventilation and recirculation, 
as well as cooling and heating, of safe rooms 
. Use recirculation filter units in safe rooms 
Level 4, Aerosol Filtration, Medium Level 

. Seal filter frames to minimize bypass 
. Install filters of greater depth/surface area and higher MERV rating 
. Operate at positive internal pressures 

Level 5, Gas-Phase Filtration, Medium Level 

. Install indoor-air-quality type, low-resistance adsorbers 
. Operate at positive internal pressures 
. Install vestibules or revolving doors for highly protected zones 

Level 6, Aerosol Filtration, High Level 

. Install ventilation/makeup-air units with HEPA filtration 
. Install vestibules or revolving doors for highly protected zones 
. Operate at positive internal pressures 

Level 7, Gas-Phase Filtration, High Level 

. Install ventilation/makeup-air units with high-efficiency adsorbers and 
HEPA filtration 
. Install vestibules or revolving doors for the protected zones 
. Operate at positive internal pressures 
All of these measures can be implemented independently with the 
exception of expedient sheltering in place (Level 1). 


FEMA 459 / April 2008 

Risk Management Series 

Incremental Protection for Existing Commercial Buildings from Terrorist 
Attack: Providing Protection to People and Buildings





CHAPTER 5 PRINCIPLES OF DESIGN FOR RISK REDUCTION RELATED TO OPERATIONAL 
SECURITY MEASURES 

Operational security measures for commercial buildings augment the blast and 
CBR physical protective measures by establishing the capability to deter, 
detect, delay, and respond to these threats, as well as other harmful acts. 
Operational security measures encompass the physical security systems, the 
security policies and procedures, and the personnel resources committed to 
protecting commercial buildings. This chapter reviews the range of operational 
security measures available to commercial facilities to counter blast and CBR 
threats and addresses considerations for applying these measures to retail, 
office, and multifamily residential facilities, and hotels. The chapter 
concludes with an examination of the integration of operational and physical 
protective measures, including the relative flexibility of operational 
measures and the resulting tradeoffs during implementation. 

5.1 OVERVIEW OF OPERATIONAL SECURITY MEASURES 

[Begin text box]
Operational Security Measures
. Detect on and Assessment
. Interdict on and Response
. Procedural Measures
. Preparedness Measures 
. Security Master Planning
[End text box]

Operational security measures work in conjunction with blast and CBR 
measures to protect personnel, equipment, and intellectual property. A 
Measures baseline of protective measures established at Measures commercial 
facilities might include locking doors, lighting parking lots, and controlling 
access to small expensive items. Beyond this baseline, additional security 
measures are commonly added to counter specific threats. These measures might 
include procedures as simple as checking the picture and date on an 
identification card. Additional security measures can also include 
sophisticated systems, such as biometric identification, metal detectors, 
video assessment and surveillance systems, armed security personnel, and even 
chemical and radiation detectors. 

Operational security measures can be divided into five basic components: 
detection and assessment measures, interdiction and response measures, 
procedural measures, preparedness measures, and security master planning. 

5.2 DETECTION AND ASSESSMENT MEASURES 

Detection and assessment measures for blast events and CBR threats include 
exterior intrusion detection, interior intrusion detection, CCTV systems, 
access control systems, vehicle inspections, duress alarms, and mail/package 
screening. 

5.2.1 EXTERIOR INTRUSION DETECTION SYSTEMS 

Exterior intrusion detection systems are used to detect an intruder 
crossing the boundary of a protected area. They can also be used in clear 
zones along fences or around buildings or for detecting unauthorized 
access to critical outdoor infrastructure (transformers, water tanks, 
etc.). Generally these systems use infrared, (see Figure 5-1) seismic, 
microwave, or video motion technologies to alert security personnel to 
an encroachment. Because of the nature of the outdoor environment, 
exterior sensors are more susceptible to nuisance and environmental 
alarms than interior sensors. The use of dual technology sensors and a 
proper assessment method is key to an effective system. 

[Begin figure]
Figure 5-1 is a photo showing a doorway with balanced magnetic switch 
and passive infrared motion sensor. 
Source: Terrence Ryan 
[end figure]


5.2.2 INTERIOR INTRUSION DETECTION SYSTEMS 

Interior intrusion detection measures, like exterior systems, are designed 
to detect penetration or attempted penetration through perimeter 
barriers. Interior sensors can be deployed at a facilitys perimeter or 
in an interior space. An interior asset is one contained within a cube 
with sensors protecting all six faces, such as walls, ceilings, and floors, to 
include duct openings, doors, and windows. Tamper protection and access/secure 
mode capabilities should be considered when planning 
interior systems. Interior sensors include: 

. Structural vibration sensors 
. Glass-breakage sensors 
. Passive ultrasonic sensors. Balanced magnetic switches 
. Grid wire sensors 
. Microwave motion sensors 
. Passive infrared motion sensors 
. Dual technology sensors. 
. Video motion sensors 

[Begin text box]
DUAL TECHNOLOGY SENSORS
Dual technology sensors use two technologies in a logical combination to 
reduce false alarms. One example is a combination of 
a microwave sensor and a passive infrared sensor that must activate 
simultaneously to create an alarm. 
[End text box]

5.2.3 VIDEO ASSESSMENT AND SURVEILLANCE SYSTEMS 

Video assessment and surveillance systems may be used to conduct 
access control, surveillance, and video motion detection. Access control 
applications include monitoring building entrances, loading docks, 
and other access points. Surveillance applications include maintaining 
observation over large or concentrated areas, such as site access points, 
parking lots, building perimeters, key interior areas, or points of alarm. 
Video motion detection applications have sensors that generate an alarm 
when an intruder enters a selected portion of a cameras field of view. 
They can be programmed to activate alarms, initiate recording, or prompt 
other designated actions when motion is detected by a security camera. 

. Interior Applications. Alarm assessment, card reader event assessment, 
emergency exit activation assessment, and surveillance of lobbies, 
corridors, and open areas. 

. Exterior Applications. Alarm assessment, individual zones and portal 
assessment, specific paths and areas, exclusion areas, and surveillance 
of activities. 

. Video Motion Detection. Video motion sensors are available on most 
digital video recorders (DVRs) used in security applications. The 
sensor processes and compares successive images against predefined 
alarm criteria. The system usually provides adjustable windows that 
can be positioned to monitor selected points of the video image. Some DVRs can 
be programmed to monitor very specific fields of view for specific types of 
motion in order to increase system effectiveness and minimize extraneous 
detections. 

Video assessment and surveillance systems may be monitored in real time 
or recorded for later viewing (see Figure 5-2). Systems designed for one 
usage may not be optimized for the other. 

[Begin text box]
ADDITIONAL VIDEO ASSESSMENT AND SURVEILLANCE SYSTEMS CONSIDERATIONS 

. Plan camera placement to provide adequate coverage of vehicle and pedestrian 
movements along per meter fence lines, site, roadway and parking lot access 
points, building exteriors, entrances, emergency exits, and utility systems. 

. Use the integration features of modern Pan Tilt Zoom cameras systems to 
point and focus on cues from door contacts and switches, interior motion 
detect on devices, or other sensors. 

. Integrate landscaping efforts with camera placement initiatives. 
Control plantings and tree and shrubbery growth to avoid obstructing camera 
fields of view. 

. Perform a lighting survey to ensure lighting levels are adequate and 
consistent with camera equipment manufacturer specifications. 

. Train staff members on the use (and limitations) of the camera system. 

. Video mot on sensors can greatly improve the efficiency of security 
personnel monitoring security cameras by alerting them when 
mot on s detected. 

[Begin figure]
Figure 5-2 is a photo video assessment and surveillance systems. 
Source: Bob Cizmadia 
[End figure}

5.2.4 ACCESS CONTROL SYSTEMS 

The building layout, rate and flow of employees and visitors, threat 
level, personnel available, and types of technical equipment installed are 
considerations for establishing access control measures. A screening plan 
should be comprehensive to permit authorized personnel to conduct their 
business with minimum delay, but provide access to only those with a 
legitimate need. Access control measures normally consist of a public 
access control area, a walk-through metal detector and/or hand-held 
metal detector, and an entry control system. 

. Public Access Control Area. This allows for identifying and screening of 
visitors before admitting them into restricted areas (see Figure 5-3). 

. Walk-Through Metal Detector and/or Hand-Held Metal Detector. Metal 
detectors are intended to detect the presence of concealed firearms 
or other weapons while avoiding the intrusiveness of individual 
searches or frisking. Additionally, screening may detect the presence 
of concealed electronic devices (such as hidden transmitters) and 
explosive devices having metal components. 

. Entry Control Systems. The function of an entry control system is to 
ensure that only authorized personnel are permitted into or out of 
a controlled area. Entry can be controlled by locked fence gates, 
locked doors to a building or rooms within a building, or specially 
designed portals. Entry control can be enforced physically with guards or 
automatically using entry control devices. For a guard system, guards verify 
that a person is authorized to enter an area, usually by comparing the 
photograph and personal characteristics of the individual requesting entry. 
For an automated system, the entry control device verifies that a person is 
authorized to enter or exit. The automated system usually interfaces with 
locking mechanisms on doors or gates that open momentarily to permit passage. 
All entry control systems control passage using one or more of three basic 
techniques: a Personal Identification Number, a credential, or an identifying 
feature like a fingerprint. Automated entry control devices based on these 
techniques are grouped into three categories: code, credential, and biometric 
devices. 

[Begin figure]
Figure 5-3is a photo of blast effects related to access control. 
Source: Michael Kaminskas 
[End figure]

5.2.5 VEHICLE INSPECTION SYSTEMS 

Vehicle inspection systems employ personnel to examine entering 
vehicles in accordance with predetermined guidelines (see Figure 5-4). 

[Begin figure]
Figure 5-4 is a photo showing an entry control point. 
Source: Terrence Ryan 
[End figure]

Inspections may be appropriate at low and high threat locations. At low 
threat locations, guards may only inspect a vehicle drivers identification or 
a facility parking sticker. At higher threat locations, guards may inspect the 
vehicle and occupants identification, vehicle interior, undercarriage, engine 
compartment, interior, trunk, and gas-fill cover area. Inspections should 
occur as far from critical site facilities as possible (preferably at the site 
perimeter). The inspection area may include vehicle arresting devices that 
prevent vehicles from tailgating or from leaving the inspection area without 
permission. 

5.2.6 DURESS ALARMS 

Duress alarms installed at fixed locations (see Figure 5-5) or carried as 
mobile devices alert security personnel to a potential threat or incident. 
If used outside a defined area, duress alarms should be programmed to 
transmit the precise location of the user. 

5.2.7 MAIL/PACKAGE SCREENING 

Mail and package screening involves controlling and screening the mail 
and packages for contraband, weapons, chemical, biological, radiological, 
or incendiary materials, and other items, whether brought into a facility 
by an individual or by mail/package delivery. Screening technologies 
may detect components of explosive devices or explosive compounds 
by radiographic analysis, by analyzing chemical emissions, or by other 
methods (see Figure 5-6). Radiological detectors, which are accurate, 
reliable, and relatively inexpensive, may also be used. Package screening 
measures may include: 

. Arranging for off-site inspection of mail/packages 
. Centralizing mail/package delivery and screening into a standalone 
building or on the perimeter of the facility 
. Providing explosive detection and response training to mail handlers 
. Conducting X-ray screening of mail and packages 
. Utilizing explosive and CBR detection equipment 

[Begin figure]
Figure 5-5 is a photo showing an emergency phone in parking garage. 
Source: Bob Cizmadia 
[End figure]

[Begin figure]
Figure 5-6: Example of an a r sampling system in a mailroom. 
Source: Terrence Ryan 
[End figure]

5.3 INTERDICTION/RESPONSE MEASURES 

Response/interdiction forces provide a means to delay adversaries while 
protecting personnel and critical locations from blast and CBR events. 
Response force requirements are dependent on contingency planning and range 
from on-site or off-site security guards to local and State police forces. 
Response/interdiction measures include security guard forces with a deterrence 
or delay role, security guard forces with a response/interdiction role, and 
general contingency planning with local and State police. 

Security guard services consist of proprietary or contract guards, or a 
combination of both depending on their purpose, the size of the facility, and 
other factors. Their effectiveness, however, is dependent on the quality of 
the individuals involved. Proper licensing, training, and background checks 
are critical for ensuring each individual response force member is qualified. 

5.3.1 GUARD FORCE  DETECTION/DELAY ROLE 

Guard forces with a detection or delay role generally monitor video 
surveillance equipment, check credentials, and patrol. They may be 
located in a lobby area, a patrol area, or in a security operations center 
connected to several entry points. These security guards perform access 
control functions and surveillance by either direct observation or through 
video surveillance. If an event occurs, they conduct an assessment and 
coordinate the response actions of employees and internal and external 
response forces. They may also respond directly to events if simple 
interdiction may limit the incident or to assist with evacuation and 
isolation. 

For the largest facilities, the security guard may be afforded a protected 
booth with hardened walls, protected egress, pass tray, access denial system, 
CCTV monitors, controls of entrances and exits, radios, telephones, paging 
systems, intercoms, key boxes, indicator and alarm panels, the active vehicle 
barrier override control, security light controls, elevator controls, and 
controls for air-handling systems. 


5.3.2 GUARD FORCE  RESPONSE/INTERDICTION ROLE 

Guard forces with a response/interdiction role are more highly trained 
and responsible for conducting containment and denial actions. Guards 
may be trained and equipped for duties including: delaying at a distance, 
delaying to permit occupants at risk to escape, and finally delayhold 
counterattack. These guards protect personnel, goods, and services, but 
should not be expected to engage in law enforcement activities. 

[Begin text box]
GUARD FORCE ROLES 

. Detection. Mon tor video surveillance equipment, control access, 
and patrol to detect threats. 

. Delay at a Distance. Increase the t me that elapses between the 
detect on of an imminent terrorist attack and the actual onset of 
an attack to perm t the arrival of response forces or the successful 
evacuation of personnel. 

. Delay to Permit Flight. Increase the amount of t me that elapses 
between the onset of an attack and terrorist access to executives to 
perm t the arrival of response forces or the successful evacuation of 
executives under attack. 

. Delay, Hold, and Counterattack. Increase the duration of an attack 
by allowing occupants to remain secure n a safe haven until a 
response force can arrive to repulse the attack, and apprehend the 
terrorists. 
[End text box]


5.3.3 RESPONSE FORCE CONTINGENCY PLANNING 

Conducting contingency planning and documenting procedures are 
critical to an effective response function. Contingency planning involves 
identifying potential intruders and developing response procedures for 
each likely threat. For example, facilities may specify a level of force that 
guards would be expected to use in different scenarios. Contingency 
planning also ensures the availability and redundancy of communication 
systems with both internal and external responders. This increases the 
ability of the guards to receive notification of an event, coordinate their 
internal response, and synchronize the response with outside agencies. 

5.4 PROCEDURAL MEASURES 

Procedural measures are the policies and procedures that limit 
vehicle and pedestrian movement around and within critical 
areas, limit the release of building information, such as plans 
and schematics, and encourage employee support of security programs. 
While most commercial buildings need to provide access for their 
tenants, customers, or the general public, each employee, maintenance 
person, and visitor does not need equal access to every space. Restricted 
areas may protect critical infrastructure or simply keep the public in 
easily observable spaces. Designating and enforcing parking controls are 
procedural measures of special note because of the possible use of vehicle 
bombs by terrorists. 

5.4.1 RESTRICTED AREAS 

Restricted areas are classified as controlled, limited, or exclusion areas, 
depending on the degree of security and control required (see Figure 5-7). 

[Begin figure]
Figure 5-7 is a photo shows an Electronic entry control device into restricted 
area. 
Source: Bob Cizmadia 
[End figure]

Controlled Area. A controlled area is that portion of a restricted area near 
or surrounding a limited or exclusion area. Entry to a controlled area is 
restricted to personnel with a need for access. Movement of authorized 
personnel within this area is not necessarily controlled because entry does 
not provide access to a security interest. The controlled area is provided for 
administrative control, for safety, or as a buffer zone to the in-depth 
security of the limited or exclusion area. 

Limited Area. A limited area is a restricted area near a security interest. 
Uncontrolled movement may permit access to the security interest. Escorts and 
other internal restrictions may prevent access within limited areas. 

Exclusion Area. An exclusion area is a restricted area containing a security 
interest. Uncontrolled movement permits direct access to the security 
interest. 

5.4.2 PARKING AND TRAFFIC CONTROLS 

In general, vehicle parking near buildings should be discouraged due 
to the threat of vehicle bombs. While pre-entry screening of vehicles 
at perimeter entrances will decrease the risk of penetration by vehicle-
borne improvised explosive devices (IED), it does not eliminate this 
hazard. Restricting unscreened vehicles from parking under facilities, 
from parking within a predetermined distance from a building, or from 
traveling into a protected area will increase blast protection. 

In summary, parking and traffic control activities include: 

. Control on-site parking with ID checks, security personnel, and access 
systems (see Figure 5-8) 
. Separate employee and visitor parking 
. Eliminate internal building parking 
. Ensure natural surveillance by concentrating pedestrian activity, 
limiting entrances/exits, and eliminating concealment opportunities 
. Prevent pedestrian access to parking areas other than via established 
entrances 

[Begin figure]
Figure 5-8 is a photo showing Parking control. 
Source: Terrence Ryan 
[End figure]

5.4.3 RESTRICT ACCESS TO FACILITY INFORMATION 

Facility information, including drawings and operational procedures for 
mechanical, electrical, plumbing, structural, and security systems should 
be controlled, and its release should be restricted. 

5.4.4 ENCOURAGE EMPLOYEE SUPPORT 

Procedural measures require that employees be motivated to support 
the security program. Regardless of the security measures employed, 
if employees do not follow operational policies and procedures, 
vulnerabilities will persist. An appropriate corporate climate, adequate 
operational planning, and established management objectives will help 
encourage employees to support security measures. 

5.5 PREPAREDNESS MEASURES 

Preparedness measures are actions taken to increase readiness 
for a crisis, mitigate impacts, and respond to and recover from 
an incident. These include disaster preparedness planning, 
conducting risk assessments, developing mass notification warning 
systems, evacuation planning, preparing to shelter in place, monitoring 
systems and resources, and conducting training exercises. 

[Begin text box]
PREPAREDNESS MEASURES 

. Develop a Disaster Preparedness Plan preparedness plan. 
. Conduct Risk Assessments 
. Develop Mass Notification Systems 
. Conduct Evacuation Planning and Shelter in Place Preparation 
. Mon tor Systems and Resources 
. Conduct Training Drills and Exercises 

More information on disaster preparedness is available at the FEMA Web site: 
www.fema.gov/plan/index.shtm 
[End text box]

5.5.1 DEVELOP A DISASTER PREPAREDNESS PLAN 
Protecting facilities begins with developing a disaster The FEMA Web site 
provides numerous links and examples of plans that can be tailored to fit your 
facility. The risk assessment, as well as identification of mitigation 
measures to minimize or prevent losses, provides the basis for developing the 
plan. 

5.5.2 CONDUCT RISK ASSESSMENTS 

Risk assessments are conducted to assess threat/hazards, impacts on assets, 
vulnerabilities to incidents, and subsequent risks. Security countermeasures 
should be defined and prioritized relative to their impact on risk. 

5.5.3 DEVELOP MASS NOTIFICATION SYSTEMS 

Mass notification systems, such as automatic messaging or public address 
systems, should be developed to reach all building occupants. These systems 
should provide warning and alert information, along with actions to take 
before and after an incident. System and electric power redundancy 
should be ensured. 

5.5.4 EVACUATION PLANNING AND SHELTER IN PLACE PREPARATION 

The building occupants should be prepared for independent action 
prior to the arrival of emergency responders. This preparation involves 
evacuation planning and shelter in place preparation. The building 
occupants should also be trained on the Incident Command System 
in order to understand the chain of command, available integrated 
communications, and management of resources throughout the recovery. 

5.5.5 MONITOR EMERGENCY SYSTEMS AND RESOURCES 

Systems and resources intended to support the facility during a crisis 
should be monitored to ensure their availability and function. Examples 
of such systems and resources include, but are not limited to: 

. Emergency equipment and critical utilities 
. Fire alarms and detection and suppression systems 
. Emergency resources and vendors (e.g., fuel for emergency generators) 
. Alternate worksites 
. Updated maps and floor plans 
. System backups and off-site storage 

5.5.6 CONDUCT TRAINING DRILLS AND EXERCISES 

Training drills and exercises help to improve efficiency of emergency 
response teams and employees, clarify responsibilities, reveal weaknesses, 
and reduce stress. A commitment to testing also lends credibility and 
authority to the security program. 

In summary, training involves: 

. Rehearsing emergency plans with local law enforcement 
. Conducting joint exercises with first responders 
emergency management 

[Begin text box]
Complete information on the management of various emergency events 
and the Inc dent Command System s available from the FEMA Web site: 
www.fema.gov/emergency/n ms/index.shtm 
[End text box]

5.6 SECURITY MASTER PLANNING

All of these operational security measures should be guided by the 
final component, a Security Master Plan (see Figure 5-9). This 
3-to 5-year plan, based on the goals of the overall organization, 
states the vision, goals, and objectives of the security program. The plan 
should also outline the operational security measures, the path for the 
security program to keep pace with the changing threat environment, and 
future initiatives. Further, it should be integrated into the organizations 
facility planning process as well as benchmarked against the security programs 
of similar facilities. 

[Begin figure]
Figure 5-9 is a photo showing how Security Master Planning integrates the 
operational security measures into the organizations facility planning 
process. 
Source: Terrence Ryan 
[End figure]

A comprehensive Security Master Plan should: 

. Be communicated and disseminated to all levels of management and 
building occupants as appropriate 
. Be integrated into the facility construction or renovation planning 
. Be benchmarked or compared to related facilities 
. Be tested and evaluated 
. Identify threats/hazards, assets, vulnerabilities, and risks 
. Establish a security improvement implementation schedule 
. Establish a security operating and capital budget 
. Follow regulatory or industry guidelines/standards 

5.7 ADDITIONAL ASPECTS OF OPERATIONAL SECURITY MEASURES RELATED TO BLAST 
EVENTS 

[begin text box
ADDITIONAL OPERATIONAL SECURITY MEASURES FOCUSED ON BLAST EVENTS
. Establish an explosive detect on program 
. Establish bomb threat procedures 
. Establish blast-related ma l/package handling procedures 
[End text box]

Tactics for developing and employing IEDs are continuing to evolve. 
Fortunately, responses to IED threats are also rapidly changing as 
technologies and procedures to detect and mitigate the terrorist leave-behind 
IED, human-carried IED, and vehicle-borne IED threats progress. Evolving 
countermeasure technologies are designed to provide time- sensitive 
information that security forces, critical asset managers, police/bomb squads, 
and incident commanders need to detect and counter IEDs away from critical 
infrastructure and personnel. 

Additional operational security measures related to blast events include 
establishing an explosive detection program, establishing bomb threat 
procedures, and establishing blast-related mail/package handling procedures. 

5.7.1 ESTABLISH AN EXPLOSIVE DETECTION PROGRAM 

The effectiveness of an explosive detection program is dependent on 
the level of sophistication of the detection measures. At the low end, 
bomb detection is conducted by inspection. Higher levels of protection 
are achieved using detection equipment, such as X-ray devices, metal 
detectors, and explosive detectors. Explosive detection dogs are an 
alternative to explosive detection technology. 

5.7.2 ESTABLISH BOMB THREAT PROCEDURES 

The following procedures should be followed when receiving a 
telephoned bomb threat: 

. Get as much information from the caller as possible. Ask the following 
questions, if possible: 
	When is the bomb going to explode? 
	Where is it right now? 
	What does it look like? 
	What kind of bomb is it? 
	What will cause it to explode? 
	Did you place the bomb?
	Why? 
	What is your address? 
	What is your name? 

. Keep the caller on the line and record the conversation. 

. Notify the police and building management. 

5.7.3 ESTABLISH BLAST-RELATED MAIL/PACKAGE HANDLING PROCEDURES 

Over the years, postal inspectors have identified typical characteristics of 
suspicious parcels. In many cases the packages: 

. Are unexpected or from someone unfamiliar 

. Have no return address or have one that cannot be verified as 
legitimate 

. Have protruding wires or aluminum foil, strange odors, or stains 

. Show a city or State in the postmark that doesnt match the return 
address 

. Are of unusual weight given their size or are lopsided or oddly shaped 

. Are marked with threatening language 

. Have inappropriate or unusual labeling 

. Have excessive postage or packaging material, such as masking tape 
and string 

. Have misspellings of common words 

. Are addressed to someone no longer with your organization or are 
otherwise outdated 

. Have incorrect titles or titles without a name 

. Are not addressed to a specific person 

. Have hand-written or poorly typed addresses 

5.8 ADDITIONAL ASPECTS OF OPERATIONAL SECURITY MEASURES RELATED TO CBR EVENTS 

When protecting and responding to an accidental hazardous material release or 
an intentional CBR attack on a commercial building, focus operational security 
measures on personnel and vehicle access points, storage areas, the roof, 
mechanical areas, outdoor air intakes, and water utility feeds. The 
operational security needs of each building should be individually assessed, 
as the threat from a nearby hazardous material release or an actual CBR attack 
will vary considerably from building to building (Figure 5-10). Some 
operational security measures are low cost, such as locking doors to 
mechanical rooms or water utility pits, and can be implemented in retail, 
office, and multifamily residential buildings. Other operational security 
measures, such as personnel and package searches by X-ray or explosive 
detection equipment, are expensive and may substantially inconvenience 
businesses. Measures should be implemented as warranted after careful 
consideration of the likelihood of an incident and the resulting consequences. 

[Begin figure]
Figure 5-10 is an illustration showing projected plumes of CBR incident. 
Source: Michael Kaminskas 
[End figure

[Begin text box]
ADDITIONAL OPERATIONAL SECURITY MEASURES FOCUSED ON CBR EVENTS 

. Restrict access, and secure and monitor outdoor air intakes 
. Light, secure, and monitor utility access points 
. Secure and monitor exterior mechanical/electrical spaces 
. Secure and monitor interior HVAC access points 
. Provide internal first responders appropriate hazardous materials 
equipment 
. Restrict access to facility and utility drawings 
. Prevent unauthorized access and monitor roof areas 
. Establish CBR related mail/package handling procedures 
[End text box]?
5.8.1 PREVENT ACCESS, AND SECURE AND MONITOR OUTDOOR AIR INTAKES 

A contaminant could quickly spread throughout the building by the 
HVAC system. Air intakes that are publicly accessible and at or below 
ground level are at the most risk due to ease of approach, as well as 
characteristics of many CBR agents that cause them to remain close to 
the ground. Relocating or extending the air intakes upward can prevent 
access. Creating a restricted area to prevent public access, but allow access 
for authorized personnel can also improve security. Fencing or similar see-
through barriers are preferred to allow visual detection of abnormal activity 
or a deposited CBR source. Security lighting should be provided for outdoor 
air intakes and other accessible points of the HVAC system, which should also 
be monitored with CCTV cameras. Intrusion detection sensors programmed to 
activate alarms, redirect surveillance cameras, and initiate recording should 
also be installed. 

5.8.2 ESTABLISH CBR-RELATED MAIL/PACKAGE HANDLING PROCEDURES 

Additional measures to mitigate the dangers from suspicious envelopes 
and packages with potential CBR agents include: 

. Refraining from eating or drinking in a designated mail handling area 
. Placing suspicious envelopes or packages in a plastic bag or some 
other type of container to prevent leakage of contents 
. Avoiding sniffing or smelling suspect mail 
. Covering the envelope or package with anything available (e.g., 
clothing, paper, or trash can) 
. Leaving the room and closing the door and/or sectioning off the area 
to prevent others from entering 
. Washing your hands with soap and water to prevent spreading any 
contaminants to your face 
. Reporting the incident to your building security official or an available 
supervisor, who will notify authorities without delay 
. Listing all people who were in the room or area when this suspicious 
letter or package was recognized to help local public health authorities and 
law enforcement officials with follow-up investigations 
and advice 

5.8.3 ADDITIONAL MEASURES 

Additional measures to mitigate the potential spread of CBR agents 
through plumbing, mechanical, and electrical systems include: 

. Hardening and locking incoming water service line junction points 
and service pits by installing intrusion detection sensors on the access 
points for all site utilities. 
. Providing security lighting and monitoring on-site stored water and 
associated junction points with CCTV systems (Figure 5-11). 

[Begin figure]
Figure 5-11 is a photo showing an exterior video camera for monitoring 
critical utilities. 
Source: Bob Cizmadia 
[End figure]

. Conducting perimeter surveys to identify mechanical, plumbing, and 
electrical rooms with exterior doors, windows, and utility openings. 
Hardening and locking the doors. Providing grills or louvers for 
all windows and man-passable openings in exterior walls below the 
second floor. (Openings greater then 96 square inches are considered 
man-passable.) Installing intrusion detection sensors on the access 
points. 

. Securing exterior mechanical spaces and equipment. Identifying 
external mechanical spaces and equipment that are publicly accessible 
and establishing a means for direct surveillance, or monitoring with 
intrusion detection equipment and CCTV systems. 

. Securing interior HVAC access points, such as return-air grills. 
Identifying the return-air grills that are publicly accessible and 
establishing a means for direct surveillance, or monitoring with 
intrusion detection equipment and CCTV systems. Removing or 
relocating furniture that obscures surveillance or provides access to 
the return air grills. 

. Providing internal first responders access to appropriate hazardous 
materials response equipment. Required items, such as a hazardous 
material suit, gloves, boots, and a protective hood, may be packaged 
together for convenience. 

. Restricting access to mechanical, plumbing, and electrical systems 
by outside maintenance personnel. Providing escorts for outside 
maintenance personnel that have not been pre-screened or are not 
from a trusted provider. 

. Restricting access to facility and utility drawings and schematics. 

. Preventing unauthorized access and monitoring facility roofs, which 
can provide access to HVAC systems, air intakes, and exhaust vents. 
Establishing fencing or barriers to restrict access from adjacent roofs. 
Locking and monitoring roof access doorways. Providing grills or 
louvers to man-accessible openings. 

5.9 PRIORITIZATION OF OPERATIONAL SECURITY CONSIDERATIONS 

Commercial buildings range in function from retail to office to 
multi-family facilities and hotels. They can be free-standing, 
strip mall, or multi-story structures, and have one occupant or 
thousands. These characteristics vary depending on whether building is 
located in a rural setting, a suburban setting, or a large urban area. The 
following general guidance is provided to protect retail, office, and 
multifamily 
apartment buildings, and hotels. 

5.9.1 RETAIL BUILDINGS 

Retail buildings are openly accessible to the public. This limits some of 
the operational physical security measures that can be applied. Physical 
hardening of the critical infrastructure may be implemented to address 
this limitation. However, even in these buildings, operational security 
measures can be applied: 

. Restricted areas can be established for mechanical rooms, loading 
docks, roofs, and air vents. 

. Interior and exterior CCTV systems may be established both for loss 
prevention and security detection. 

. Anti-ram, landscaping, and other vehicle barriers may be established 
to mitigate the vehicle-borne IED threat. 

. Certain detection and delay measures, such as visitor screening and 
access control, may not be practical during business hours. However, 
after business hours, all intrusion detection measures can be activated. 

. Most procedural, preparedness, and master planning measures can 
be applied. Of these, rehearsing emergency plans with local law 
enforcement and conducting joint exercises with first responders 
are especially important because they contribute to a coordinated 
response in an incident. 

5.9.2 OFFICE BUILDINGS 

Office buildings usually have a circulation plan and procedures that 
permit greater control over visitors compared to retail facilities. This 
facilitates the use of the full range of the operational security measures to 
protect offices from blast and CBR attacks. Based on the risk assessment for 
an office building, effective physical security measures to deter, delay, 
detect, and interdict/respond may be established. All procedural, 
preparedness, and master planning measures, as appropriate, may also be 
applied. 

5.9.3 Multi-Family Apartment Buildings 

A range of operational security measures is available for use in multifamily 
apartment buildings. Emergency preparedness plans and occupant 
education may be the most important life savers in the event of an attack. 
Measures should include: 

. Reviewing and updating emergency preparedness plans 

. Providing education and training to occupants on evacuation 
procedures and identifying and reporting suspicious activity 

Installing suitable hardware to lock doors and windows (delay measures) 
and using a remotely monitored alarm system (detection and interdiction/ 
response measures) may also be useful in rented or leased spaces. 

5.9.4 HOTEL SECURITY MEASURES 

Operational security measures, similar to those for the other types of 
commercial buildings, may be established to protect a hotel from blast- 
and CBR-related events. Interior and exterior video surveillance systems 
may be established for loss prevention and security detection. Access 
to mechanical rooms, loading docks, roofs, and air vents should be 
restricted. Visitor screening and access control can be established during 
nighttime hours. 

Most procedural, preparedness, and master planning measures can 
also be applied. Of these, rehearsing internal emergency plans and 
establishing a liaison with local law enforcement and other first 
responders are especially important because they contribute to a 
coordinated response in an incident. 

5.10 INCREMENTAL INTEGRATION OFOPERATIONAL AND PHYSICAL SECURITY MEASURES INTO 
A RISK REDUCTION PROGRAM: FLEXIBILITYAND TRADEOFFS 

Providing both an open, business-friendly environment and a 
safe and secure facility involves a delicate balance. Many diverse 
technologies are available to meet the security needs of a specific 
facility. The following flexibility and tradeoff considerations will help in 
the selection of incremental operational security measures. 

Balance program improvements. Incremental increases in security 
should be implemented program-wide, with balanced deterrence, 
delay, detection and assessment, and interdiction/response measures. 

Randomly implemented technology may only have a limited impact on 
risk reduction. For example, establishing electronic security systems on 
the doors and not the windows of a facility does not significantly improve 
security. Similarly, establishing a hardened, gated vehicle entrance that 
can be bypassed by driving across a lawn does not appreciably improve 
protection from vehicle bombs. Facility owners should plan incremental 
improvements that decrease the level of risk and increase the overall level of 
protection. 

Use technology to improve detection effectiveness. Having a guard watching 
a bank of CCTV monitors without technology cueing systems usually 
limits detection. The integration of sensors with a CCTV system greatly 
increases the security effectiveness and the area that can be covered. 
Replacing or supplementing security guards with centralized monitoring 
station technology, rather then adding more personnel to monitor simple 
CCTV systems, may be a cost-effective incremental improvement. 

Internet Protocol (IP)-based systems may provide flexibility and eliminate 
the need to integrate with other renovation projects. The rapid shift away 
from the classic, analog-only CCTV solutions to digital encoding and IP 
or network transport over open system connections presents existing 
building owners with new improvement opportunities. The installation 
of IP-based electronic security systems does not require the disruptive 
installation of long individual cable runs back to a central console. IP-
based systems can generally be installed independent of major facility 
renovations. 

Wireless systems may increase flexibility. In the past, installation of 
traditional wired external cameras or intrusion detection systems required 
thousands of dollars in installation costs and business disruptions 
from digging up roadways or parking lots to bury cables. This type of 
improvement had to be linked to other scheduled major renovations. 
Now, with IP-based systems and wireless links, installation may be less 
expensive and less disruptive, and can be completed independent 
of other scheduled renovations. However, wireless systems are more 
accessible to outsiders than wired systems and require appropriate 
protection, such as encryption, firewalls, and passwords to prevent 
hacking and tampering. 

Not all hardware and software applications are compatible. Many proprietary 
systems cannot be integrated with other systems. They may also preclude future 
upgrades or the introduction of new capabilities. Facility managers should 
carefully project requirements and the necessary components of a complete 
system and plan for incremental improvements accordingly. 

Plan the implementation of variable security measures. After establishing 
a baseline of protection, facility managers must be able to increase 
their protective posture in response to an increased threat. While many 
physical measures have long lead times (like applying fragment retention 
film on windows), many operational security measures do not require 
major capital improvement and can be quickly modified as needed. The 
practiced and proven capability to implement variable security measures, 
such as closing underground parking, screening visitors, or limiting 
access, may provide facilities with the alternative of continuing operations 
rather than doing nothing or closing during periods of increased threat. 

Install a high profile security measure early in the improvement sequence to 
publicly highlight increased security. If a facility has several equally 
effective improvements, schedule the high profile items, such as gated entry 
into the loading dock area or a public access control system, early to 
increase the public perception of security. 

5.11 OPERATIONAL SECURITY PROTECTION MEASURES 

The operational security measures identified in the preceding 
discussions are listed below as an example of measures that might 
be generated by the FEMA 452 process and implemented using this document, as 
discussed in Chapter 2. The measures are categorized into those that include 
physical protection and strengthening measures (5.11.1), and those that are 
entirely operational (5.11.2). The former are all included in the list that 
comprises the vertical axes of the matrices in Section 2.3. 

5.11.1 PHYSICAL PROTECTION AND STRENGTHENING BUILDINGS 

1. Operational security measures related to blast and CBR events 
. Detection and assessment measures 
. Exterior intrusion detection systems 
. Interior intrusion detection systems 
. Video assessment and surveillance systems 
. Access control systems 
. Duress alarms 
. Interdiction/response measures 
 . Guard force: detection/delay role 

2. Additional operational security measures related to blast events 
. None. 

3. Additional operational security measures related to CBR Events 
. Restrict access and secure and monitor outdoor air intakes 
. Light, secure, and monitor water service access points 
. Install intrusion detection sensors for all utility services to the building 
. Secure and monitor exterior mechanical spaces and equipment 
. Secure and monitor interior HVAC access points 

These measures can be implemented independently from one another. 

5.11.2 OPERATIONAL MEASURES 

1. Operational security measures related to blast and CBR events 
. Detection and assessment measures 
 . Exterior intrusion detection systems 
 . Interior intrusion detection systems 
 . Video assessment and surveillance systems 
 . Access control systems 
 . Vehicle inspection systems 
 . Duress alarms 
 . Mail/package screening procedures 
. Interdiction/response measures 
 . Guard force: detection/delay role 
 . Guard force: response/interdiction role 
 . Response force contingency planning 
. Procedural measures 
 . Restricted areas: controlled areas 
 . Restricted areas: limited areas 
 . Restricted areas: exclusion areas 
 . Parking and traffic controls: separate employee and visitor parking 
 . Parking and traffic controls: eliminate internal building parking 
 . Parking and traffic controls: ensure natural surveillance 
 . Parking and traffic controls: limit pedestrian access to parking areas 
 . Restrict access to facility information 
 . Encourage employee support 
. Preparedness measures 
 . Develop a disaster preparedness plan 
 . Conduct risk assessments 
 . Develop mass notification systems 
 . Conduct evacuation planning and shelter in place preparation 
 . Monitor emergency systems and resources 
 . Conduct training drills and exercises 
. Security master planning measures 
 . Communicate and disseminate security master plan 
 . Integrate into the facility construction or renovation planning 
 . Benchmark or compare to related facilities 
 . Test and evaluate the plan 
 . Identify threats/hazards, assets, vulnerabilities, and risks 
 . Establish security improvement implementation schedule 
 . Establish security operating and capital budget 

2. Additional operational security measures related to blast events 
. Establish an explosive detection program 
. Establish bomb threat procedures 
. Establish mail/package handling procedures 

3. Additional operational security measures related to CBR events 
. Restrict access to, secure, and monitor outdoor air intakes 
. Light, secure, and monitor water service access points 
. Install intrusion detection sensors for all utility services to the building 
. Secure and monitor exterior mechanical spaces and equipment 
. Secure and monitor interior HVAC access points 
. Provide first responders appropriate hazardous materials equipment 
. Restrict access to critical utility drawings 
. Prevent unauthorized access to and monitor roof areas 
. Establish CBR-related mail/package handling procedures 

All of these measures can be implemented independently from one another. 

5.11.3 OPERATIONAL MEASURES CATEGORIZED INTO THE BUILDING VULNERABILITY 
ASSESSMENT CHECKLIST
 
The following list of operational mitigation measures reorganizes the 
preceding list (5.11.2) into the 13 sections of the Building Vulnerability 
Assessment Checklist in Appendix A of FEMA 452. Where applicable, 
the references in parentheses below refer to the respective sections in 
Chapters 4 and 5 where the item is discussed. 

1. Site 
1.1 Vehicle inspections (5.2.5) 
1.2 Guard force, detection/delay role (5.3.1) 
1.3 Guard force, response/interdiction role (5.3.2) 
1.4 Parking and traffic controls (5.4.2) 
1.4.1 Control on-site parking 
1.4.2 Separate employee and visitor parking 
1.4.3 Eliminate internal building parking 
1.4.4 Ensure natural surveillance 
1.4.5 Limit pedestrian access to parking areas 

2. Architectural 
2.1 Expedient sheltering in place (4.4.1.2) 
2.1.1 Designating safe rooms, interior rooms having a lower air exchange rate 
2.1.2 Identifying switches for all air handling units and fans for 
deactivation 
2.1.3 Defining procedures for sheltering and for purging the building after 
plume passage 
2.1.4 Establishing a building-wide notification system 
2.1.5 Familiarizing occupants with the procedures and responsibilities 
2.2 Evacuation (4.4.1.2) 
2.3 Using escape respirators (4.4.1.2) 
2.4 Enhanced physical security (4.4.2.2) 
2.4.1 Perform entry inspections 
2.4.2 Employ video surveillance equipment 
2.4.3 Institute mail screening procedures 
2.4.4 Maintain operational security to building plans and signage 
2.5 Mail/package screening (5.7.3, 5.8.2) 
2.6 Restricted areas (5.4.1) 
2.6.1 Controlled areas 
2.6.2 Limited areas 
2.6.3 Exclusion areas 
2.7 Prevent unauthorized access to and monitor roof areas 
(5.8.4) 

3. Structural Systems 

4. Building Envelope 

5. Utility Systems (water, sewer, fuel, electrical service, telephone, fire 
alarm) 

6. Mechanical Systems (HVAC) 
6.1 Purging (expedient sheltering in place (4.4.1.2)) 

7. Plumbing and Gas Systems 

8. Electrical Systems 

9. Fire Alarm Systems 

10. Communications and Information Technology Systems 
10.1 Expedient sheltering in place 
10.1.1 Defining building-wide notification system 
10.2 Develop mass notification systems (5.5.3) 

11. Equipment Operations and Maintenance 
11.1 Provide first responders appropriate hazardous materials equipment 
(5.8.4) 

12. Security Systems (perimeter security, interior security, security system 
documents) 

13. Security Master Plan 
13.1 Detection and assessment measures 
13.1.1 Vehicle inspection systems (5.2.5) 
13.1.2 Mail/package screening procedures (5.2.7) 
13.2 Interdiction/response measures 
13.2.1 Response force contingency planning (5.3.3) 
13.3 Procedural measures 
13.3.1 Restrict access to facility information (5.4.3) 
13.3.2 Encourage employee support (5.4.4) 
13.4 Preparedness measures 
13.4.1 Develop disaster preparedness plan (5.5.1) 
13.4.2 Conduct risk assessments (5.5.2) 
13.4.3 Conduct evacuation planning and shelter in place preparation (5.5.4) 
13.4.4 Monitor emergency systems and resources (5.5.5) 
13.4.5 Conduct training drills and exercises (5.5.6) 
13.5 Security master planning measures (5.6) 
13.5.1 Communicate and disseminate 
13.5.2 Integrate into the facility construction or renovation planning 
13.5.3 Benchmark or compare to related facilities 
13.5.4 Test and evaluate the plan 
13.5.5 Identify threats/hazards, assets, vulnerabilities, and risks 
13.5.6 Establish security improvement implementation schedule 
13.5.7 Establish security operating and capital budget 
13.6 Additional operational security measures related to blast events 
13.6.1 Establish an explosive detection program (5.7.1) 
13.6.2 Establish bomb threat procedures (5.7.2) 
13.6.3 Establish mail/package handling procedures (5.7.3) 
13.7 Additional operational security measures related to CBR events 
13.7.1 Restrict access to critical utility drawings (5.8.4) 

These security enhancement operational increments can be implemented 
at any time, as they do not entail physical work in the building. 


BiBLiOgRaPHY 

American Concrete Institute (ACI), 2005. ACI 318-05, Building Code 
Requirements for Structural Concrete and Commentary, ACI Committee 318, 
2005. 

American Society of Heating, Refrigerating and Air-Conditioning 
Engineers (ASHRAE), 2004. ASHRAE Handbook  HVAC Systems and 
Equipment, ASHRAE, Inc., Atlanta, GA, January 2004. 

ASHRAE, 2004. Homeland Security for Buildings, ASHRAE Satellite 
Broadcast, ASHRAE, Inc., Atlanta, GA, April 14, 2004. 

American Society for Industrial Security (ASIS) International, 2000. 
Protection of Assets Manual, ASIS International, Alexandria, VA, www. 
protectionofassets.com. 

ASIS International, 2005. ASIS Business Continuity Guideline: A Practical 
Approach for Emergency Preparedness, Crisis Management, and Disaster 
Recovery, ASIS International, Alexandria, VA, 
www.asisonline.org/guidelines/guidelinesbc.pdf. 

American Society for Testing and Materials (ASTM), 2003. ASTM F 224803, 
Standard Practice for Specifying an Equivalent 3-Second Design Loading for 
Blast Resistant Glazing Fabricated with Laminated Glass, ASTM International, 
West Conchohocken, PA, August 10, 2003. 

Blewett, W.K., and Arca, V.J., 1999. Experiments in Sheltering in Place: How 
Filtering Affects Protection Against Sarin and Mustard Vapor, AD A365348, 
U.S. Army Chemical Biological Center, Aberdeen Proving Ground, MD, June 1999. 

Blewett, W.K., et al., 1996. Sheltering in Place: An Evaluation for the 
Chemical Stockpile Emergency Preparedness Program, AD A370441, U.S. Army 
Chemical Biological Center, Aberdeen Proving Ground, MD, May 1996. 

Blewett, W.K., 2002. Fail-Safe Application and Design of Air Conditioners 
for NBC Collective Protection Systems, ECBC-TR-223, U.S. Army Chemical 
Biological Center, Aberdeen Proving Ground, MD, February 2002. 

Centers for Disease Control and Prevention (CDC) and National Institute 
for Occupational Safety and Health (NIOSH), 2002. Guidance for Protecting 
Building Environments from Airborne Chemical, Biological, or Radiological 
Attacks, Atlanta, GA, www.cdc.gov/niosh/bldvent/2002-139.html. 

Department of the Army, 1996. Expedient Sheltering In Place: An Evaluation 
for the Chemical Stockpile Emergency Preparedness Program, ERDEC-TR-336. 

U.S. Army Edgewood Research, Development and Engineering Center, 
Aberdeen Proving Grounds, MD, June 1996. Department of the Army, 2001. Field 
Manual 3-19.30, Physical Security, www.
army.mil/usapa/doctrine/Active_FM.html. 

Department of Defense, 2003. UFC 4-010-01 Unified Facilities Criteria 
(UFC) DoD Minimum Antiterrorism Standards for Buildings, www.wbdg.org/ 
references/pa_dod.php. 

Department of Health and Human Services, National Institute for 
Occupational Safety and Health (NIOSH), 2002. Guidance for Protecting 
Building Environments from Airborne Chemical, Biological, or Radiological 
Attacks, Publication No. 2002-139, May 2002. 

Department of Health and Human Services, NIOSH, 2003. Guidance 
for Filtration and Air-Cleaning Systems to Protect Building Environments from 
Airborne Chemical, Biological, or Radiological Attacks, Publication No. 
2003136, April 2003. 

Department of State, 2003. Specification for Vehicle Crash Test of Perimeter 
Barriers and Gates, Revision A, SD-STD-02.01, Washington, DC, 
https://pdc.usace.army.mil/library/BarrierCertification. 

Federal Emergency Management Agency (FEMA), 2003. Reference Manual 
to Mitigate Potential Terrorist Attacks Against Buildings, Publication 426, 
FEMA, Washington, DC, www.fema.gov/plan/prevent/rms/rmsp426. 
shtm. 

FEMA, 2003. Incremental Seismic Rehabilitation of School Buildings (K12), 
Publication 395, FEMA, Washington, DC, www.fema.gov/plan/prevent/ 
rms/rmsp395.shtm. 

FEMA, 2005. A How-To Guide to Mitigate Potential Terrorist Attacks Against 
Buildings, Publication 452, FEMA, Washington, DC, 
www.fema.gov/plan/prevent/rms/rmsp452.shtm. 

FEMA, 2006a. Design Guidance for Safe Rooms and Shelters, Publication 453, 
FEMA, Washington, DC, www.fema.gov/plan/prevent/rms/rmsp453.
shtm.

FEMA, 2006b. Bomb Threat, FEMA, Washington, DC, www.fema.gov/
hazard/terrorism/exp/exp_threat.shtm.

FEMA, 2006c. Suspicious Packages and Letters, FEMA, Washington, DC, www.
fema.gov/hazard/terrorism/exp/exp_parcels.shtm.

FEMA, 2007. Site Urban Design for Security: Guidance Against Potential 
Terrorist Attacks, Publication 430, FEMA, Washington, DC, 
www.fema.gov/library/viewRecord.do?id=3135.

Fennelly, Lawrence J., 1999. Handbook of Loss Prevention and Crime 
Prevention, Stoneham, MA, Butterworth-Heinemann, ISBN: 0-7506-9703-2.

Fennelly, Lawrence J., 2004. Effective Physical Security, Third Edition, 
Burlington, MA, Elsevier Inc., ISBN: 0-7506-7767-8.


Garcia, Mary Lynn, 2001. The Design and Evaluation of Physical Protection 
Systems, Stoneham, MA, Butterworth-Heinemann, ISBN: 0-7506-7367-2.
General Services Administration, 2002. Facilities Standards for 
Public Buildings Service, PBS-P100, General Services Administration, 
Washington, DC, www.gsa.gov/Portal/gsa/ep/channelView.
do?pageTypeId=8195&channelId=-15012.

General Services Administration, 2005. Facilities Standards for the Public 
Buildings Service, PBS-P100-2005, General Services Administration, 
Washington, DC, www.gsa.gov/Portal/gsa/ep/channelView.
do?pageTypeId=8195&channelId=-14201.

Kovacich-Halizobek, 2003. The Managers Handbook for Corporate Security, 
Butterworth-Heinemann, Woburn, MA, pp. 186-206.

Lawrence Berkeley National Laboratory (LBNL), 2003. Protecting Buildings 
from Biological or Chemical Attack: actions to be taken before or during a 
release, Publication 51959, January 10, 2003. 

Patterson, David G. III, CPP, CFE, CHS, 2004. Implementing Physical 
Protection Systems: A Practical Guide, USA, ASIS International, ISBN: 
1-887056-58-0. 

Purpura, Philip P., 2002. Security and Loss Prevention, An Introduction, 
Fourth Edition, Woburn, MA, Butterworth-Heinemann, ISBN: 0-7506-7437-7. 

Smilowitz, Robert, 2005. Designing to Resist Explosive Threats, prepared for 
the National Institute of Building Sciences, 2005. 

Smilowitz, Robert, 2005. Retrofits to Resist Explosive Threats, prepared for 
the National Institute of Building Sciences, 2005. 

U.S. Air Force, 2003. Entry Control Facilities Design Guide, www. afcee. 
brooks.af.mil/dc/dcproducts/products.asp. 

U.S. Army Corps of Engineers, 1999. Design of Collective Protection 
Shelters to Resist Chemical, Biological, and Radiological (CBR) Agents, 
Engineer Technical Letter 1110-3-498, Washington, DC, 24 February 1999. 
U.S. Army Corps of Engineers, 2001. Protecting Buildings and Their 
Occupants from Airborne Hazards (draft), Technical Instruction 853-01, 
October 2001. 

U.S. Army Corps of Engineers, 2005. Security Engineering: Procedures for 
Designing Airborne CBR Protection for Buildings (draft), UFC 4-024-01, 4 
February 2005. 

[end of FEMA 459]