Next-Generation 

Performance-Based 

Seismic Design Guidelines 

Program Plan for New and Existing Buildings

FEMA-445 / August 2006

FEMA nehrp

FEMA 445 / August 2006 

Next-Generation PerformanceBased Seismic Design 

Guidelines Program Plan for New and Existing Buildings 

Prepared by 

APPLIED TECHNOLOGY COUNCIL 

201 Redwood Shores Parkway, Suite 240 

Redwood City, California 94065 

www.ATCouncil.org 

Prepared for 

FEDERAL EMERGENCY MANAGEMENT AGENCY 

Department of Homeland Security (DHS) 

Michael Mahoney, Project Officer 

Washington, D.C. 
Notice 

Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily 

reflect the views of the Department of Homeland Security’s Federal Emergency Management Agency 

(FEMA) or the Applied Technology Council (ATC). Additionally, neither ATC, DHS, FEMA, nor any 

of their employees makes any warranty, expressed or implied, nor 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. 

Cover photograph is provided courtesy of Forell/Elsesser Engineers, Inc., San Francisco. 
FEMA 445 Foreword iii 

Foreword

One of the primary goals of the Department of Homeland Security’s Federal Emergency Management 

Agency (FEMA) is prevention or mitigation of this country's losses from hazards that affect the built 

environment. To achieve this goal, we as a nation must determine what level of performance is expected 

from our buildings during a severe event, such as an earthquake, blast, or hurricane. To do this, FEMA 

contracted with the Applied Technology Council (ATC) to develop next-generation performance-based 

seismic design procedures and guidelines, which would allow engineers and designers to better work with 

stakeholders in identifying the probable seismic performance of new and existing buildings. These 

procedures could be voluntarily used to: (1) assess and improve the performance of buildings designed to 

a building code “life safety” level, which would, in all likelihood, still suffer significant structural and 

nonstructural damage in a severe event; and (2) more effectively meet the performance targets of current 

building codes by providing verifiable alternatives to current prescriptive code requirements for new 

buildings. 

This FEMA 445 Program Plan builds on earlier plans developed for FEMA by the Earthquake 

Engineering Research Institute, and the Earthquake Engineering Research Center. As a basis for this 

plan, FEMA 349 (EERI, 2000) provided a description of the key activities necessary for developing 

performance-based seismic design criteria, and FEMA 283 (EERC, 1996) emphasized the research that 

would be required. 

This Program Plan is based on the results of a workshop soliciting the input of the nation's leading 

seismic professionals in preparing a long-term plan to develop new performance-based seismic design 

procedures. It does an excellent job of capturing the recommendations from that workshop and 

describing the necessary requirements. Execution of the plan, however, is contingent upon funding, and 

FEMA had concerns regarding the availability of funding at the levels necessary to achieve the ambitious 

goals outlined in the plan. As a result, FEMA and ATC developed a reduced scope and extended 

schedule under which the program could proceed with less than full funding. This Program Plan includes 

the projected costs for both the original and modified-scope programs. 

Publication of this Program Plan does not obligate FEMA or any other federal agency to any portion of the 

plan contained herein. The information and opinions contained in this Program Plan are solely those of the 

project participants, and do not necessarily represent the views of FEMA. 

FEMA wishes to express its sincere gratitude to all who were involved in this project and in the development 

of this Program Plan. The result of their hard work and dedication will play an important role in helping the 

nation move towards performance-based seismic design and reducing losses suffered by the citizenry in future 

earthquakes. 

—Federal Emergency Management Agency 

FEMA 445 Preface v 

Preface

Advancement of present-generation performance-based seismic design procedures is widely recognized in 

the earthquake engineering community as an essential next step in the nation’s drive to develop resilient, 

loss-resistant communities. This Program Plan offers a step-by-step, task-oriented program that will 

develop next-generation performance-based seismic design procedures and guidelines for structural and 

nonstructural components in new and existing buildings. 

This FEMA 445 Program Plan is a refinement and extension of two earlier FEMA plans: FEMA 283 

Performance-Based Seismic Design of Buildings – an Action Plan, which was prepared by the Earthquake 

Engineering Research Center, University of California at Berkeley in 1996, and FEMA 349 Action Plan 

for Performance Based Seismic Design, which was prepared by the Earthquake Engineering Research 

Institute in 2000. The state of practice for performance-based assessment, performance-based design of 

new buildings, and performance-based upgrades of existing buildings will all be significantly advanced 

under this Program Plan. 

The preparation of this Program Plan, and developmental work completed to date, has been performed by 

the Applied Technology Council (ATC) under the ATC-58 project entitled Development of NextGeneration Performance-Based Seismic Design Guidelines for New and Existing Buildings. The 

technological framework developed under this program is transferable and can be adapted for use in 

performance-based design for other extreme hazards including fire, wind, flood, and terrorist attack. The 

decision-making tools and guidelines developed under this Program Plan will greatly improve our ability 

to develop cost-effective and efficient earthquake loss reduction programs nationwide. 

Christopher Rojahn, ATC Executive Director 

FEMA 445 Acknowledgments vii 

Acknowledgments

This FEMA-445 Program Plan was prepared by the Applied Technology Council under FEMA contract 

EMW-2001-CO-0378. Ronald O. Hamburger, Project Technical Director, was the principal architect of 

the Program Plan and is the principal author of this report. Substantial contributions were also made by 

the Product Development Team Leaders and their teams, with review and input by the Project 

Management Committee, and the Project Steering Committee. 

The Project Management Committee consisted of Christopher Rojahn (Chair), Ronald O. Hamburger 

(Co-Chair), Peter J. May, Jack P. Moehle, Maryann T. Phipps (ATC Board Representative), and Jon 

Traw. The Structural Products Development Team consisted of Andrew Whittaker (Team Leader), 

Gregory Deierlein, Andre Filiatrault, John Hooper, and Andrew T. Merovich. The Nonstructural 

Performance Products Team consisted of Robert E. Bachman (Team Leader), David Bonowitz, Philip J. 

Caldwell, Andre Filiatrault, Robert P. Kennedy, Gary McGavin, Eduardo Miranda, and Keith Porter. The 

Risk Management Products Team consisted of Craig D. Comartin (Team Leader), Brian J. Meacham 

(Associate Team Leader), C. Allin Cornell, and Charles Kircher. Project Steering Committee members 

consisted of William T. Holmes (Chair), Daniel P. Abrams, Deborah B. Beck, Randall Berdine, Roger D. 

Borcherdt, Jimmy Brothers, Michel Bruneau, Terry Dooley, Mohammed Ettouney, John Gillengerten, 

William J. Petak, Randy Schreitmueller, and James W. Sealy. Jon A. Heintz served as Report Editor, and 

Peter N. Mork produced the camera-ready document. The affiliations of these individuals are provided in 

the list of project participants at the end of this report. 

Input to this Program Plan was provided by a broad range of earthquake engineering specialists during a 

FEMA-sponsored workshop conducted by ATC in February 2003. Participants included researchers and 

practicing structural engineers as well policy makers and regulators. The sage advice provided by these 

individuals substantially influenced the direction and scope of this Program Plan. 

The vision, insight, and patience provided by the FEMA Project Officer, Michael Mahoney, and the 

FEMA Technical Monitor, Robert D. Hanson, are also gratefully acknowledged. 

FEMA 445 Executive Summary ix 

Executive Summary

The Applied Technology Council (ATC), under the sponsorship of the Department of Homeland 

Security’s Federal Emergency Management Agency (FEMA), is currently engaged in a project to 

advance the state of practice in performance-based seismic design. This report, FEMA 445 Program Plan, 

offers a step-by-step, task-oriented program that will develop next-generation performance-based seismic 

design procedures and guidelines for structural and nonstructural components in new and existing 

buildings. The preparation of this Program Plan, and developmental work completed to date, has been 

performed under the ATC-58 project entitled Development of Next-Generation Performance-Based 

Seismic Design Guidelines for New and Existing Buildings. 

This Program Plan offers background on current code design procedures, introduces performance-based 

seismic design concepts, identifies improvements needed in current seismic design practice, and outlines 

the tasks and projected costs for a two-phase program to develop next-generation performance-based 

seismic design procedures and guidelines. This plan is a refinement and extension of two earlier FEMA 

plans: FEMA 283 Performance-Based Seismic Design of Buildings – an Action Plan, which was prepared 

by the Earthquake Engineering Research Center, University of California at Berkeley in 1996, and FEMA 

349 Action Plan for Performance Based Seismic Design, which was prepared by the Earthquake 

Engineering Research Institute in 2000. 

Building Code Procedures for Seismic Design 

Building codes establish minimum requirements for safety through the specification of prescriptive 

criteria that regulate acceptable materials of construction, identify approved structural and nonstructural 

systems, specify required minimum levels of strength and stiffness, and control the details of how a 

building is to be put together. Although these prescriptive criteria are intended to result in buildings 

capable of providing certain levels of performance, the actual performance of individual building designs 

is not assessed as part of the traditional code design process. As a result, the performance capability of 

buildings designed to these prescriptive criteria can be better than the minimum standards anticipated by 

the code, while the performance of others could be worse. 

Performance-based Design 

Performance-based seismic design explicitly evaluates how a building is likely to perform, given the 

potential hazard it is likely to experience, considering uncertainties inherent in the quantification of 

potential hazard and uncertainties in assessment of the actual building response. It permits design of new 

buildings or upgrade of existing buildings with a realistic understanding of the risk of casualties, 

occupancy interruption, and economic loss that may occur as a result of future earthquakes. 
x Executive Summary FEMA 445 

It also establishes a vocabulary that facilitates meaningful discussion between stakeholders and design 

professionals on the development and selection of design options. It provides a framework for 

determining what level of safety and what level of property protection, at what cost, are acceptable to 

building owners, tenants, lenders, insurers, regulators and other decision makers based upon the specific 

needs of a project. 

In contrast to prescriptive design approaches, performance-based design provides a systematic 

methodology for assessing the performance capability of a building, system or component. It can be used 

to verify the equivalent performance of alternatives, deliver standard performance at a reduced cost, or 

confirm higher performance needed for critical facilities. 

First-generation procedures introduced the concept of performance in terms of discretely defined 

performance levels with names intended to connote the expected level of damage: Collapse, Collapse 

Prevention, Life Safety, Immediate Occupancy, and Operational Performance. They also introduced the 

concept of performance related to damage of both structural and nonstructural components. Performance 

Objectives were developed by linking one of these performance levels to a specific level of earthquake 

hazard. Although intended for existing buildings, these procedures are being extrapolated for use in the 

performance-based design of new buildings. 

The Need for Next-Generation Procedures 

As the state of knowledge and experience base advances, limitations in present-generation procedures are 

being identified by researchers and practitioners. These include questions regarding the accuracy of 

analytical procedures in predicting actual building response, questions regarding the level of conservatism 

present in acceptance criteria, the inability to reliably and economically apply performance-based 

procedures to the design of new buildings, and the need for alternative ways of communicating 

performance to stakeholders that is more meaningful and useful for decision-making purposes. Nextgeneration performance-based design procedures are needed to: 

• Revise the discrete performance levels defined in first-generation procedures to create new 

performance measures (e.g. repair costs, casualties, and time of occupancy interruption) that better 

relate to the decision-making needs of stakeholders, and that communicate these losses in a way that 

is more meaningful to stakeholders. 

• Create procedures for estimating probable repair costs, casualties, and time of occupancy interruption, 

for both new and existing buildings. 

• Develop a framework for performance assessment that properly accounts for, and adequately 

communicates to stakeholders, limitations in our ability to accurately predict response, and 

uncertainty in the level of earthquake hazard. 

Framework for Next-Generation Procedures 

The next-generation performance-based seismic design procedures developed under this Program Plan 

will express performance directly in terms of quantified risks that a building owner or decision maker will 
FEMA 445 Executive Summary xi 

be able to understand. Stakeholders prefer to define these risks in terms of the potential for casualties, 

repair costs, and occupancy interruption. Stakeholder guidance will be developed to assist decision 

makers in selecting appropriate levels of risk as the basis of design and upgrade projects. Engineering 

guidelines will be prepared to assist design professionals in developing building designs that are reliable 

and capable of meeting the selected risk criteria. 

Program Plan 

Work under this Program Plan is divided into two phases: 

• Phase 1: Developing a Methodology for Assessing the Seismic Performance of Buildings. In this 

phase, a methodology will be developed for assessing the probable seismic performance of individual 

buildings in future earthquakes. 

• Phase 2: Developing Performance-Based Seismic Design Procedures and Guidelines. In this phase, 

seismic design procedures and guidelines will be developed to assist engineers in designing buildings 

to meet desired performance goals, and to assist stakeholders in taking advantage of the benefits of 

performance-based design. 

Work in each phase is organized around six broad categories of work: Planning and Management Program; 

Structural Performance Products; Nonstructural Performance Products; Risk Management Products; 

Guidelines Products; and Stakeholders Guide Products. Work in each technical area will be performed by 

one of three Product Development Teams, consisting of the Structural Performance Products Team, the 

Nonstructural Performance Products Team, and the Risk Management Products Team. 

Planning and Management Program tasks will be carried out within a project management structure 

consisting of three committees: Project Management Committee, Project Technical Committee, and 

Project Steering Committee. Collectively, these committees provide management, technical oversight, 

and control of the work performed by the three Product Development Teams. 

Projected Costs and Schedule 

As originally planned, the total projected project costs of Phase 1 and 2 of this Program Plan are 

estimated to be approximately $21 million in 2004 dollars. Estimates of personnel and other costs were 

developed using prevailing labor costs common to projects of this type at the time this plan was prepared, 

and do not include escalation due to changes in the value of money, labor rates, internal government 

costs, or inflation. Phase 1 has a projected cost of approximately $11 million, and Phase 2 has a projected 

cost of approximately $10 million. At this funding level, each phase will last approximately five years, 

and the work of Phase 1 will be substantially complete before Phase 2 begins. 

Since available funding was not adequate to support the full Program Plan, a reduced scope and extended 

schedule was developed under which the program could proceed with less than full funding. Projected 

costs for the modified-scope program are approximately 50% of those for the original program. Each 

phase is planned to be accomplished in approximately five to seven years, and Phase 1 has been 

underway for four years. Phase 2 is planned to begin upon completion of Phase 1. 

FEMA 445 Contents xiii 

Contents

Foreword........................................................................................................ iii 

Preface..............................................................................................................v 

Acknowledgements....................................................................................... vii 

Executive Summary ....................................................................................... ix 

List of Figures............................................................................................. xvii 

List of Tables ............................................................................................... xix 

1. Introduction.........................................................................................1 

 1.1 General...................................................................................1 

 1.2 Current Building Code Procedures for Seismic Design.........1 

 1.3 Performance-Based Seismic Design ......................................3 

 1.4 Advantages of Performance-Based Seismic Design ..............5 

 1.5 First-Generation Performance-Based Procedures..................6 

 1.6 Present Second-Generation Performance-Based 

Procedures..............................................................................7 

 1.7 The Need for Next-Generation Performance-Based 

Procedures..............................................................................7 

1.8 Framework for Next-Generation Performance-Based 

Procedures and Relationship to HAZUS ...............................8 

2. Program Plan: Goals, Background, Organization, 

and the Performance-Based Design Process.....................................11 

 2.1 Program Goals .....................................................................11 

 2.2 Program Background ...........................................................11 

 2.3 Preparatory Work from 2001 to Date ..................................12 

 2.4 Program Organization..........................................................14 

 2.5 Performance-Based Seismic Design Process.......................17 

 2.5.1 Step 1: Select Performance Objectives ...................17 

 2.5.2 Step 2: Develop Preliminary Building Design........19 

 2.5.3 Step 3: Assess Performance....................................19 

 2.5.4 Step 4: Revise Design.............................................21 

 2.6 Applicability of Performance-Based Design to Other 

Structural Hazards................................................................22 

3. Phase 1: Developing a Methodology for Assessing the Seismic 

Performance of Buildings .................................................................23 

 3.1 Phase 1 Objectives ...............................................................23 

 3.1.1 Expandable Framework ..........................................23 

 3.1.2 Research Needed From Other Programs.................24 
xiv Contents FEMA 445 

 3.2 Phase 1 Organization........................................................... 25 

 3.3 Phase 1 Project Management .............................................. 23 

 3.3.1 Project Management Committee............................ 26 

 3.3.2 Project Technical Committee ................................. 27 

 3.3.3 Project Steering Committee ................................... 27 

 3.4 Summary of Phase 1 Technical Tasks................................. 28 

 3.4.1 Structural Performance Products Tasks ................. 28 

 3.4.2 Nonstructural Performance Products Tasks ........... 29 

 3.4.3 Risk Management Products Tasks ......................... 30 

 3.5 Phase 1 Projected Program Costs and Schedule ................. 31 

4. Phase 1: Developing a Methodology for Assessing the 

Seismic Performance of Buildings—Technical Tasks ..................... 35 

 4.1 Phase 1 Structural Performance Products Tasks ................. 35 

 4.1.1 Structural Input to Performance 

Assessment Guidelines (SPP-1) ............................. 36 

 4.1.2 Identify Structural Engineering 

Demand Parameters (SPP-2).................................. 37 

 4.1.3 Identify Intensity Measures (SPP-3) ...................... 38 

 4.1.4 Prepare Analysis Guidelines (SPP-4)..................... 39 

 4.1.5 Identify Structural Damage Measures (SPP-5) ...... 40 

 4.1.6 Structural Input to Model 

Building Studies (SPP-6) ....................................... 41 

 4.1.7 Develop Procedures for Input 

to Nonstructural Evaluation (SPP-7)...................... 42 

 4.1.8 Develop Structural Loss Functions (SPP-8)........... 43 

 4.2 Phase 1 Nonstructural Performance Products Tasks........... 43 

 4.2.1 Nonstructural Input to Performance 

Assessment Guidelines (NPP-1) ............................ 44 

 4.2.2 Develop Catalog of Nonstructural 

Components and Systems (NPP-2) ........................ 44 

 4.2.3 Identify Nonstructural Performance 

Measures (NPP-3) .................................................. 45 

 4.2.4 Identify Input Engineering 

Demand Parameters (NPP-4) ................................. 46 

 4.2.5 Develop Performance Database (NPP-5)............... 46 

 4.2.6 Develop Nonstructural Performance 

Evaluation Protocols (NPP-6)................................ 47 

 4.2.7 Simplify Nonstructural Engineering 

Demand Parameters (NPP-7) ................................. 47 

 4.2.8 Develop Procedures for Computing 

Nonstructural Damage (NPP-8) ............................. 48 

 4.2.9 Develop Nonstructural Loss Functions (NPP-9).... 49 

 4.2.10 Nonstructural Input to Model 

Building Studies (NPP-10)..................................... 49 

 4.3 Phase 1 Risk Management Products Tasks ......................... 49 

 4.3.1 Develop Input to Performance 

Assessment Guidelines (RMP-1) ........................... 51 

 4.3.2 Develop Structural Loss Functions (RMP-2)......... 51 

 4.3.3 Develop Nonstructural Loss Functions (RMP-3)... 52 
FEMA 445 Contents xv 

 4.3.4 Develop Model for Aggregating 

Losses (RMP-4) ......................................................53 

 4.3.5 Formulate Conceptual Aggregation 

Procedures (RMP-5) ...............................................55 

 4.3.6 Procedure for Aggregating Local Effects 

to Global (RMP-6)..................................................56 

 4.3.7 Develop Loss Integration Procedures (RMP-7)......56 

 4.3.8 Identify Stakeholder Needs (RMP-8) .....................57 

 4.3.9 Develop Standard Performance 

Level Characterizations (RMP-9)...........................59 

5. Phase 2: Developing Performance-Based Seismic Design 

Procedures and Guidelines................................................................61 

 5.1 Phase 2 Objectives ...............................................................61 

 5.2 Phase 2 Description of Work ...............................................62 

 5.3 Summary of Phase 2 Product Tasks.....................................62 

 5.3.1 Structural Performance Products Tasks ..................63 

 5.3.2 Nonstructural Performance Products Tasks............63 

 5.3.3 Risk Management Products Tasks..........................64 

 5.4 Phase 2 Project Management ...............................................65 

 5.5 Phase 2 Projected Program Costs and Schedule ..................65 

6. Phase 2: Developing Performance-Based Seismic Design 

Procedures and Guidelines—Product Tasks.....................................69 

 6.1 Phase 2 Structural Performance Products Tasks..................69 

 6.1.1 Identify Structural Contribution 

to Performance (SPP-9) ..........................................70 

 6.1.2 Identify Effect of Structural 

Parameters (SPP-10) ...............................................70 

 6.1.3 Identify Preferred Structural Strategies 

for New Buildings (SPP-11)...................................71 

 6.1.4 Identify Preferred Structural Upgrade 

Strategies (SPP-12).................................................71 

 6.1.5 Provide Input to Design Guidelines (SPP-13) ........71 

 6.2 Phase 2 Nonstructural Products Tasks.................................72 

 6.2.1 Identify Nonstructural Performance 

Contributions (NPP-11) ..........................................73 

 6.2.2 Identify Effectiveness of 

Current Practice (NPP-12) ......................................74 

 6.2.3 Identify Effectiveness of 

Alternative Strategies (NPP-13) .............................75 

 6.2.4 Identify Preferred Strategies (NPP-14)...................75 

 6.2.5 Provide Input to Design Guidelines (NPP-15)........76 

 6.3 Phase 2 Risk Management Products Tasks..........................76 

 6.3.1 Identify Key Performance 

Concerns (RMP-10)................................................77 

 6.3.2 Identify Key Performance 

Parameters (RMP-11) .............................................79 

 6.3.3 Identify Preferred Decision-Making 

Models (RMP-12)...................................................80 

 6.3.4 Develop Simplified Decision Tools (RMP-13) ......80 
xvi Contents FEMA 445 

 6.3.5 Evaluate Performance Capability 

of Buildings Conforming to Current 

Codes (RMP-14) .................................................... 81 

 6.3.6 Evaluate Performance Capability of 

Typical Existing Buildings (RMP-15) ................... 82 

 6.3.7 Develop Stakeholder Guides (RMP-16) ................ 83 

 6.3.8 Provide Input to Design Guidelines (RMP-17)...... 83 

Appendix A: Seismic Performance Assessment ......................................... 85 

 A.1 Performance-Based Design Process.................................... 85 

 A.2 Performance Assessment Process ....................................... 87 

 A.3 Characterization of Ground Shaking Hazard ...................... 88 

 A.4 Structural Analysis and Structural Response Functions...... 91 

 A.5 Formation of Nonstructural Response Functions................ 95 

 A.6 Evaluation of Structural Fragilities ..................................... 96 

 A.7 Development of Nonstructural Fragilities......................... 101 

 A.8 Evaluation of Structural and Nonstructural Loss 

Functions........................................................................... 102 

 A.9 Predicting Loss as a Function of Damage......................... 102 

Appendix B: Example Application of Seismic Performance 

Assessment Using Numerical Integration Techniques...... 105 

Appendix C: Example Application of Seismic Performance 

Assessment Using Closed Form Solutions........................ 119 

References ................................................................................................... 123 

Project Participants...................................................................................... 129 
FEMA 445 List of Figures xvii 

List of Figures

Figure 1-1 Performance-based design flow diagram...............................4 

Figure 2-1 Performance-based design process as it relates 

to Phase 1 and Phase 2 of the Program Plan........................17 

Figure 3-1 Project management structure..............................................26 

Figure 3-2 Summary of tasks and schedule for Phase 1: 

Developing a Methodology for Assessing the Seismic 

Performance of Buildings ....................................................32 

Figure 4-1 Phase 1: Schedule for structural performance 

products tasks.......................................................................36 

Figure 4-2 Phase 1: Schedule for nonstructural performance 

products tasks.......................................................................44 

Figure 4-3 Phase 1: Schedule for risk management product tasks ........51 

Figure 4-4 Loss aggregation process .....................................................54 

Figure 5-1 Summary of tasks and schedule for Phase 2: Developing 

Performance-Based Seismic Design Procedures and 

Guidelines............................................................................66 

Figure 6-1 Phase 2: Schedule for structural performance products 

tasks .....................................................................................68 

Figure 6-2 Phase 2: Nonstructural Performance Products task 

schedule ...............................................................................73 

Figure 6-3 Phase 2: Schedule for Risk Management Products tasks.....75 

Figure A-1 Performance-based design flow diagram.............................86 

Figure A-2 Performance assessment process .........................................82 

Figure A-3 Scenario-based hazard function for hypothetical 

building site and earthquake scenario..................................89 

Figure A-4 Scenario-based hazard function for site using Cartesian 

coordinates...........................................................................89 

Figure A-5 Probability distribution for structural response, 

expressed as interstory drift ratio for a particular 

structure and ground shaking intensity ................................92 
xviii List of Figures FEMA 445 

Figure A-6 Cumulative probability distribution for structural 

response expressed as interstory drift ratio for a 

particular structure and ground shaking intensity ............... 93 

Figure A-7 Hypothetical structural response function for building....... 93 

Figure A-8 Illustrative nonstructural component demand function 

for floor response acceleration at 0.5 second ...................... 95 

Figure A-9 Illustrative nonstructural component response 

acceleration hazard curve.................................................... 96 

Figure A-10 Example fragility function for beam-column 

connection behavior .......................................................... 100 

Figure A-11 Example fragility function for building-wide structural 

behavior............................................................................. 100 

Figure A-12 Hypothetical fragility curve for exterior cladding............. 102 

Figure A-13 Hypothetical loss curve for repair cost of damaged 

beam-column connections................................................. 103 

Figure A-14 Hypothetical loss curve for fatalities, given collapse........ 104 

Figure B-1 Hazard Curve with intensity at 10% chance of 

exceedance in 50 years indicated ...................................... 107 

Figure B-2 Response curve for hypothetical structure ........................ 108 

Figure B-3 Cumulative probability distribution for interstory 

drift response, conditioned on the 10%/50 year 

scenario event.................................................................... 110 

Figure B-4 Fragilities for local damage to steel moment frame 

connection assemblies....................................................... 111 

Figure B-5 Fragilities for global damage to steel moment frame 

building ............................................................................. 111 

Figure B-6 Probability of Experiencing Various Repair Costs as 

Function of Connection Assembly Damage State............. 115 

Figure C-1 Median Hazard Curve for Site .......................................... 120 

Figure C-2 Global fragility for hypothetical structure......................... 121 

Figure C-3 Structural response curve for hypothetical building ......... 121 
FEMA 445 List of Tables xix 

List of Tables

Table 3-1 Original Projected Costs by Product Development 

Area, Phase 1: Development of Performance 

Assessment Guidelines ........................................................33 

Table 3-2 Original Projected Program Costs by Task and 

Year ($1,000); Phase 1.........................................................33 

Table 3-3 Reduced-Scope Projected Costs by Product 

Development Area, Phase 1: Development of 

Performance Assessment Guidelines ...................................34 

Table 3-4 Reduced-Scope Projected Program Costs by 

Task and Year ($1,000); Phase 1 .........................................34 

Table 4-1 Phase 1: Schedule for Structural Performance 

Product Tasks.......................................................................36 

Table 5-1 Original Projected Program Costs by Product 

Development Area, Phase 2: Development of 

Performance-Based Seismic Design Guidelines..................67 

Table 5-2 Original Phase 2 Projected Program Costs by Task and 

Year ($1,000).......................................................................67 

Table 5-3 Reduced-Scope Projected Program Costs by Product 

Development Area, Phase 2: Development of 

Performance-Based Seismic Design Guidelines..................68 

Table 5-4 Reduced-Scope Phase 2 Projected Program Costs by 

Task and Year ($1,000) .......................................................68 

Table B-1 Peak Ground Acceleration for 10%/50 Year Event, at 

Various Confidence Levels................................................107 

Table B-2 Central Value of PGA for Scenario Event within 

Confidence Bands..............................................................109 

Table B-3 Distribution of Interstory Drift for the 10%/50 – Year 

Event ..................................................................................109 

Table B-4 Calculation of Probability of Each Local Damage State ...112 

Table B-5 Calculation of Probability of Each Global Damage 

State, Given the 10% - 50 Year Event ...............................114 
xx List of Tables FEMA 445 

Table B-6 Calculation of Probable Repair Cost, Given that a 

Connection Damage State is Experienced......................... 115 

Table B-7 Calculation of Probable Repair Costs for Global 

Damage ............................................................................. 117 

Table B-8 Calculation of Expected Repair Cost, Given 

10%/50-Year Event........................................................... 118 

Table C-1 Epistemic and Aleatory Uncertainty for Example 

Building............................................................................. 122 
FEMA 445 1: Introduction 1 

Chapter 1

Introduction

1.1 General 

This report, FEMA 445 Program Plan, has been prepared to guide the 

development of next-generation performance-based seismic design 

procedures and guidelines applicable to new and existing buildings. It sets 

forth objectives, tasks, recommended budgets, and a schedule to be used as a 

basis for the execution of a project that builds on existing concepts for 

performance-based seismic design, and formulates a framework for a nextgeneration methodology. Work under this plan is being performed for the 

Department of Homeland Security’s Federal Emergency Management 

Agency (FEMA) by the Applied Technology Council (ATC) under the ATC58 project, Development of Next-Generation Performance-Based Seismic 

Design Guidelines for New and Existing Buildings. 

Chapter 1 offers background on current code design procedures, 

performance-based seismic design, and improvements needed in current 

seismic design practice. Chapter 2 discusses project goals and organization. 

Chapters 3 and 4 present the basic work plan for implementing Phase 1, 

which will develop guidelines for improved procedures to assess the 

probable seismic performance of buildings. Chapters 5 and 6 present the 

work plan for implementing Phase 2, which will develop recommended 

performance objectives and guidelines for assisting engineers and 

stakeholders in implementing the performance-based design process. 

Appendix A describes the technical details of the framework for nextgeneration seismic performance assessment, and introduces terms discussed 

in this Program Plan that may be less familiar to earthquake professionals 

who are not structural reliability or seismic risk specialists. Appendices B 

and C offer alternative numerical examples for implementing these 

procedures. 

1.2 Current Building Code Procedures for Seismic Design 

Design and construction in the United States is generally regulated at the 

state or local level using codes based on national model building codes and 

standards. When adopted and enforced by local authorities, building codes 

are intended to establish minimum requirements for providing safety to life 

and property from fire and other hazards (ICC, 2006). 
2 1: Introduction FEMA 445 

This goal is accomplished through the specification of prescriptive criteria 

that regulate acceptable materials of construction, identify approved 

structural and nonstructural systems, specify required minimum levels of 

strength and stiffness, and control the details of how a building is to be put 

together. Prescriptive requirements are based on broad classifications of 

buildings and occupancies, and are typically stated in terms of fixed values 

such as fire resistance ratings, allowable area and height, and specifications 

related to structural design (e.g., dead loads, live loads, snow loads, rain 

loads, earthquake loads, wind loads, etc.). 

Although the prescriptive criteria of model building codes are intended to 

result in buildings capable of providing certain levels of performance, the 

actual performance capability of individual building designs is not assessed 

as part of the traditional code design process. As a result, the performance 

capability of buildings designed to prescriptive criteria can be variable and, 

for a given building, may not be specifically known. The performance of 

some buildings designed to these prescriptive criteria can be better than the 

minimum standards anticipated by the code, while the performance of others 

could be worse. 

The development of seismic design criteria is an ongoing process of 

improvement. The evolution of seismic design provisions in model building 

codes can be tracked against the occurrence of damaging earthquakes, both 

in the United States and abroad. Earthquakes in the early part of the 20th

century (e.g. the 1925 Santa Barbara and 1933 Long Beach earthquakes) led 

to the development of regulations to provide for minimum levels of lateral 

strength. In the latter part of the 20th century earthquakes such as the 1971 

San Fernando Earthquake led to the realization that, in addition to strength, 

buildings needed to have the ability to deform without catastrophic failure (a 

characteristic known as ductility). 

Building owners and occupants generally believe that adherence to building 

codes provides for a safe and habitable environment, and anticipated degrees 

of damage are not a normal consideration for owners and most design 

professionals. Experience in earthquakes at the end of the 20th century (e.g. 

the 1994 Northridge and 1995 Kobe Earthquakes) has forced recognition that 

damage, sometimes severe, can occur in buildings designed in accordance 

with the code. Property and insured losses as a result of the Northridge 

Earthquake, recognized as the most costly earthquake in U.S. history, led to 

an awareness that the level of structural and nonstructural damage that could 

occur in code-compliant buildings may not be consistent with public notions 

of acceptable performance. 
FEMA 445 1: Introduction 3 

Changes in the state of knowledge and the evolution of seismic design 

criteria have also led to changes in engineering practice and research. With 

an emphasis on providing stakeholders the information needed to make 

rational business or safety-related decisions, practice has moved toward 

predictive methods for assessing potential seismic performance. At the same 

time researchers have been working on the development of new analytical 

tools and test data needed to improve assessment techniques. Recognition 

that code-based strength and ductility requirements applicable for the design 

of new buildings are not suitable for the evaluation and upgrade of existing 

buildings has led to the development of performance-based engineering 

methods for seismic design. 

1.3 Performance-Based Seismic Design 

The performance-based seismic design process explicitly evaluates how a 

building is likely to perform, given the potential hazard it is likely to 

experience, considering uncertainties inherent in the quantification of 

potential hazard and uncertainties in assessment of the actual building 

response. 

In performance-based design, identifying and assessing the performance 

capability of a building is an integral part of the design process, and guides 

the many design decisions that must be made. Figure 1-1 shows a flowchart 

that presents the key steps in the performance-based design process. It is an 

iterative process that begins with the selection of performance objectives, 

followed by the development of a preliminary design, an assessment as to 

whether or not the design meets the performance objectives, and finally 

redesign and reassessment, if required, until the desired performance level is 

achieved. 

Performance-based design begins with the selection of design criteria stated 

in the form of one or more performance objectives. Each performance 

objective is a statement of the acceptable risk of incurring specific levels of 

damage, and the consequential losses that occur as a result of this damage, at 

a specified level of seismic hazard. 

Losses can be associated with structural damage, nonstructural damage, or 

both. They can be expressed in the form of casualties, direct economic costs, 

and downtime (time out of service), resulting from damage. Methods for 

estimating losses and communicating these losses to stakeholders are at the 

heart of the evolution of performance-based design, and are discussed in 

more detail later in this Program Plan. 
4 1: Introduction FEMA 445 

Figure 1-1 Performance-based design flow diagram 

Generally, a team of decision makers, including the building owner, design 

professionals, and building officials, will participate in the selection of 

performance objectives for a building. This team may consider the needs and 

desires of a wider group of stakeholders including prospective tenants, 

lenders, insurers and others who have impact on the value or use of a 

building, but may not directly participate in the design process. 

Stakeholders must evaluate the risk of a hazard event occurring, and must 

obtain consensus on the acceptable level of performance. The basic questions 

that should be asked are: 

• What events are anticipated? 

• What level of loss/damage/casualties is acceptable? 

• How often might this happen? 

While specific performance objectives can vary for each project, the notion 

of acceptable performance follows a trend generally corresponding to: 

• Little or no damage for small, frequently occurring events 

• Moderate damage for medium-size, less frequent events 
FEMA 445 1: Introduction 5 

• Significant damage for very large, very rare events 

Once the performance objectives are set, a series of simulations (analyses of 

building response to loading) are performed to estimate the probable 

performance of the building under various design scenario events. In the 

case of extreme loading, as would be imparted by a severe earthquake, 

simulations may be performed using nonlinear analysis techniques. 

If the simulated performance meets or exceeds the performance objectives, 

the design is complete. If not, the design is revised in an iterative process 

until the performance objectives are met. In some cases it may not be 

possible to meet the stated objective at reasonable cost, in which case, some 

relaxation of the original objectives may be appropriate. 

1.4 Advantages of Performance-Based Seismic Design 

In contrast to prescriptive design approaches, performance-based design 

provides a systematic methodology for assessing the performance capability 

of a building, system or component. It can be used to verify the equivalent 

performance of alternatives, deliver standard performance at a reduced cost, 

or confirm higher performance needed for critical facilities. 

It also establishes a vocabulary that facilitates meaningful discussion 

between stakeholders and design professionals on the development and 

selection of design options. It provides a framework for determining what 

level of safety and what level of property protection, at what cost, are 

acceptable to stakeholders based upon the specific needs of a project. 

Performance-based seismic design can be used to: 

• Design individual buildings with a higher level of confidence that the 

performance intended by present building codes will be achieved. 

• Design individual buildings that are capable of meeting the performance 

intended by present building codes, but with lower construction costs. 

• Design individual buildings to achieve higher performance (and lower 

potential losses) than intended by present building codes. 

• Design individual buildings that fall outside of code-prescribed limits 

with regard to configuration, materials, and systems to meet the 

performance intended by present building codes. 

• Assess the potential seismic performance of existing structures and 

estimate potential losses in the event of a seismic event. 

• Assess the potential performance of current prescriptive code 

requirements for new buildings, and serve as the basis for improvements 
6 1: Introduction FEMA 445 

to code-based seismic design criteria so that future buildings can perform 

more consistently and reliably. 

Performance-based seismic design offers society the potential to be both 

more efficient and effective in the investment of financial resources to avoid 

future earthquake losses. Further, the technology used to implement 

performance-based seismic design is transferable, and can be adapted for use 

in performance-based design for other extreme hazards including fire, wind, 

flood, snow, blast, and terrorist attack. 

1.5 First-Generation Performance-Based Procedures 

Performance-based design as a formal process originated in response to the 

seismic design problem in the 1990’s, in which code-based strength and 

ductility requirements applicable for the design of new buildings could not be 

practically or reliably applied to the evaluation and upgrade of existing 

buildings. 

Preparation of the initial set of procedures for performance-based seismic 

design commenced in 1992, as the capstone project in the FEMA program to 

reduce the seismic hazards of existing buildings. That initial effort 

culminated with the publication of the FEMA 273 Report, NEHRP 

Guidelines for the Seismic Rehabilitation of Buildings (ATC, 1997a), and its 

companion document the FEMA 274 NEHRP Commentary on the 

Guidelines for the Seismic Rehabilitation of Buildings (ATC, 1997b), which 

addressed seismic upgrade of existing buildings. Concurrently, the Structural 

Engineers Association of California developed the Vision 2000 Report, 

Performance-Based Seismic Engineering of Buildings (SEAOC, 1995), 

which described a performance-based seismic design framework for design 

of new buildings. These documents outlined the initial concepts of 

performance levels related to damageability, and varying levels of hazard. 

These first-generation procedures introduced the concept of performance in 

terms of discretely defined performance levels with names intended to 

connote the expected level of damage: Collapse, Collapse Prevention, Life 

Safety, Immediate Occupancy, and Operational Performance. They also 

introduced the concept of performance related to damage of both structural 

and nonstructural components. Performance Objectives were developed by 

linking one of these performance levels to a specific level of earthquake 

hazard. 

First-generation procedures also introduced a set of analytical procedures of 

varying levels of complexity that could be used to simulate the seismic 

response of buildings, and provided a comprehensive set of guidelines on 
FEMA 445 1: Introduction 7 

nonlinear analysis techniques and acceptance criteria. These first-generation 

procedures represented an important improvement over then-current building 

code procedures in that they provided a systematic means of designing 

buildings to achieve a desired level of performance. 

1.6 Present Second-Generation Performance-Based 

Procedures 

At present, performance-based seismic design practice is generally based on 

implementation of procedures and criteria contained within the FEMA 356 

Prestandard and Commentary for the Seismic Rehabilitation of Buildings 

(ASCE, 2000). FEMA 356 represents an incremental improvement to the 

first-generation procedures of FEMA 273. The development of FEMA 356 

included technical updates to the analytical requirements and acceptance 

criteria of FEMA 273 based on information gained from the use of the 

procedures in engineering practice, and from the FEMA 343 Report, Case 

Studies: An Assessment of the NEHRP Guidelines for Seismic Rehabilitation 

of Buildings (BSSC, 1999). 

With the development of second-generation performance-based procedures, 

engineering practitioners have become more familiar with its concepts. 

Performance-based seismic design has become a staple in engineering 

practice, and the use of advanced nonlinear analysis techniques is becoming 

more commonplace. Although intended for existing buildings, the 

procedures are being extrapolated for use in the performance-based design of 

new buildings. 

The expanded use of performance-based procedures in the present secondgeneration has resulted in a knowledge base of practical experience on 

designing with performance-based criteria and communicating with 

stakeholders on performance-based design issues. 

1.7 The Need for Next-Generation Performance-Based 

Procedures 

As the state of knowledge and experience base advances, limitations in 

second-generation procedures are being identified by researchers and 

practitioners. These limitations include: (1) questions regarding the accuracy 

of second-generation analytical procedures in predicting actual building 

response; (2) questions regarding the level of conservatism present in 

second-generation acceptance criteria; (3) the inability to reliably and 

economically apply second-generation performance-based procedures to the 

design of new buildings; and (4) the need for alternative ways of 
8 1: Introduction FEMA 445 

communicating performance to stakeholders that is more meaningful and 

useful for decision-making purposes. 

In order to fulfill the promise of performance-based engineering and help 

ensure that performance-based seismic design delivers on its full potential for 

reducing future losses from earthquakes, next-generation performance-based 

design procedures are needed to: 

• Revise the discrete performance levels defined in first-generation 

procedures to create new performance measures (e.g. repair costs, 

casualties, and time of occupancy interruption) that better relate to the 

decision-making needs of stakeholders, and that communicate these 

losses in a way that is more meaningful to stakeholders; 

• Create procedures for estimating probable repair costs, casualties, and 

time of occupancy interruption, for both new and existing buildings;

• Expand current nonstructural procedures to explicitly assess the 

damageability and post-earthquake functionality of nonstructural 

components and systems, which can constitute a significant percentage 

of the economic loss associated with damaging earthquakes; 

• Develop a framework for performance assessment that properly accounts 

for, and adequately communicates to stakeholders, limitations in our 

ability to accurately predict response, and uncertainty in the level of 

earthquake hazard; 

• Refine current analytical techniques to improve our ability to more 

accurately simulate building response; 

• Fill knowledge gaps and investigate the conservatism and reliability of 

present second-generation acceptance criteria; and 

• Modify current structural procedures to assess performance based more 

on global response parameters, so that the response of individual 

components does not unnecessarily control the prediction of overall 

structural performance. 

1.8 Framework for Next-Generation Performance-Based 

Procedures and Relationship to HAZUS 

Next-generation performance-based design procedures will be developed 

using an analytical framework for estimating risk that is well developed and 

has precedent in a variety of proprietary risk analysis software packages 

commonly used by the insurance industry and others. The framework will be 

used to estimate the possibility of incurring earthquake-induced direct losses 

(repair costs), casualties, and downtime (time of occupancy interruption) for 
FEMA 445 1: Introduction 9 

individual buildings of interest, and will address both new buildings and 

existing buildings. The technical details of the framework for nextgeneration building-specific loss estimation procedures are described in 

Appendix A. 

Under contract with the FEMA, the National Institute of Building Sciences 

has implemented a form of this methodology in the Hazards U.S. (HAZUS) 

loss estimation software. HAZUS was developed primarily for providing 

policy makers and local planners with the ability to project the potential 

impacts of earthquakes, hurricanes, and floods on large portfolios of 

buildings. 

HAZUS includes a methodology for developing a performance estimate on a 

specific building. Known as the HAZUS Advanced Engineering Building 

Module (AEBM), it enables an experienced engineer with considerable 

expertise to develop building-specific relationships between earthquake 

intensity, damage, and loss. These relationships, however, depend on firstand second-generation performance-based analytical techniques for which 

limitations have been identified and improvement is needed. Also, the 

method of characterizing the performance of nonstructural components in 

HAZUS AEBM is very general, and cannot readily account for the various 

installation details of such components inherent in an individual building 

design. Therefore, it cannot be used to assist designers in evaluating the 

potential benefits of design decisions related to improving nonstructural 

performance. 

Together these factors limit the usefulness of HAZUS platform in taking 

advantage of the benefits of performance-based design. As a result, HAZUS 

is most applicable to performing global estimates of loss on the general 

building stock in a region, and is not directly applicable to the performancebased evaluation or design of individual buildings. To the extent that 

information contained within HAZUS platform can be used for performing 

individual building assessments, that information will be incorporated within 

the framework of next-generation performance-based procedures developed 

under this Program Plan. 

FEMA 445 2: Program Plan 11 

Chapter 2 

Program Plan: Goals, 

Background, Organization, 

and the Performance-Based 

Design Process 

2.1 Program Goals 

This Program Plan serves as the basis for a two-phase, multiyear project that 

will result in next-generation performance-based seismic design guidelines 

that: 

• Are practical, efficient, effective, and applicable to both the upgrade of 

existing buildings and the design of new buildings; 

• Define and use building performance goals that are both measurable and 

meaningful to building owners and other decision-makers when selecting 

a basis for design; 

• Quantify uncertainty regarding the ability of a building to achieve the 

desired performance goals; 

• Are suitable for practical implementation in a design office; and 

• Can be used to improve the provisions of present-day building codes and 

design procedures. 

2.2 Program Background 

In September 2001, FEMA contracted with the Applied Technology Council 

to begin implementation of a plan to develop next-generation performancebased seismic design procedures and guidelines. The preparation of this 

Program Plan, and developmental work completed to date, has been 

performed under the ATC-58 project, Development of Next-Generation 

Performance-Based Seismic Design Guidelines for New and Existing 

Buildings. Work to be performed under this Program Plan updates, refines, 

and extends the performance based seismic design work of several earlier 

projects including: 

• FEMA 273/274, NEHRP Guidelines and Commentary for the Seismic 

Rehabilitation of Buildings (ATC, 1997a, b). 
12 2: Program Plan FEMA 445 

• FEMA 356, Prestandard and Commentary for the Seismic Rehabilitation 

of Buildings (ASCE, 2000), which brought FEMA 273/274 to the 

prestandard level. The FEMA 356 document is in the process of being 

replaced by the ASCE 41 Standard for Seismic Rehabilitation of Existing 

Buildings (ASCE, 2006). 

• ATC-40, Seismic Evaluation and Retrofit of Concrete Buildings (ATC, 

1996). 

• Vision 2000, Performance-Based Seismic Engineering of Buildings

(SEAOC, 1995). 

This Program Plan updates two earlier FEMA action plans for developing 

next-generation of performance based seismic design procedures: FEMA 283 

Performance-Based Seismic Design of Buildings – an Action Plan (EERC, 

1996), and FEMA 349 Action Plan for Performance Based Seismic Design

(EERI, 2000). Both of these earlier plans called for multi-year development 

programs that would advance the technical aspects of performance-based 

design, and also address the needs of various stakeholder groups such as 

building owners, commercial and residential tenants, regulators, lenders, and 

insurers. 

This Program Plan is also intended to implement the developing body of 

related earthquake engineering research as outlined in Securing Society 

Against Catastrophic Earthquake Losses (EERI, 2002), a national research 

plan developed by the Earthquake Engineering Research Institute on behalf 

of the National Science Foundation. 

2.3 Preparatory Work from 2001 to Date 

Initial work as part of the development of this Program Plan included an 

evaluation of alternative means of characterizing performance as a basis for 

design, and a review and update of FEMA 349. The following elements of 

the FEMA 349 Action Plan have already been conducted in the development 

of this Program Plan, and have served to help formulate the management 

structure and technical framework for the development of next-general 

performance-based seismic design guidelines: 

• A project management structure was established in early 2002, including 

a Project Management Committee to direct the project technical 

activities, and a Project Steering Committee to provide project oversight 

and linkage with the research and stakeholder communities. The roles 

and responsibilities of these committees are described in Section 3.3.
FEMA 445 2: Program Plan 13 

• A Workshop on Communicating Earthquake Risk was held in June 2002 

and was attended by representatives of several important stakeholder 

communities including building regulators, mortgage lenders, property 

insurance professionals, property managers, developers and corporate 

risk managers, as well as members of the project team. The purpose of 

the workshop was to confirm that performance-based design would be 

accepted by the stakeholder communities, identify aspects of earthquake 

performance of buildings that are of most concern to stakeholders, and 

determine how best to express building performance in terms that are 

understandable and useful to stakeholders and decision-makers. The 

workshop program, activities, findings, and a list of workshop 

participants have been documented in the ATC-58-1 Report, 

Proceedings of FEMA-Sponsored Workshop on Communicating 

Earthquake Risk, which can be downloaded from the ATC web site 

(www.atcouncil.org). 

• As part of the effort to make the next-general performance-based seismic 

design guidelines more understandable and more useful to stakeholders 

and decision-makers, a Task Group was formed in May 2002 to evaluate 

alternative methods of expressing and communicating building 

performance and to develop a report recommending how the project 

should characterize performance. That Task Group participated in the 

June 2002 workshop, and subsequently developed the ATC-58-2 Report 

Preliminary Evaluation of Methods for Defining Performance, which can 

be downloaded from the ATC web site (www.atcouncil.org). In addition 

to summarizing current stakeholder preferences for communicating 

earthquake risk, this report documents the ways in which performance 

has been characterized in the past.

• A Performance-Based Design Workshop was held in February 2003 and 

was attended by prominent members of the structural and earthquake 

engineering research and practice communities as well as members of the 

project team. The purpose of this workshop was to obtain information 

on important advances in performance-based design and input on 

modifications that should be made to the FEMA 349 Action Plan. The 

workshop program, presentations, discussions, an initial draft of 

recommended updates to the original FEMA 349 Action Plan, and a list 

of workshop participants have been documented in the ATC-58-3 

Report, Proceedings of FEMA-Sponsored Workshop on PerformanceBased Seismic Design, which can be downloaded from the ATC web site 

(www.atcouncil.org). 
14 2: Program Plan FEMA 445 

• A Structural Performance Products (SPP) Team, a Nonstructural 

Performance Products Team (NPP), and a Risk Management Products 

(RMP) Team were established in September 2002. These three teams 

were charged with reviewing FEMA 349, reviewing input received from 

the workshops, and updating FEMA 349 to serve as the basis for this 

Program Plan. The roles and responsibilities of these teams are described 

in Chapters 3 through 6. 

As described above, key activities conducted to date by the project have 

focused on identifying and developing a system that will allow effective 

communication of earthquake performance choices in ways that are 

meaningful to stakeholders and decision-makers. No one way of expressing 

building performance would meet the needs and capabilities of all decisionmakers, in part because stakeholders have diverse needs and varying levels 

of knowledge and experience. However, all decision-makers must 

understand the risk associated with various options in order to make an 

intelligent decision. To embrace diverse needs, the Project Management 

Committee developed a sophisticated and flexible framework for estimating 

probable earthquake losses in buildings, for either a single scenario event or 

on a probabilistic basis. 

Stakeholders and decision-makers will continue to be involved in the project 

as work progresses. These activities include ongoing review and input by 

stakeholder representatives on the Project Steering Committee, periodic input 

to and reviews by stakeholders on various project products, and a series of 

efforts that focus on stakeholder needs: 

• An effort to identify the key decision-making parameters and processes 

used by different stakeholder groups. 

• Efforts to develop simple tools to assist decision-makers in selecting 

appropriate performance objectives; and 

• Development of guidelines to assist stakeholders in taking advantage of 

the benefits of performance-based design, including considerations of 

maintenance. 

 2.4 Program Organization 

This Program Plan is divided into two phases: 

• Phase 1: Developing a Methodology for Assessing the Seismic 

Performance of Buildings. In Phase 1, a methodology will be developed 

for assessing the probable seismic performance of individual buildings in 

future earthquakes. 
FEMA 445 2: Program Plan 15 

• Phase 2: Developing Performance-Based Seismic Design Procedures 

and Guidelines. In Phase 2, seismic design procedures and guidelines 

will be developed to assist engineers in designing buildings to meet 

desired performance goals, and to assist stakeholders in taking advantage 

of the benefits of performance-based design. 

Work in each phase will be conducted in six broad categories envisaged in 

the FEMA 349 Action Plan: 

• Planning and Management Program; 

• Structural Performance Products; 

• Nonstructural Performance Products; 

• Risk Management Products; 

• Guidelines Products; and 

• Stakeholders Guide Products. 

The tasks associated with these categories of work are described in Chapters 

3 through 6, and summarized briefly below: 

Planning and Management Program. The purpose of the Planning and 

Management Program tasks are to ensure that the project achieves the vision 

of the plan, and results in products that are accessible and relevant to 

stakeholders. They include establishing a project management structure, 

oversight committees, and a formal program to educate stakeholders about 

performance-based seismic design. 

Structural Performance Products. The purpose of the Structural 

Performance Products tasks are to develop practical and reliable 

methodologies for assessing the seismic performance of structural systems 

found in both new and existing buildings, at various seismic hazard levels. 

These assessment methodologies are intended for use by engineers in 

designing structures capable of achieving selected performance goals. 

Recent research results will be incorporated to improve analysis and design 

procedures and reduce uncertainties in assessing performance. 

Nonstructural Performance Products. The Nonstructural Performance 

Products tasks are similar to the Structural Performance Products tasks, but 

focus on the nonstructural components of new or existing buildings. 

Nonstructural components include partitions, ceilings, piping, equipment, 

contents, and other components and systems attached to the structural 

framing system. The Nonstructural Performance Products efforts will 

address both the installation of new components and the protection of 
16 2: Program Plan FEMA 445 

components already in place in existing buildings. It will also develop 

guidelines for component testing and certification. 

Risk Management Products. The Risk Management Products tasks are 

intended to be oriented primarily around financial issues, but also address 

casualty issues. They include development of methodologies for calculating 

the costs and benefits of implementing various options under performancebased design. A major effort under this set of tasks includes the development 

of methods to combine various levels of risk, performance, and hazard to 

allow a wide range of design objectives to be evaluated as a basis for nextgeneration procedures. Activities include studies on reliability, cost-benefit 

modeling, loss reduction, capital planning, and other factors related to risk 

management. A focus is to provide guidance to stakeholders in selecting 

appropriate performance objectives. 

Guidelines Products. Guidelines Products are the guidelines documents 

that will be used by engineers and other design professionals in 

implementing next-generation performance-based seismic design procedures 

in practice. It is intended that these documents would be published as FEMA 

guidelines that could be incorporated into future code procedures, if 

appropriate. These guidelines are envisaged to form the technical basis for 

everyday design practice, and bring consistency to performance-based 

seismic design throughout the industry. The guidelines will be usable for 

both design of new buildings and upgrade of existing buildings, and will 

include explanatory material (technical commentary, appendices, or 

supporting documents) to assist in their use. The preparation of Guidelines 

Products will be performed as part of the Structural Performance Products, 

Nonstructural Performance Products, and Risk Management Products tasks. 

Stakeholders Guide Products. Stakeholders Guide Products are envisaged 

to function as references and planning tools for owners, institutions with 

financial interests in the building under consideration, and other nontechnical decision-makers. Stakeholders Guide Products will include 

instruction on the selection of appropriate performance objectives, and 

financial tools that permit decision-makers to make funding and investment 

decisions using performance-based design concepts. These guides are to be 

written for non-technical audiences and will contain graphical aids and 

example applications. The preparation of Stakeholders Guide Products will 

be performed as part of the Structural Performance Products, Nonstructural 

Performance Products, and Risk Management Products tasks. 
FEMA 445 2: Program Plan 17 

2.5 Performance-Based Seismic Design Process 

This section provides an expanded discussion of the performance-based 

seismic design process introduced in Section 1.3, as it relates to nextgeneration performance-based design procedures envisioned by this Program 

Plan. 

As described earlier, performance-based design is an iterative process that 

begins with the selection of performance objectives, followed by the 

development of a preliminary design, an assessment as to whether or not the 

design meets the performance objectives, and finally redesign and 

reassessment, if required, until the desired performance level is achieved. 

Each of these steps is described in the sections that follow. Figure 2-1 shows 

how Phases 1 and 2 of this Program Plan will contribute to the steps in the 

overall process. A more detailed description of the technical framework for 

the next-generation seismic performance assessment methodology is 

provided in Appendix A. 

Figure 2-1 Performance-based design process as it relates to Phase 1 and Phase 2 of the Program Plan. 

2.5.1 Step 1: Select Performance Objectives 

The process begins with the selection of design criteria stated in the form of 

one or more performance objectives. Performance objectives are statements 

of the acceptable risk of incurring different levels of damage and the 

consequential losses that occur as a result of this damage, at a specified level 
18 2: Program Plan FEMA 445 

of seismic hazard. Since losses can be associated with structural damage, 

nonstructural damage, or both, performance objectives must be expressed 

considering the potential performance of both structural and nonstructural 

systems. 

In the next-generation performance-based design procedures, performance 

objectives are statements of the acceptable risk of incurring casualties, direct 

economic loss (repair costs), and occupancy interruption time (downtime) 

associated with repair or replacement of damaged structural and 

nonstructural building elements, at a specified level of seismic hazard. These 

performance objectives can be stated in three different risk formats: 

An intensity-based performance objective is a quantification of the 

acceptable level of loss, given that a specific intensity of ground shaking is 

experienced. An example of an intensity-based performance objective is a 

statement that if ground shaking with a 475-year-mean-recurrence intensity 

occurs, repair cost should not exceed 20 percent of the building’s 

replacement value, there should be no life loss or significant injury, and 

occupancy interruption should not exceed 30 days. 

A scenario-based performance objective is a quantification of the acceptable 

level of loss, given that a specific earthquake event occurs. An example of a 

scenario-based performance objective is a statement that if a magnitude-7.0 

earthquake occurs on the San Andreas fault, repair costs should not exceed 

5% of the building replacement cost, there should be no life loss or 

significant injury, and occupancy of the building should not be interrupted 

for more than a week. 

A time-based performance objective is a quantification of the acceptable 

probability over a period of time that a given level of loss will be 

experienced or exceeded, considering all of the earthquakes that might affect 

the building in that time period and the probability of occurrence of each. 

An example of a time-based performance objective is a statement that there 

should be less than a 2 percent chance in 50 years that life loss will occur in 

the building due to earthquake damage, on the average the annual earthquake 

damage repair costs for the building should not exceed 1% of the 

replacement cost, and the mean return period for occupancy interruption 

exceeding one day should be 100 years. 

Phase 2 of this Program Plan includes the development of guides to assist 

stakeholders in selecting appropriate performance objectives, and taking 

advantage of the benefits of performance-based design. 
FEMA 445 2: Program Plan 19 

2.5.2 Step 2: Develop Preliminary Building Design 

The preliminary design for a structure includes definition of a number of 

important building attributes that can significantly affect the performance 

capability of the building. These attributes include: 

• Location and nature of the site. 

• Building configuration, including the number of stories, story height, 

floor plate arrangement at each story, and the presence of irregularities. 

• Basic structural system, for example, steel moment frame or masonry 

bearing walls. 

• Presence of any protective technologies, for example, seismic isolators, 

energy dissipation devices, or damage-resistant elements. 

• Approximate size and location of various structural and nonstructural 

components and systems, and specification of the manner in which they 

are installed. 

Selection of an appropriate preliminary design concept is important for 

effectively and efficiently implementing the performance-based design 

process. Inappropriate preliminary designs could result in extensive iteration 

before an acceptable solution is found, or could result in solutions that do not 

efficiently meet the performance objectives. 

At present, engineers have few resources on which to base a preliminary 

design for meeting a specified performance objective. Some may refer to 

current building code provisions, others might refer to first-generation 

performance-based design procedures, and still others might use a more 

intuitive approach. 

Phase 2 of this Program Plan includes the development of guides to assist 

engineers in identifying appropriate strategies for design and developing 

efficient preliminary designs. 

2.5.3 Step 3: Assess Performance 

After the preliminary design has been developed, a series of simulations 

(analyses of building response to loading) are performed to assess the 

probable performance of the building. Performance assessment includes the 

following steps: 

• Characterization of the ground shaking hazard. 

• Analysis of the structure to determine its probable response and the 

intensity of shaking transmitted to supported nonstructural components 
20 2: Program Plan FEMA 445 

as a function of ground shaking intensity. In the case of extreme loading, 

as would be imparted by a severe earthquake, simulations may be 

performed using nonlinear analysis techniques. 

• Determination of the probable damage to the structure at various levels 

of response. 

• Determination of the probable damage to nonstructural components as a 

function of structural and nonstructural response. 

• Determination of the potential for casualty, capital and occupancy losses 

as a function of structural and nonstructural damage. 

• Computation of the expected future losses as a function of intensity, 

structural and nonstructural response, and related damage. 

Performance assessment is based on assumptions of a number of highly 

uncertain factors. These factors include: 

• Quality of building construction and building condition at the time of the 

earthquake. 

• Actual strength of the various materials, members, and their connections 

incorporated in the building. 

• Nature of building occupancy at the time of the earthquake, the types of 

tenant improvements that will be present, how sensitive these tenant 

improvements might be to the effects of ground shaking, and the 

tolerance of the occupancy to operating in less than ideal conditions. 

• Availability of designers and contractors to conduct repairs following the 

earthquake. 

• Owner’s efficiency in obtaining the necessary assistance to assess and 

repair damage. 

To complete a performance assessment, statistical relationships between 

earthquake hazard, building response, damage, and then loss are required. In 

a general sense, the process involves the formation of four types of 

probability functions, respectively termed: hazard functions, response 

functions, damage functions, and loss functions, and mathematically 

manipulating these functions to assess probable losses. 

Hazard functions are mathematical expressions of the probability that a 

building will experience ground shaking of different intensity levels, where 

intensity may be expressed in terms of peak ground acceleration, spectral 

response acceleration or similar parameters. Hazard functions can be derived 

from the U.S. Geological Survey (USGS) ground shaking hazard maps, or 
FEMA 445 2: Program Plan 21 

may be developed based on a site-specific study that considers the seismicity 

of various faults in the region and the response characteristics of the building 

site. 

Response functions are mathematical expressions of the conditional 

probability of incurring various levels of building response, given that 

different levels of ground shaking intensity are experienced. Building 

response is expressed in the form of parameters that are obtained from 

structural analysis, including story drifts, member forces, joint plastic 

rotation demands, floor accelerations and similar parameters. They are 

obtained by performing structural analysis of a building for different 

intensities of ground shaking. 

Damage functions are mathematical expressions of the conditional 

probability that the building as a whole, or individual structural and 

nonstructural components, will be damaged to different levels, given that 

different levels of building response occur. Damage functions are generally 

established by laboratory testing, analytical simulation or a combination of 

these approaches. 

Loss functions are mathematical expressions of the conditional probability 

of incurring various losses, including casualties, repair and replacement 

costs, and occupancy interruption times, given that certain damage occurs. 

They are determined by postulating that different levels of building damage 

have occurred and estimating the potential for injury persons who may be 

present as well as the probable repair /restoration effort involved. 

The mathematical manipulation of these functions may take on several 

different forms. For some types of performance assessments, closed-form 

solutions can be developed that will enable direct calculation of loss. For 

other types of assessment, it may be necessary to perform either numerical 

integration or Monte Carlo type analyses. Appendices B and C provide more 

detailed technical information on these alternative computations of loss. 

2.5.4 Step 4: Revise Design 

If the simulated performance meets or exceeds the performance objectives, 

the design is completed. If not, the design must be revised in an iterative 

process until the performance objectives are met. 

The design guides, to be developed in Phase 2 of this Program Plan, for 

assisting engineers in identifying appropriate strategies for design and for 

developing efficient preliminary designs are intended to serve as resources 

for efficient redesign to meet performance objectives. In some instances it 
22 2: Program Plan FEMA 445 

may not be possible to meet the stated objectives at reasonable cost, in which 

case, some relaxation of the original performance objectives may be 

appropriate. 

2.6 Applicability of Performance-Based Design to Other 

Structural Hazards 

Design professional and stakeholder communities are also interested in the 

development of performance-based design procedures and guidelines for 

other extreme hazards including fire, wind, flood, snow, blast, and 

progressive collapse due to blast or explosion. 

There is substantial past precedent to indicate that practice improvements in 

performance-based design for seismic resistance have direct impact and 

applicability to performance-based design for other hazards. For example, 

the performance-based design options contained both in the International 

Performance Code (ICC, 2001) and NFPA-5000 Building and Construction 

Safety Code (NFPA, 2003), which are applicable to the full range of design 

perils, are patterned after the performance basis developed for FEMA 356 

(ASCE, 2000). The GSA Progressive Collapse Guidelines (ARA, 2003) 

used in the design of federal buildings to resist terror-related blast hazards 

are also based on technology contained in the FEMA 356 Prestandard as 

well as the FEMA 350 Recommended Seismic Design Criteria for New Steel 

Moment-Frame Buildings (SAC, 2000a), a publication on performance-based 

seismic design of steel moment frame structures. 

The basic methodology developed under this program does not presently 

address design for other hazards directly; however, the technological 

framework and procedures are transferable, and with modification, could be 

applicable to performance-based design for other hazards. While this 

Program Plan does not explicitly include development of design guidance for 

other hazards, measures will be taken to ensure coordination of the 

development of performance-based seismic design guidelines with other 

parallel efforts. Relevant material for other hazards will be referenced or 

incorporated into project publications, where applicable. These activities 

will be carried out on an ongoing basis by the Project Management 

Committee, the Project Steering Committee, and other members of the 

project team.
FEMA 445 3: Phase 1: Developing a Methodology 23 

Chapter 3 

Phase 1: Developing a 

Methodology for Assessing the 

Seismic Performance of Buildings

3.1 Phase 1 Objectives 

Phase 1 of this Program Plan, Developing a Methodology for Assessing the 

Seismic Performance of Buildings, will develop a methodology for assessing 

the probable performance of individual buildings in future earthquakes. 

Work preparatory to beginning Phase 1 has already been performed, and the 

Program Plan can be initiated immediately. 

Phase 1 will update and refine the existing framework for performance 

assessment available in present-generation performance-based procedures, 

create a practical methodology to assess the consequences of performance 

(losses) considering the unique design and construction characteristics of 

individual buildings, and establish new vocabulary for communicating 

performance to stakeholders in the form of losses related to casualties, direct 

economic loss (repair costs), and occupancy interruption time (downtime). 

3.1.1 Expandable Framework 

The performance assessment methodology developed in Phase 1 will be 

applicable to all classes of buildings and structural and nonstructural systems 

commonly used in buildings. Research data does not currently exist, 

however, to fill in all the necessary data to complete damage and loss 

calculations for all such structural and nonstructural systems. The 

framework for performance assessment depicted in the guidelines developed 

in Phase 1 will clearly identify where such data exists and where it does not. 

“Space” will be left in the new framework so that new information can be 

“filled in” by future research efforts on specific types of structural and 

nonstructural systems. Where research data does not exist, this framework 

will provide direction on how new data should be developed. Phase 1 of this 

Program Plan has been developed based on the following information: 

1. Complete framework. A complete framework for implementing 

performance assessment procedures will be developed, including 

procedures for developing response, damage, and loss functions for a 

building of any construction and occupancy. The framework will 

include information for selected structural and nonstructural systems, for 
24 3: Phase 1: Developing a Methodology FEMA 445 

which research data exist. Procedures on how new structural and 

nonstructural performance data should be developed and incorporated 

into the methodology will be provided in the project report Interim 

Protocols For Determining Seismic Performance Characteristics of 

Structural and Nonstructural Components Through Laboratory Testing

(FEMA 461, under development). 

2. Structural Systems. Standard structural response, damage, and loss 

functions will be developed for structural systems for which sufficient 

research data presently exist. These systems are identified in Chapter 4. 

Procedures for modifying these functions to suit specific building 

designs will also be developed, so that the methodology can be 

implemented by engineers. The framework will clearly identify where 

such data exists and where it does not, and will allow for future 

expansion to include new research as it is developed. 

3. Nonstructural Components and Systems. Standard nonstructural 

response, damage, and loss functions will be developed for nonstructural 

systems commonly used in buildings. Sufficient earthquake performance 

data for some classes of nonstructural components and systems has been 

developed in support of seismic qualification efforts by the U.S. Nuclear 

Regulatory Commission, the Department of Energy, and private industry 

sources. Efforts will be made to collect these data and obtain permission 

for their use. Procedures for developing the response, damage, and loss 

functions from such data will be developed and documented. For 

nonstructural components and systems for which no such data presently 

exist, engineering judgment will be used to establish notional response, 

damage, and loss functions so that complete performance assessments 

can be performed. 

3.1.2 Research Needed From Other Programs 

To complete the development of a performance assessment methodology that 

addresses all structural and nonstructural systems commonly used in 

buildings, basic research is needed on simulation techniques, structural and 

nonstructural component testing, and ground motion hazard characterization. 

This Program Plan, however, utilizes basic research that has already been 

performed, and assumes that the necessary basic research will be performed 

by other programs: the Network for Earthquake Engineering Simulation 

(NEES) program currently being conducted under National Science 

Foundation sponsorship; the Advanced National Seismic System (ANSS), 

currently being constructed by the U.S. Geologic Survey; the programs of the 

three NSF-funded national earthquake engineering research centers; and 

other university-based research programs. 
FEMA 445 3: Phase 1: Developing a Methodology 25 

It is reasonable to expect that private industry, including the various 

construction materials trade associations and individual construction product 

manufacturers and suppliers, will also perform some of the research 

necessary to facilitate the use of their products and materials in a 

performance-based design environment. 

3.2 Phase 1 Organization 

Phase 1 of the Program Plan is organized around six broad categories of work 

introduced in Section 2.4: Planning and Management Program; Structural 

Performance Products; Nonstructural Performance Products; Risk Management 

Products; Guidelines Products; and Stakeholders Guide Products. 

Phase 1 work has been subdivided into one overall coordinating and 

management function and three technical areas. Work in each technical area 

will be performed by one of three Product Development Teams, consisting of 

dedicated engineers and researchers with specialized expertise structural 

performance, nonstructural performance, or risk management. 

3.3 Phase 1 Project Management 

Planning and Management Program tasks will be carried out within the 

project management structure shown in Figure 3-1. It is envisaged that this 

management structure will be used throughout implementation of both Phase 

1 and Phase 2 of the program. The project management structure consists of 

three committees: 

• Project Management Committee 

• Project Technical Committee 

• Project Steering Committee 

Collectively, these committees provide management, technical oversight, and 

control of the work performed by the three Product Development Teams. 

They are in place to ensure that results are coordinated between the teams 

and consistent with the overall goals of the Program Plan. 
26 3: Phase 1: Developing a Methodology FEMA 445 

Figure 3-1 Project management structure.

3.3.1 Project Management Committee 

The Project Management Committee will review Program activities on a 

regular basis and will be available for immediate consultation by the funding 

agency and by all three Product Development Teams, as required. The 

Project Management Committee will select consultants and form teams to 

carry out program tasks, including product development and review. These 

consultants will be qualified academic researchers, engineering practitioners, 

and/or other personnel qualified to perform the specific functions needed. 

The Project Management Committee will be responsible for defining the 

scope of work for consultants and project teams, and for ensuring that work 

performed by each consultant or team is timely, accurate, and useful. The 

Project Management Committee will: 

• Develop status report formats for each consultant or team to use on a 

regular basis. 

• Act as liaison with other related concurrent research and development 

projects. 

• Hold regular meetings to discuss progress of the project and resolve any 

conflicts. 

FEMA 

Applied Technology Council 

Project Management Committee 

Project Executive Director (Chair) 

Project Technical Director (Co-Chair) 

4 Members 

Project Technical Committee 

Project Technical Director (Chair) 

Structural Performance Products Team 

ATC Staff 

Technical Support 

Administration 

Project Steering Committee 

Nonstructural Performance Products Team 

Risk Management Products Team 
FEMA 445 3: Phase 1: Developing a Methodology 27 

• Serve as a conduit for transfer of information between consultants and 

teams to ensure that all efforts are complimentary and supplementary. 

The Project Management Committee will consist of six people, including a 

Project Executive Director, who will serve as chair and be responsible for the 

management of the project financial performance; the Project Technical 

Director, who will serve as co-chair and be responsible for technical 

direction of project efforts; and four senior representatives, one from each of 

the following communities: engineering research, structural design, building 

regulation, and social science research. The Project Management Committee 

will meet at approximately 6-8 week intervals throughout the project. 

3.3.2 Project Technical Committee 

The Project Technical Committee will coordinate the efforts of the three 

Product Development Teams. It will be composed of the Project Executive 

Director, Project Technical Director, other selected members of the Project 

Management Committee, and team leaders for each of the three Product 

Development Teams. The committee will be chaired by the Project 

Technical Director. 

The Project Technical Committee will generally meet on a quarterly basis 

throughout the duration of the program. Some of these meetings will involve 

additional representatives of the three Development Teams so that specific 

technical issues may be presented and discussed and technical interfaces 

developed and resolved. 

3.3.3 Project Steering Committee 

The Project Steering Committee will serve as an advisory body to the Project 

Management Committee and will be populated to provide diverse 

perspectives on key technical issues and conduct of the project. The Project 

Steering Committee will make recommendations on products to be 

developed, project personnel, timetables for different tasks, and will provide 

technical and content review of products. 

The Project Steering Committee will be composed of 12 to 14 senior 

representatives of various stakeholder communities, including design 

professionals, researchers, building developers, building regulators, building 

owners, lenders, insurers, and other groups. The exact size and composition 

of this group may change over time, as best suits the needs of the program 

and the technical work that is currently being performed. The Project 

Steering Committee will generally meet one or more times per year. 
28 3: Phase 1: Developing a Methodology FEMA 445 

3.4 Summary of Phase 1 Technical Tasks 

Work in each technical area will be performed by one of three Product 

Development Teams: 

• Structural Performance Products Team. Tasks related to assessing the 

performance of structural systems including development of response, 

damage (fragility), and loss functions for various structural systems. 

• Nonstructural Performance Product Team. Tasks related to assessing 

the performance of nonstructural components and systems including 

development of response, damage (fragility), and loss functions for these 

components and systems. 

• Risk Management Product Team. Tasks related to integrating the 

structural and nonstructural performance functions with the ground 

shaking hazard to obtain estimates of performance in terms of probable 

casualties, probable repair and replacement costs, and probable loss of 

occupancy and use of buildings, as well as development of the means for 

communicating these risks to stakeholders and decision-makers. 

A summary of Phase 1 tasks to be performed by each of these teams is 

provided in the subsections that follow. Detail descriptions of Phase 1 tasks 

are provided in Chapter 4. 

3.4.1 Structural Performance Products Tasks 

Principal Phase 1 tasks to be performed by the Structural Performance 

Products (SPP) Team will include: 

• SPP-1: Prepare structural sections of the Performance Assessment 

Guidelines including guidance on selection of ground motions, 

performing structural analysis, development of response functions and 

damage functions. 

• SPP-2: Identify appropriate structural response quantities (engineering 

demand parameters) for use in predicting damage to the different types of 

structural components and systems. 

• SPP-3: Identify appropriate measures of ground shaking intensity, such 

as spectral response acceleration at the structure’s fundamental period, 

and appropriate methods of selecting and scaling ground motion records 

to represent various shaking intensities. 

• SPP-4: Develop rules for modeling and analyzing structures at various 

intensities of shaking, and considering variability in strength, stiffness 

and damping, to derive structure-specific response functions. 
FEMA 445 3: Phase 1: Developing a Methodology 29 

• SPP-5: Determine appropriate damage states for individual structural 

components, and entire structural systems that are sufficient to permit 

estimation of casualties, repair/replacement costs and downtime. 

• SPP-6: Develop structural designs for a series of case study buildings 

that will be used as a basis for development and testing of the 

performance assessment methodology and which will be used as example 

applications in the guidelines. 

• SPP-7: Develop analytical procedures that can be used to predict the 

demands on nonstructural components and systems as a function of 

ground shaking intensity. 

• SPP-8: Develop general procedures that can be used to construct loss 

functions that relate the probability of experiencing various amounts of 

casualties, repair/replacement costs and downtime, as a function of 

structural damage states, and develop default relationships for typical 

structural systems. 

3.4.2 Nonstructural Performance Products Tasks 

Principal Phase 1 tasks to be performed by the Nonstructural Performance 

Products (NPP) Team will include: 

• NPP-1: Prepare nonstructural sections of the Performance Assessment 

Guidelines including guidance on determining the damageability of 

nonstructural components and systems, determining the behavior of these 

components at varying levels of building response, and predicting the 

consequences of damage to these components with regard to casualties, 

repair costs and downtime. 

• NPP-2: Develop a taxonomy of the typical nonstructural components 

and systems found in buildings, identifying those which are damageable 

and which have significant potential consequences in terms of casualties, 

repair/replacement cost and downtime. 

• NPP-3: Identify meaningful damage descriptors for the various types of 

nonstructural components and systems that are useful for determining the 

potential for incurring earthquake induced losses. 

• NPP-4: Identify appropriate characterizations of the shaking input to 

various types of nonstructural components and systems that best 

correlate with damage to these components and systems. 

• NPP-5: Identify and obtain access to the various proprietary and public 

domain databases of information on the seismic damageability of various 

types of nonstructural components. 
30 3: Phase 1: Developing a Methodology FEMA 445 

• NPP-6: Develop standard procedures to perform laboratory tests of 

nonstructural components as a means of developing damage functions for 

these components. 

• NPP-7: Develop approximate, simplified procedures to estimate 

response parameters for nonstructural components for a given set of 

engineering demand parameters. 

• NPP-8: Develop approximate analytical procedures that can be used to 

predict damage sustained by complex nonstructural systems. 

• NPP-9: Develop general procedures that can be used to construct loss 

functions that relate the probability of experiencing various amounts of 

casualties, repair/replacement costs and downtime, as a function of 

nonstructural damage states for various types of components and 

systems, and develop default relationships for typical components and 

systems. 

• NPP-10: Develop specifications of nonstructural components and 

systems for the series of case study buildings that will be used as a basis 

for development and testing of the performance assessment methodology 

and which will be used as example applications in the guidelines. 

3.4.3 Risk Management Products Tasks 

Principal Phase 1 tasks to be performed by the Risk Management Products 

(RMP) Team will include: 

• RMP-1: Prepare sections of the Performance Assessment Guidelines 

relating to the basic performance assessment methodology, including 

methods for expressing seismic performance of buildings, developing 

loss functions and integrating and aggregating losses to produce various 

types of probable casualty, repair/replacement cost and downtime 

assessments. 

• RMP-2: Develop general procedures for determining structural loss 

functions that relate probable casualties, repair/replacement costs and 

downtime to various types of structural damage. 

• RMP-3: Develop general procedures for determining nonstructural loss 

functions that relate probable casualties, repair/replacement costs and 

downtime to various types of nonstructural damage. 

• RMP-4: Develop a basic mathematical approach for calculating probable 

casualties, repair/replacement costs and downtime, as a function of 

ground shaking hazard, structural and nonstructural response and 

damage. 
FEMA 445 3: Phase 1: Developing a Methodology 31 

• RMP-5: Synthesize the basic mathematical approach for calculating 

probable performance into a systematic procedure that can be applied to 

real buildings in the design office. 

• RMP-6: Develop a practical approach that can be used to sum the effects 

of damage to the collection of individual structural and nonstructural 

components that comprise a building, into a coherent estimate of 

probable loss to the building, considering the interaction and 

dependencies involved. 

• RMP-7: Develop practical procedures to calculate loss as a function of 

the predicted damage to various elements. 

• RMP-8: Work with representatives of various stakeholder groups 

including building developers, owners, investors, tenants, regulators, 

lenders, insurers and design professionals to develop a common means of 

communicating seismic performance of buildings that is useful to the 

process of selecting appropriate or desired building performance as a 

basis for design projects. 

• RMP-9: Develop standard methods of characterizing building 

performance that meet the need of the various stakeholders. 

3.5 Phase 1 Projected Program Costs and Schedule 

Phase 1 of this Program Plan was originally intended to be accomplished in 

five years, contingent on the availability of sufficient levels of funding to 

enable the necessary work to be performed in the planned sequence. Figure 

3-2 presents an overall summary of tasks and schedule for the originally 

planned Phase 1 work. Detailed descriptions of Phase 1 tasks are provided in 

Chapter 4. 

The original Phase 1 total projected project costs were estimated at 

approximately $11 million in 2004 dollars. Estimates of personnel and other 

costs associated with the Phase 1 tasks of this Program Plan have been 

developed using prevailing labor costs common to projects of this type at the 

time this plan was prepared, and do not include escalation due to changes in 

the value of money, labor rates, internal government costs, or inflation. 

Table 3-1 presents an overall picture of the Phase 1 program as originally 

developed, broken down by Product Development Area. Table 3-2 presents 

a detailed breakdown of these original costs by task, and shows how these 

costs were intended to have been distributed throughout the program. 

Table 3-3 and Table 3-4 present an overall picture of the Phase 1 reducedscope program prepared at the request of FEMA. The budget for the reducescope program is approximately 50% of that for the original program, and the 
32 3: Phase 1: Developing a Methodology FEMA 445 

project schedule has been extended to seven years. Table 3-3 presents the 

Phase 1 reduced-scope program broken down by Product Development Area, 

and Table 3-4 presents a detailed breakdown of reduced-scope costs by 

specific tasks. The project is currently working at a reduced funding level, 

and Phase 1 development efforts are in year four of the extended seven year 

schedule. 

Figure 3-2 Summary of tasks and schedule for Phase 1: Developing a Methodology for Assessing the Seismic 

Performance of Buildings. 
FEMA 445 3: Phase 1: Developing a Methodology 33 

Table 3-1 Original Projected Costs by Product Development Area, 

Phase 1: Development of Performance Assessment Guidelines 

Product Development Area/Cost Element Cost ($1,000) 

Structural Performance Products $2,545 

Nonstructural Performance Products 2,450 

Risk Management Products 3,080 

Project Management, Administration, Oversight (Review), and 

Other Costs (Travel, Communications, Supplies and Equipment) 3,375 

Project Total $11,450 

Table 3-2 Original Projected Program Costs by Task and Year ($1,000); Phase 1 

Task Year 1 Year 2 Year 3 Year 4 Year 5 Total 

SPP-1 Structural Input to Performance Assessment Guidelines $110 - $110 - $320 540 

SPP-2 Identify Structural Engineering Demand Parameters (EDPs) 130 130 - - - 260 

SPP-3 Identify Intensity Measures 110 - - 110 - 220 

SPP-4 Prepare Analysis Guidelines - 175 175 - - 350 

SPP-5 Identify Structure Damage Measures - 170 170 150 - 490 

SPP-6 Structural Input to Model Building Studies - 150 - 180 180 510 

SPP-7 Develop Procedures for Input to Nonstructural Evaluation - 75 - - - 75 

SPP-8 Develop Structural Loss Functions - - 50 50 - 100 

SPP Total 350 700 505 490 500 2545 

NPP-1 Nonstructural Input to Performance Assessment Guidelines 100 - 100 - 290 490 

NPP-2 Develop Catalog of Nonstructural Components and Systems 150 - - - - 150 

NPP-3 Identify Nonstructural Performance Measures 150 - - - - 150 

NPP-4 Identify Input EDPs for Nonstructural Components 75 - - - - 75 

NPP-5 Develop Nonstructural Performance Database - 170 170 130 - 470 

NPP-6 Develop Nonstructural Performance Evaluation Protocols - - 185 90 - 275 

NPP-7 Simplify Nonstructural EDPs - 195 195 0 - 390 

NPP-8 Develop Procedures for Computing Nonstructural Damage - - 75 155 - 230 

NPP-9 Develop Nonstructural Loss Functions - - 35 35 - 70 

NPP-10 Nonstructural Input to Model Building Studies - 50 - 50 50 150 

NPP Total 475 415 760 460 340 2450 

RMP-1 Develop Input to Performance Assessment Guidelines 100 - 100 - 290 490 

RMP-2 Develop Structural Loss Functions 85 170 170 85 - 510 

RMP-3 Develop Nonstructural Loss Functions - 170 170 170 - 510 

RMP-4 Develop Model for Aggregating Losses - 55 110 70 60 295 

RMP-5 Formulate Concept Aggregation Procedures 135 - - - - 135 

RMP-6 Procedure for Aggregating Local Effects to Global - 85 110 110 40 345 

RMP-7 Develop Loss Integration Procedures - 35 30 40 30 135 

RMP-8 Identify Stakeholder Needs - 65 100 100 85 350 

RMP-9 Develop Standard Performance Characterizations - 45 100 100 65 310 

RMP Total 320 625 890 675 570 3080 

Project Management, Oversight & Administration 475 475 475 475 475 2375 

Other Direct Costs 200 200 200 200 200 1000 

Annual Totals $1,820 $2,415 $2,830 $2,300 $2,085 $11,450 
34 3: Phase 1: Developing a Methodology FEMA 445 

Table 3-3 Reduced-Scope Projected Costs by Product Development Area, 

Phase 1: Development of Performance Assessment Guidelines 

Product Development Area/Cost Element Cost ($1,000) 

Structural Performance Products $785 

Nonstructural Performance Products 786 

Risk Management Products 965 

Project Management, Administration, Oversight (Review), and 

Other Costs (Travel, Communications, Supplies and Equipment) 2462 

Project Total $4998 

Table 3-4 Reduced-Scope Projected Program Costs by Task and Year ($1,000); Phase 1 

Task Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Total 

SPP-1 Structural Input to Performance Assessment Guidelines $8 - $33 - $42 $42 $33 158 

SPP-2 Identify Structural Engr. Demand Parameters) - 20 20 - - - - 40 

SPP-3 Identify Intensity Measures - 20 10 - - - - 30 

SPP-4 Prepare Analysis Guidelines - 10 30 75 - - - 115 

SPP-5 Identify Structure Damage Measures 70 70 20 - - - - 160 

SPP-6 Structural Input to Model Building Studies 17 33 - 17 33 33 - 133 

SPP-7 Dev. Procedures for Input to Nonstructural Evaluation - - - 50 - - - 50 

SPP-8 Develop Structural Loss Functions - 33 33 33 - - - 99 

SPP Total 95 186 146 175 75 75 33 785 

NPP-1 Nonstr. Input to Performance Assessment Guidelines 8 - 33 - 42 42 33 158 

NPP-2 Develop Catalog of Nonstructural Components 20 - - - - - - 20 

NPP-3 Identify Nonstructural Performance Measures - 65 - - - - - 65 

NPP-4 Identify Input EDPs for Nonstructural Components 15 30 - - - - - 45 

NPP-5 Develop Nonstructural Performance Database - - 50 40 - - - 90 

NPP-6 Dev. Nonstructural Performance Evaluation Protocols 20 - - - - - - 20 

NPP-7 Simplify Nonstructural EDPs 10 10 - - - - - 20 

NPP-8 Develop Procedures for Computing Nonstr. Damage - - 65 45 85 - - 195 

NPP-9 Develop Nonstructural Loss Functions - - 10 10 10 10 - 40 

NPP-10 Nonstructural Input to Model Building Studies 17 33 - 17 33 33 - 133 

NPP Total 90 138 158 112 170 85 33 786 

RMP-1 Develop Input to Performance Assessment Guidelines 8 - 33 - 42 42 33 158 

RMP-2 Develop Structural Loss Functions 5 10 - - - - - 15 

RMP-3 Develop Nonstructural Loss Functions 10 20 55 45 45 40 - 215 

RMP-4 Develop Model for Aggregating Losses - - - 17 33 33 - 83 

RMP-5 Formulate Concept Aggregation Procedures 17 33 - - - - - 50 

RMP-6 Proc. for Aggregating Local Effects to Global - 39 40 40 - - - 119 

RMP-7 Develop Loss Integration Procedures - - 20 75 75 100 - 270 

RMP-8 Identify Stakeholder Needs - 15 20 - - - - 35 

RMP-9 Develop Standard Performance Characterizations - 10 10 - - - - 20 

RMP Total 40 127 178 177 195 215 33 965 

Project Management, Oversight & Administration 255 240 230 230 230 240 120 1545 

Other Direct Costs 120 58 137 157 180 135 130 917 

Annual Totals $600 $749 $849 $851 $850 $750 $349 $4998 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 35 

Chapter 4 

Phase 1: Developing a 

Methodology for Assessing the 

Seismic Performance of 

Buildings—Technical Tasks

4.1 Phase 1 Structural Performance Products Tasks 

The purpose of the Structural Performance Products tasks is to develop a 

practical and reliable generalized methodology for assessing the performance 

of building structural systems, including: identification of appropriate 

intensity measures for use in analysis; identification of preferred approaches 

to employing structural analysis to predict building response as a function of 

intensity; and methods of predicting structural damage as a function of 

building response. The Structural Performance Products tasks will be 

performed in coordination with the Risk Management Product tasks related 

to calculating losses as a function of structural and nonstructural damage, and 

the Nonstructural Performance Products tasks that predict nonstructural 

performance as a function of both ground shaking intensity and structural 

response. Finally, the generalized methodology will be developed into a 

straightforward and practical series of implementation guidelines. The first 

guidelines to be developed will be those for which adequate research results 

are currently available. For the purposes of this Program Plan, four 

representative systems are planned to be used. Systems for which there 

would appear to be adequate research data available and which, in general, 

cover the range of structural systems and behaviors are: 

• Steel moment frames 

• Concrete moment frames 

• Cantilever concrete wall systems 

• Wood wall systems 

Should adequate research data and funding be available, this effort could be 

extended to include other systems, including braced steel frames, coupled 

concrete walls, and various forms of masonry wall systems. 
36 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

The Structural Performance Products Team consisting of a team leader, a 

researcher knowledgeable in the state of art and state of practice of structural 

analysis, and at least one engineer or researcher with extensive expertise and 

knowledge of the behavior and design requirements for each of the structural 

systems will perform these tasks. The team will include at least one expert 

practicing structural engineer routinely engaged in the design, evaluation, 

and upgrade of buildings. The Structural Performance Products Team will 

retain graduate student assistants and consultants to perform many of the 

development tasks. 

Figure 4-1 presents the Structural Performance Products tasks that will be 

undertaken in Phase 1, along with a schedule for their completion (see also 

Table 3-1). These SPP tasks are detailed in the sections below. 

Figure 4-1 Phase 1: Schedule for structural performance products tasks. 

4.1.1 Structural Input to Performance Assessment Guidelines 

(SPP-1) 

The development of performance assessment guidelines will be jointly 

performed by the three Product Development Teams. The Structural 

Performance Products Team will be responsible for developing those 

portions of the guidelines relating to characterizing ground shaking hazards 

through intensity measures, modeling and analyzing structures to derive 

building-specific structural response functions and to develop input data for 

the evaluation of nonstructural components and systems, identification of 

structural damage measures, and development of structural fragilities. 

The performance assessment guidelines will be developed incrementally over 

the five-year span of Phase 1. Preliminary draft guidelines will be developed 

in the first year of the program. This will enable the Structural Performance 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 37 

Products Team to conceptualize the various design tasks that must be 

performed and understand how they fit into the overall process of 

performance-based seismic design. The draft guidelines developed in this 

initial effort will be updated, expanded, and added to throughout Phase 1 to 

incorporate the results of completed tasks in all three program areas. The 

final product of this task will be ready-for-publication sections of guidelines 

on structural performance assessment. 

4.1.2 Identify Structural Engineering Demand Parameters 

(SPP-2) 

Task SPP-2 will identify appropriate engineering demand parameters for use 

in assessing the performance of the four common structural systems (steel 

moment frame, concrete moment frame, wood wall, and concrete and 

masonry wall structures) and their components. 

It is important that the recommended engineering demand parameters can be 

readily obtained from analysis, have relatively small variation at different 

levels of building response, and are meaningful for the purpose of predicting 

the various types of damage of significance to performance assessment for 

the particular structural systems. Engineering demand parameters may 

consist of peak quantities, such as peak interstory drift; cumulative quantities 

such as cumulative strain energy; or combinations of these such as are 

contained in the Park-Ang (1985) and related damage indices. 

A list of the structural components and elements critical to performance for 

each framing system will be identified and engineering demand parameters 

developed. For each of these components and elements, information from 

existing research will be used to identify and characterize the engineering 

demand parameters. Pertinent existing research includes work done under 

the FEMA/SAC1

 Steel Project (for steel moment frames), the FEMA-funded 

CUREE Caltech2

 Wood-Frame Program (for wood walls), and relevant U.S.-

Japan projects. Task SPP-2 will engage faculty and design professionals 

active in these projects in one or more workshops/meetings to assist in 

identifying the appropriate engineering demand parameters. This SPP-2 task 

will be coordinated with efforts undertaken in Task SPP-1 to incorporate 

findings into the performance assessment guidelines, with Task SPP-4 to 

develop analysis guidelines and with Task SPP-5 to develop guidelines for 

translating engineering demand parameters into component damage states. 

 

1

 A joint venture partnership of the Structural Engineers Association of California, 

the Applied Technology Council, and California Universities for Research in 

Earthquake Engineering (CUREE), now known as Consortium of Universities for 

Research in Earthquake Engineering. 

2

 California Institute of Technology 
38 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

A summary report will be prepared describing the engineering demand 

parameters recommended for the performance assessment of components and 

elements of the selected framing systems, and detailed reasons for their 

selection. The report will also address considerations of reliability in 

predicting the engineering demand parameters using various methods of 

analyses (see Task SPP-4) and how well the values of the engineering 

demand parameters can be related to structural and nonstructural damage 

states (Tasks SPP-5 and NPP-7). 

4.1.3 Identify Intensity Measures (SPP-3) 

Task SPP-3 will identify earthquake hazard intensity measures, evaluate 

those that are efficient at predicting engineering demand parameter values, 

and develop recommendations for selection of appropriate ground motion 

representations for use in analysis. Task SPP-3 will document the 

appropriate statistical measures by which correlations between intensity 

measures and engineering demand parameters can be quantified. An internal 

report will be prepared and will recommend specific intensity measures to be 

used for assessing structural and nonstructural performance, characterization 

of ground motion for analysis, and methods of selecting and scaling ground 

motion records to conform to various values of the intensity measures. 

Current practice is to use either peak ground acceleration or spectral 

acceleration at the fundamental period of building vibration as the primary 

intensity measure for performance assessment and design. One purpose of 

this task is to evaluate whether alternative intensity measure definitions are 

warranted and to recommend specific ways of characterizing ground motion, 

as a function of the intensity measures. The primary rational for using 

alternative intensity measures is to reduce the inherent variation in predicted 

values of engineering demand parameters for analyses performed using 

different ground motions scaled to the same intensity measure value. This 

task will provide and document the technical basis for the intensity measures 

recommended for use in building performance assessment. 

Available information will be reviewed to develop a shortlist of alternatives 

that might yield less variation in engineering demand parameter predictions 

for the four structural systems identified above. One or more meetings to 

solicit input from researchers and design professionals knowledgeable on this 

subject will be held, with the ultimate goal of developing two or three 

alternative intensity measures to be considered for possible implementation. 

It is likely that the intensity measures may be distinguished on the basis of 

the performance level, that is, some intensity measures are known to have 

better efficiency in response prediction in either the elastic or inelastic range 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 39 

of behavior, but not both. An internal report will be prepared that documents 

the findings from this task. 

Task SSP-3 will be performed by a project sub-team consisting of a 

geotechnical engineer or engineering seismologist, a structural analysis 

specialist, and a specialist in uncertainty evaluation. The project team will 

operate under the direction of the Structural Performance Products Team 

Leader. Efforts will be made to coordinate with and take advantage of work 

relevant work in this area concurrently being performed by the U. S. 

Geologic Survey and the three NSF earthquake engineering research centers. 

4.1.4 Prepare Analysis Guidelines (SPP-4) 

Task SPP-4 will develop and document one or more structural analysis 

methods for use in structural performance assessment and prediction of 

demands on nonstructural components and elements. This task will include 

consideration of soil-structure interaction and a statistical treatment of the 

uncertainties in earthquake hazards and structural response. These analysis 

methods will be used by design professionals to develop structural response 

functions that predict the values of engineering demand parameters for 

various levels of intensity measures and predict input demands for 

nonstructural components and systems suspended by or within the structure. 

In Task SPP-4, one or more seismic analysis methodologies that will be 

included in the analysis guidelines will be identified. Emphasis will be 

placed on the use of inelastic response-history procedures with a rigorous 

treatment of uncertainties. Other analysis procedures will be examined, but 

will be included in the guidelines only if it is apparent that the procedures are 

sufficiently reliable to permit practical application. More traditional analysis 

procedures, for example nonlinear static analysis, may be found acceptable 

for application to structures within limited ranges of configuration and 

structural period. Linear procedures would be permitted only for: those few 

structures that would be expected to remain elastic, or nearly so, for all 

feasible levels of ground motion intensity; or for single degree-of-freedom 

structures where sufficient statistical data are available to characterize 

inelastic response based on elastic analysis and the uncertainty associated 

with elastic predictions of demands is well-defined. 

Limitations of the selected analysis methods for representing extreme 

nonlinear behavior (e.g., near-collapse) will be documented. Analysis 

guidelines will consider how soil-foundation-structure-interaction (SFSI) 

effects should be considered, when significant, either by explicit modeling of 

soil-foundation elements or appropriate modification of the hazard and/or 

input ground motions, or a combination of these methods. Analysis 
40 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

guidelines will address appropriate statistical modeling of uncertainties in the 

earthquake hazard and structural response. 

The analysis guidelines will be evaluated by application to the case study 

buildings developed under Task SPP-6. Both research-oriented (e.g., 

OpenSees, IDARC, ABAQUS) and commercial (e.g., SAP, ETABS, 

LARSA) software will be used for these studies. Both design professionals 

and researchers (faculty and graduate students) will contribute to the 

analysis/evaluation of the code-compliant buildings developed under Task 

SPP-6. 

The analysis guidelines will address specific issues associated with 

calculating the engineering demand parameters identified in Tasks SPP-2 and 

SPP-7, and with appropriate representation of the earthquake hazard 

consistent with the intensity measures identified in Task SPP-3. Work on 

simpler analysis methods will require studies to calibrate bias and uncertainty 

parameters against inelastic response-history methods, but such work will 

only be undertaken if bias and uncertainty factors are available from other 

sources. 

The results of Task SPP-4 will be incorporated into the analysis sections of 

the Performance Assessment Guidelines (SPP-1). 

4.1.5 Identify Structural Damage Measures (SPP-5) 

Task SPP-5 will develop definitions of appropriate damage measures for the 

four candidate framing systems. The damage measures will be used to form 

functions, relating levels of damage to response, as measured by the 

engineering demand parameters, and also to form loss functions, which relate 

the probable losses in casualties, repair/replacement costs and occupancy 

interruption to damage (see also Appendix A, Seismic Performance 

Assessment). Task SPP-5 will result in a series of chapters on the translation 

of engineering demand parameters into damage measures for the various 

structural systems and their components. Definition of the damage measures 

will be coordinated with the Risk Management Products Team, which will 

develop procedures and models to translate the damage measures into 

appropriate performance (loss) metrics. 

As part of the task of identifying appropriate structural damage measures, it 

will be necessary to decide how performance is to be measured, for example, 

at the component, story, or system level, or a combination of these for 

differing levels of damage, ranging from modest to severe. How the damage 

measures will be integrated will depend to a large extent on how significant 

the damage is. For modest levels of damage, the main consequence of 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 41 

damage will likely be the need for repairs, which probably can be aggregated 

from a component level based on the repair costs and repair time. For more 

severe damage levels, which impair the safety of the occupants, more global 

descriptions of damage will probably be required. 

Procedures for transformation of the quantitative engineering demand 

parameters into the selected damage measures will be developed. This work 

will be coordinated with the Nonstructural Performance Products Team and 

the Risk Management Products Team to include development of a 

generalized procedure to establish measures of building performance using 

values of structural and nonstructural component engineering demand 

parameters. 

4.1.6 Structural Input to Model Building Studies (SPP-6) 

Task SPP-6 will design structural systems for a series of case study buildings 

using current building code provisions. These models will then be subjected 

to the performance assessment procedure. One case study building will be 

developed for each of the four candidate structural systems. The goals of this 

task are threefold: (1) to test-drive the Performance Assessment 

Methodology and tools developed in Tasks SPP-1 through SPP-5 and SPP-7; 

(2) to serve as example applications in the eventual seismic Performance 

Assessment Guidelines, and (3) to provide information on the actual 

expected performance of representative buildings designed to the present 

building code. This task will be performed in coordination with the 

Nonstructural Performance Products Team, who will populate the model 

buildings with nonstructural systems and components, and the Risk 

Management Products Team, who will take the lead in assessing the 

performance of the case study buildings. 

Case study building designs will be prepared for regions of high seismicity, 

such as are found in the western United States. Initial designs will follow the 

requirements of 2003 NEHRP Recommended Provisions for Seismic 

Regulation of Buildings and other Structures (BSSC, 2003). Foundation 

systems and site effects will be included in the designs to the extent that they 

will significantly impact the performance evaluation. 

Once the designs are complete, the Risk Management Products Team will 

direct the use of the developing Performance Assessment Methodology to 

evaluate the performance capability of the designs. Graduate students will be 

involved with this activity. Each of the analysis methods presented in the 

Performance Assessment Guidelines will be used to evaluate the code-based 

designs. These evaluations will likely be repeated several times over the 

course of the project as the assessment methodology is developed and 
42 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

improved, to confirm the workability and completeness of the methodology, 

and to ensure that it can be implemented by design professionals. 

4.1.7 Develop Procedures for Input to Nonstructural Evaluation 

(SPP-7) 

Task SPP-7 will develop procedures for deriving the necessary data for 

evaluation of the performance of nonstructural components and systems from 

analysis of the structural system’s response. These data are termed 

nonstructural engineering demand parameters. Nonstructural engineering 

demand parameters can generally be classified as those that are critical to the 

performance of deformation-sensitive and motion-sensitive components. 

Deformation-sensitive components include glazing, which under certain 

levels of lateral drift will break and fall out of its framing, and partitions, 

which will crack when laterally deformed. A typical engineering demand 

parameter for deformation-sensitive components is interstory drift. 

Nonstructural engineering demand parameters for motion-critical 

components can include floor acceleration, velocity, or displacement spectra 

(or alternative measures of floor motions that correlate with damage to 

nonstructural components). 

Task SPP-7 will be undertaken in coordination with the Nonstructural 

Performance Products Team. The task is scheduled early in the Phase 1 5-

year program, as it is critical to identify appropriate engineering demand 

parameters in order to coordinate activities between the Structural 

Performance Products and Nonstructural Performance Products Teams. 

Identifying nonstructural engineering demand parameters will help guide the 

development of analysis methods in Task SPP-4, the intensity measure 

selection in Task SPP-3, and the benchmark studies in Task SPP-6. Task 

SPP-7 will include one or more meetings to reach consensus between the 

Nonstructural Performance Products and Structural Performance Products 

Teams as to what engineering demand parameters are required from the 

structural analysis to evaluate nonstructural components and building 

contents. Discussions will also address the issue of what nonstructural 

components will influence the structural response, and therefore need to be 

modeled in the structural analysis. 

During Task SPP-7, the analysis methods of Task SPP-4 will be developed 

so that demands (measured in terms of the selected nonstructural engineering 

demand parameters) on nonstructural components can be established as a 

function of intensity measure, as filtered through the structural system. 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 43 

4.1.8 Develop Structural Loss Functions (SPP-8) 

Under Task SPP-8, the Structural Performance Products Team will consult 

with and provide support to the Risk Management Products Team as it 

develops standardized procedures for deriving loss functions for structural 

components and systems as a function of the damage measures. Under Task 

SPP-8, the Structural Performance Products Team will also support the Risk 

Management Products Team in developing standard or default loss functions 

for typical structures comprising the four candidate structural systems. 

4.2 Phase 1 Nonstructural Performance Products Tasks 

The goal of the Nonstructural Performance Products tasks is to develop a 

practical and reliable generalized methodology for assessing the performance 

of nonstructural components and systems in buildings. This will include: 

• Identifying appropriate intensity measures and nonstructural engineering 

demand parameters to characterize the response of these components and 

systems. 

• Identifying preferred approaches to employing structural analysis to 

predict response as a function of intensity and nonstructural engineering 

demand parameters. 

• Methods of predicting damage as a function of response or directly as a 

function of the input intensity measures. 

• Development of procedures for assessing the probable consequences of 

damage to nonstructural components and systems in terms of probable 

casualties, repair/replacement costs, and downtime. 

Work on the Nonstructural Performance Products tasks will be performed in 

parallel and in coordination with the Risk Management Products and 

Structural Performance Products tasks. 

The Nonstructural Performance Products tasks will be conducted by a 

Nonstructural Performance Products Team. The team will be composed of a 

team leader, two researchers with experience in the investigation of the 

performance of nonstructural components, two structural design engineers, a 

practicing architect, a building mechanical engineer, and a building electrical 

engineer. At least one of the researchers will have familiarity with structural 

reliability methods and the development of damage functions. The 

Nonstructural Performance Products Team will also use a number of 

engineering consultants who will perform much of the literature search and 

data gathering efforts. 
44 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

Figure 4-2 presents a schedule for the Nonstructural Performance Products 

tasks in Phase 1. 

Figure 4-2 Phase 1: Schedule for nonstructural performance products tasks. 

4.2.1 Nonstructural Input to Performance Assessment 

Guidelines (NPP-1) 

The development of Performance Assessment Guidelines will be jointly 

performed by the three Product Development Teams. The Nonstructural 

Performance Products Team will be responsible for developing those 

portions of the guidelines that relate to identifying critical nonstructural 

components and systems in a building, determining their importance to the 

building’s performance, characterizing the damagability of the nonstructural 

components and systems, and estimating the demands on these nonstructural 

components and systems as a function of the ground shaking hazard. The 

nonstructural sections of the guidelines will be developed in parallel with, 

and on the same schedule as, structural sections of the guidelines. 

4.2.2 Develop Catalog of Nonstructural Components and 

Systems (NPP-2) 

Task NPP-2 will identify, organize, and catalog the various types of 

nonstructural components, systems, and contents that are vulnerable to 

earthquake-induced loss and that are significant to the overall performance of 

the building. A literature search will be performed to identify past efforts to 

establish such an inventory and this inventory will be extended through the 

efforts of the Nonstructural Performance Products Team. In addition to 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 45 

looking at the importance of individual nonstructural components, Task 

NPP-2 will evaluate how components fit together to form systems (i.e. 

pumps, chillers, and fans are parts of an HVAC3

 system) and characterize the 

effects of damage to a single component on system functionality. The team 

will then identify the nonstructural systems that are typically present in 

various building occupancies, and if sufficient information is available, 

identify the weak links with regard to overall building performance. The 

team will take advantage of work published in Installing Seismic Restraints 

for Mechanical Equipment (VISCMA, 2002), Installing Seismic Restraints 

for Electrical Equipment (VISCMA, 2004a) and Installing Seismic Restraints 

for Piping and Ducts (VISCMA, 2004b). The NPP-2 Task will include 

interviewing owners of different types of facilities to determine the effects of 

potential damage on facility operation and may include walk-downs of 

selected buildings. The team will make judgments as to the significance of 

the various components and systems to overall building performance in order 

to trim the list of components to a manageable number. 

This task will also support the eventual development of performance-based 

seismic design guidelines. As the inventory of nonstructural components and 

systems is developed, the team will identify the detail with which issues of 

design, installation, and maintenance of nonstructural components must be 

evaluated and for which detailed guidelines must be prepared. 

Task NPP-2 will culminate with the development of an internal project report 

on identifying nonstructural components of significance and a scoping report 

on the issues to be evaluated in the overall project. 

4.2.3 Identify Nonstructural Performance Measures (NPP-3) 

Task NPP-3 will identify appropriate measures of nonstructural performance. 

The overall goal in this task is to identify the performance characterizations 

or damage measurements so that the evaluation and design methodologies 

developed in later tasks can be eventually targeted to definitive goals. 

Working with the performance definitions developed in the Structural 

Performance Products tasks, the team will quantify nonstructural 

performance and damage measures of significance (for example, loss of 

functionality, leakage rates, crack widths, tipping, breakage, etc.). This task 

will require a series of meetings with individuals with expertise regarding the 

seismic behavior of different component types. These experts will assist in 

cataloging different modes of behavior of the various component types. The 

deliverable for this task will be an internal project report on recommended 

nonstructural performance characterization and/or damage measures. 

 

3

 Heating, ventilation, air-conditioning 
46 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

4.2.4 Identify Input Engineering Demand Parameters (NPP-4) 

Task NPP-4 will identify the input engineering demand parameters that are 

most appropriate for use in predicting the performance of various 

nonstructural components and systems. These input engineering demand 

parameters may include floor accelerations, interstory drifts, ductility 

demands, cumulative dissipated energy demands, floor response spectra, 

standardized floor response time histories, or other similar parameters. For 

nonstructural components mounted directly at grade, these input engineering 

demand parameters are actually ground motion intensity measures and may 

be the same intensity measures used for Structural Performance Assessment. 

For nonstructural components and systems mounted within or suspended on 

the structure, the input engineering demand parameters must be generated by 

structural analysis. Appropriate input engineering demand parameters may 

be different for the several types of nonstructural components. 

A literature search will be performed to identify the input engineering 

demand parameters that have been suggested as appropriate for this purpose 

by various researchers and engineers. The Nonstructural Performance 

Products Team will compile these past recommendations into a 

comprehensive list, coordinate it with the inventory developed in Task NPP1, review and evaluate these suggestions, and extend the assignment of 

engineering demand parameters to each of the components and systems 

present in the inventory using engineering judgment. 

The product of Task NPP-4 will be an internal project report recommending 

the most appropriate input engineering demand parameters to be used for the 

performance assessment of various nonstructural components and systems. 

4.2.5 Develop Performance Database (NPP-5) 

Task NPP-5 will identify and obtain access to existing databases of seismic 

fragility data for nonstructural components. Such databases have been 

developed in the past by a number of groups including the Seismic 

Qualification Utilities Group, the Electric Power Research Institute, the 

Department of Energy, and others. Existing databases may be available from 

public agencies, proprietary sources, researchers, individual equipment and 

component vendors, and from test programs conducted in other countries 

(e.g., Canada). There might also be a substantial body of data available in 

the public domain in the form of reports on earthquake damage 

investigations. Much of this data has not yet been assembled into useful, 

searchable databases. 

An important part of Task NPP-5 is developing of a comprehensive 

electronic database of building nonstructural components, including seismic 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 47 

fragility data. It will be organized using the inventory catalog developed in 

Task NPP-1 and will include component description, experience data, 

sanitized proprietary data, seismic qualification data, actual recorded 

motions, design capacities, and observed performance. The same data 

organization can be used as the basis for archiving data on the performance 

of nonstructural components collected following future earthquakes. Where 

possible, uncertainty statistics regarding component fragility will be included 

in the database. 

4.2.6 Develop Nonstructural Performance Evaluation Protocols 

(NPP-6) 

Given the many types of nonstructural components for which performance 

characteristics must be determined to permit practical implementation of 

performance-based design, it is imperative that suppliers of these components 

be encouraged to develop the necessary performance data. To ensure that the 

performance data developed by these individual manufacturers and suppliers 

are consistent and are useful in the performance assessment and design 

processes, standardized testing protocols and certification procedures will be 

developed for shake table testing, cyclic drift testing and component response 

testing. 

The Nonstructural Performance Products Team will identify possible sources 

of funding for extensive testing. These sources will include equipment 

manufacturers, owners, insurers, and government agencies. Task NPP-6 

might include developing collaborative efforts between equipment buyers 

and equipment manufacturers. The NPP Team will develop a consensus on 

the technical description of testing protocols and will develop a means of 

obtaining certification of tested equipment for various seismic regions, 

building types and usage, and locations within buildings. 

Task NPP-6 will produce an internal project report that recommends 

standardized performance testing and certification procedures for 

nonstructural components. This data will be incorporated into the 

Performance Assessment Guidelines under Task NPP-1. 

4.2.7 Simplify Nonstructural Engineering Demand Parameters 

(NPP-7) 

Nonstructural components that are essentially rigid will experience the same 

motions as the ground or structure to which they are attached. For such 

components, the shaking at the attachment point can be used directly to 

estimate the level of damage sustained by the component. Flexible 

nonstructural components, however, will respond dynamically to the shaking 

at their point of attachments and may either amplify or attenuate the motions 
48 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

transmitted to them. To properly characterize the response and performance 

of such components, a dynamic analysis of the component or system of 

components is necessary to determine engineering demand parameters and 

levels of damage. However, given the large number of components present 

in a building of even moderate size, it is not practical to require such analyses 

except for a few, very important systems or components. 

Under Task NPP-7, the Nonstructural Performance Products Team will 

develop approximate, simplified procedures to estimate the response 

parameters for flexible nonstructural components, given a set of input 

engineering demand parameters. This effort is primarily intended for 

distributed systems where it is difficult, without significant calculations, to 

determine the response engineering demand parameters. For example, for a 

piping system it may be necessary to know the stress or strain in individual 

piping connections, given input engineering demand parameters such as 

relative anchor displacements or floor spectra. The critical response 

engineering demand parameters will be identified for significant components. 

Procedures will be developed for each significant type of nonstructural 

component that is amenable to analysis. 

Procedures will also be developed to determine generic response engineering 

demand parameters for a given set of input engineering demand parameters. 

For example, the procedures should permit estimates of the stresses or strains 

in a particular piping system given just the input engineering demand 

parameters, and without performing analysis of the system. Included in Task 

NPP-7 is development of estimates of uncertainty associated with 

determining the response engineering demand parameters for a given set of 

input without performing analysis. 

4.2.8 Develop Procedures for Computing Nonstructural Damage 

(NPP-8) 

Procedures will be developed in Task NPP-8 to convert the response 

engineering demand parameters for nonstructural components into damage 

measures. Damage measures could include loss of functionality, onset of 

leaking, failure of anchor bolts, and initial collapse of suspended ceilings, 

among others. This Task NPP-8 includes developing estimates of uncertainty 

associated with these damage measures. 

Also as a part of this effort, the relationships of input engineering demand 

parameters to performance measures will be evaluated. It is likely that for 

many nonstructural components (for example, rigid components and those 

components that are purely drift-sensitive) there will be a direct relationship 

between the input engineering demand parameters and the damage measure. 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 49 

For other nonstructural components, there may be only an indirect 

relationship (e.g., a piping system), requiring an intermediate step of 

analysis, per Task NPP-7. 

The deliverable for Task NPP-8 will be an interim project report 

recommending procedures to establish damage as a function of either 

intensity measure or input engineering demand parameter. These procedures 

for completing nonstructural damage will also be incorporated into the 

Performance Assessment Guidelines. 

4.2.9 Develop Nonstructural Loss Functions (NPP-9) 

NPP-9, the Nonstructural Performance Products Team will provide 

consultation and support to the Risk Management Products Team in 

developing procedures for constructing loss functions for nonstructural 

components and systems in buildings. The Nonstructural Performance 

Products Team will also support the Risk Management Products Team in 

developing standard or default loss functions for buildings of typical 

occupancies. 

4.2.10 Nonstructural Input to Model Building Studies (NPP-10) 

Under Task NPP-10, the Nonstructural Performance Products Team will 

provide assistance to the Risk Management Products Team in their 

development of assessments of case study buildings. Under Task SPP-6, the 

Structural Performance Products Team will develop a series of case study 

building structures, each consisting of one of the four candidate structural 

systems, designed for a high seismicity site using the design criteria of 

FEMA 450. In Task NPP-10, the NPP Team will develop specifications of 

the nonstructural build-out of these structures to represent a series of 

different occupancies. The Risk Management Products Team will then 

assess the performance of these buildings, using the structural performance 

assessment procedures, as they are developed, as a means of evaluating the 

effectiveness and usefulness of the procedures. 

4.3 Phase 1 Risk Management Products Tasks 

The Risk Management Products (RMP) tasks are divided into two basic 

types. The first type will be a series of detailed technical tasks related to 

developing mathematical procedures for integrating and aggregating the 

hazard, response and damage information, developed by the SPP and NPP 

Teams, to develop projections of loss. The Structural Performance Products 

and Nonstructural Performance Products efforts will result in: 
50 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

• Hazard curves that relate intensity of motion to probability of 

occurrence. 

• Response curves that relate the response of the structure and 

nonstructural components mounted on the structure to the hazard. 

• Damageability functions that relate the probable damage to the structure 

and nonstructural components and systems to the response. 

The Risk Management Products Team will work with the Structural 

Performance Products and Nonstructural Performance Products teams to 

develop derivation procedures for loss curves that relate probable casualties, 

repair/replacement costs and occupancy interruption time to building 

damage. The Risk Management Products Team will then develop procedures 

to integrate the hazard with the building response, the response with the 

damage and the damage with the loss curves to project performance. These 

procedures will express loss estimates in various terms, including average 

annual loss, expected loss for a given probability of occurrence, and 

maximum bounded loss for a given probability of occurrence. 

The second type of Risk Management Products tasks relates to 

communicating with stakeholders and decision-makers and ensuring that the 

means of expressing the performance outcomes of different design criteria 

decisions are useful to their decision-making processes. 

The Risk Management Products tasks will be performed by a technical team that 

includes a team leader and associate team leader; a researcher, and an engineer, 

each of whom will have expertise in structural reliability methods and loss 

estimation, a professional cost estimator, to assist with the process of loss 

estimation; a structural engineer; an architect; and a building regulator to assist 

with tasks related to communication of performance issues. Figure 4-3 is a 

schedule for the various tasks, which are explained in more detail in the 

following sections. 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 51 

Figure 4-3 Phase 1: Schedule for risk management product tasks. 

4.3.1 Develop Input to Performance Assessment Guidelines 

(RMP-1) 

The development of the Performance Assessment Guidelines will be jointly 

performed by the three Product Development Teams. The Risk Management 

Products Team will be responsible for developing those portions of the 

guidelines that relate to methods of expressing performance and procedures 

for calculating performance, including development of loss functions and 

integration of the hazard, structural response, nonstructural response, and 

structural and nonstructural damage curves with the loss curves to derive 

performance assessments (see also Appendix A, Seismic Performance 

Assessment). The Risk Management sections of the Structural Performance 

Assessment Guidelines will be developed in parallel with, and under the 

same schedule as the Nonstructural Performance and Structural Performance 

sections. 

4.3.2 Develop Structural Loss Functions (RMP-2) 

In Task RMP-2 procedures will be developed for converting discrete 

descriptions of structural damage, as represented by the structural damage 

measures in Task SPP-5, into losses. Losses will be expressed as probable 

repair cost given damage, probable interruption of occupancy time given 

damage, and probable serious injury or loss of life given damage. In 

addition, standard loss functions will be developed for each of the four 

candidate structural systems. 

The structural damage measures will consist of descriptions of structural 

damage. These may apply at the level of individual components (e.g., beam 
52 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

hinging, column spalling, brace buckling, wall cracking), at the element level 

(permanent interstory drift at a level), or other more global level (e.g., 

collapse). Structural damage measures will be expressed probabilistically in 

the form of damage functions that relate the probability of experiencing 

given damage as a function of the engineering demand parameters. Task 

RMP-2 will develop the procedures for converting the structural damage 

measures into meaningful loss terms for structural performance 

measurement. The procedures developed will then be implemented to 

develop standard structural loss functions for each of the four candidate 

systems. 

Task RMP-2 will begin with discussions between the Risk Management 

Products Team and Structural Performance Products Team as to how 

structural damage measures might be best formulated to provide effective 

and efficient indicators for eventual compilation of losses and performance. 

For example, it may be that component spalling is a better measure of repair 

costs than residual drift. Task RMP-2 will involve meetings with experts in 

construction, and will explore alternative approaches using the case study 

buildings. 

In the intermediate term, Task RMP-2 will focus on formulating the loss 

functions themselves. Appropriate indicators of loss will be developed for 

casualties (deaths and injuries), capital loss, and downtime. 

4.3.3 Develop Nonstructural Loss Functions (RMP-3) 

Task RMP-3 will develop standardized procedures to assess probable losses 

(casualties, capital loss, downtime) as a function of nonstructural damage. 

The nonstructural damage measures are descriptions of damage to 

nonstructural elements of buildings. These might apply to the individual 

component level (broken window), component assembly level (rate of 

leakage in a sprinkler riser or percent of windows in a wall likely to be 

broken), or system level (loss of function of an HVAC system). 

Nonstructural damage measures will be expressed probabilistically as 

damage functions that relate the probability of incurring various levels of 

damage either to levels of ground shaking, building or component response. 

Task RMP-3 will convert the nonstructural damage measures into 

meaningful terms for measuring performance. RMP-3 will also develop 

general procedures for determining nonstructural loss curves, as well as 

standardized default curves for common nonstructural components, 

assemblies and systems. 

The Risk Management Products Team will work with the Nonstructural 

Performance Products Team to determine how nonstructural damage 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 53 

measures might best be formulated for effective and efficient indication of 

losses and performance. For example: pipe leaks should be characterized at 

appropriate vertical locations in a facility since the exposure of contents to 

damage will be greater for leaks that occur high in the building. The level of 

refinement of the nonstructural damage measures will vary depending on the 

function of the facility. The HVAC system for an entire office building, for 

example, might be represented by a single damage measure, while for a 

hospital, individual zones and equipment might be assigned independent 

damage measures. 

Task RMP-3 will involve meetings with the Nonstructural Performance 

Products Team, consultation with experts in construction, and development 

of suggested strategies for the case study buildings. In the intermediate term, 

the effort will focus on the formulation of the loss curves themselves. 

Appropriate indicators of loss will be developed for casualties, capital loss, 

and downtime. These will apply strictly at the component or component 

assembly level. For example, a loss curve for a pump might consist of an 

expected central value and distribution of the percentage of total loss for the 

pump itself. Thus, a damage measure such as fracture of a flange on input or 

output lines might convert to an expected loss of 40 percent of the cost to 

entirely replace the pump. Note that this cost (and loss) does not include the 

implications of the overall amount of repair involved for the system or the 

building, which must also be considered. System losses and building losses 

will be accounted for in the loss aggregation process. Casualty indicators for 

nonstructural components or component assemblies might include falling 

hazards (lights) and/or functional hazards (smoke evacuation). Downtime 

indicators are time-related (e.g., hours, days, months), at either the 

component or component assembly level. 

4.3.4 Develop Model for Aggregating Losses (RMP-4) 

Task RMP-4 will develop and maintain a procedure for aggregating losses 

from the various structural and nonstructural components and integrating 

them over the hazard curve to express losses in terms of the basic 

performance parameters useful to stakeholders and decision-makers. This 

may include development of an electronic spreadsheet tool or other software 

to serve as the framework for performance evaluation. Task RMP-4 will be 

completed in conjunction with the Structural Performance Products and 

Nonstructural Teams Products teams. The result will be a basic conceptual 

model for calculating expected losses in a building, as illustrated in Figure 

4-4. 
54 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

Figure 4-4 Loss aggregation process. Note: PSHA = probabilistic seismic 

hazard analysis 

Specifically, this model for aggregating losses will: 

1. Utilize response spectra, and ground motion records representative of 

these spectra, scaled to various intensity levels. 

2. Incorporate nonlinear structural analysis to characterize the structural 

response to these ground motion representations and to develop functions 

that express the probable response of the structure as a function of 

intensity, in the form of various engineering demand parameters. 

3. Convert the engineering demand parameters into structural and 

nonstructural damage measures at the entire building, story, component, 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 55 

assembly, and system levels, expressed both deterministically and 

probabilistically. 

4. Convert structural and nonstructural damage measures into deterministic 

or probabilistic losses using loss functions based on the type of building 

structure and occupancy. 

5. Aggregate losses (casualties, capital loss, downtime) for the building 

using loss relationships that depend on the functional occupancy and use 

of the facility. 

The basic model for aggregating losses will be developed and tested using 

the case study buildings. 

Task RMP-4 is supported by a series of additional tasks, related to 

development of the basic methodology and procedures, and which are 

described further below. 

4.3.5 Formulate Conceptual Aggregation Procedures (RMP-5) 

Task RMP-5 will develop a preliminary performance assessment model that 

incorporates present methods of practice and will apply the model as a 

working platform by which to express performance in terms of probable 

losses. This is a critical short-term task involving: 

• Documenting the current practices for loss estimation for individual 

buildings. 

• Documenting the current research regarding loss estimation for 

individual buildings. 

• Expanding the preliminary format to encompass the conceptual 

relationships among the critical parameters (intensity measures, 

engineering demand parameters, damage measures, etc.). 

• Formulating a strategy for aggregating losses to determine building 

performance. 

• Preparing an internal report for use by the project team to further expand 

the model. 

Following completion of Task RMP-5, the preliminary aggregation 

procedures will be applied to the case study buildings developed under other 

tasks. This will enable improvements in the methodology to be developed on 

an incremental basis. 
56 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

4.3.6 Procedure for Aggregating Local Effects to Global (RMP-6) 

Task RMP-6 will develop a methodology to convert local measures of 

damage, for example buckled braces, cracked walls, or damaged sprinkler 

piping into a measure of total building loss. Interaction between individual 

local incidences of damage can significantly affect global loss, but the global 

loss is not simply the sum of losses that can be attributed to each individual 

element in the building, alone. As an example, the casualty rate in a building 

in which 10 percent of the columns have 10 percent or less of their original 

capacity might be relatively low if the damage is spread uniformly; or it may 

be relatively high if the damage is concentrated in a single floor. Also, 

capital losses are not simply the sum of the individual losses. Demolition 

and put-back costs, temporary relocation expenses, and soft costs can, in 

general, only be determined when the losses and performance implications 

are aggregated at the total building level. Consider, for example, that if a 

drywall partition is undamaged, it may have to be demolished and replaced, 

if structure behind this partition is damaged. Similarly, if both the structure 

and the partition are damaged, the partition need only be demolished and 

replaced one time. Task RMP-6 will explore these types of 

interdependencies and develop procedures for accounting for them in 

determining realistic estimates losses. 

A particularly challenging part of Task RMP-6 relates to restoration of 

service in a damaged facility and calculation of downtime. This will be 

highly dependent on the occupancy of the individual building and its 

tolerance to functioning in less than ideal circumstances. Some building 

occupancies will be much more tolerant of operating in damaged buildings, 

or buildings under repair, than will other occupancies. An office building 

might be able to function, albeit at a somewhat impaired level, fairly soon 

after incurring damage, whereas surgical and other environmentally sensitive 

spaces in a hospital would take longer to resume function as they are less 

tolerant of dust, inadequate HVAC, and other effects of damage. Minor 

repair to a pharmaceutical manufacturing facility could result in many 

months of occupancy interruption, while the facility is recertified by federal 

licensing authorities. Task RMP-6 will attempt to develop occupancyspecific relationships to model these tolerances. 

4.3.7 Develop Loss Integration Procedures (RMP-7) 

Task RMP-7 will integrate conventional economic, probabilistic, and 

financial procedures into the performance model to provide procedures 

capable of expressing performance in various formats, including annualized 

loss, deterministic scenario loss, and time-based hazard-related losses. 

Results of this task will also include explicit consideration of uncertainty and 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 57 

reliability. Task RMP-7 will develop the procedures necessary to generate 

losses in these formats and transform them from one form to another. 

In the short-term, Task RMP-7 will identify important procedures and the 

points at which they need to be incorporated into the overall model of Task 

RMP-4. The intermediate effort includes developing the basic procedures 

into modules within the model and testing the results. In the long-term, use 

of the basic procedures will be documented for implementation by 

practitioners. The loss integration procedures will have the capability to 

assess building performance in ways that are meaningful to the various 

stakeholders/decision-makers. 

4.3.8 Identify Stakeholder Needs (RMP-8) 

Task RMP-8 will continue the process of interfacing with stakeholder and 

decision-maker groups to understand their needs regarding consideration of 

building performance issues and the ways in which performance-based 

engineering products can be best related to their needs. 

Initially, Task RMP-8 will focus on identifying and initiating contact with single 

representatives of important stakeholder groups and engaging these individuals in 

ongoing participation in the performance-based design development process. At 

this point, four principal stakeholder categories have been identified as important 

groups with which to develop such interface: 

• Owners and managers 

• Societal and governmental interests 

• Financial managers 

• Design professionals, consultants, and researchers 

The first stakeholder category, owners and managers, are responsible for 

commissioning building design and construction, acquiring, maintaining 

and/or operating buildings and facilities. They make decisions about 

catastrophic risks that lead to action (or inaction) on a relatively narrow 

scale. Motivations generally spring from the best interests of the specific 

business or institution. Within the owner/manager category, three 

perspectives have been identified as important for interaction: investors, 

institutions and industry. 

This distinction between these categories reflects the assumption that 

different stakeholder groups characteristically have different motivations and 

criteria for decisions relative to catastrophic hazard mitigation. It is 

important to capture these distinctions (e.g., investment risk, operational 

risks, and market risks). 
58 4: Phase 1: Developing a Methodology – Technical Tasks FEMA 445 

The second stakeholder category includes those who represent broader 

societal and governmental interests. These individuals view catastrophic risk 

in a different context than do owners/managers. Their focus is on public 

safety and the impact of catastrophes on local/regional/national economies. 

Their decisions relate primarily to public policy, legislation and 

administration. The societal/governmental category is separated into three 

perspectives for focus groups: policy-makers, regulators, and special interest 

and advocacy groups. This reflects the different levels of sophistication, 

scope of decision-making and problem-solving ability, and types of criteria 

used by the three groups (e.g., policy-makers are making broadly applicable 

decisions for the community; regulators are considered more as “enforcers,” 

focused on the problem one building at a time; and special interest and 

advocacy groups “speak” for the interested and affected public). 

The third stakeholder category is primarily financial in nature. The 

owner/manager and the societal/governmental stakeholder categories have a 

direct stake in decisions about risks associated with buildings (e.g., protect 

the assets and protect the community interest). Financial stakeholders, 

however, have an indirect interest in building performance decisions made by 

others. Their decisions relate primarily to whether or not to assume risk 

associated with buildings and at what compensation level. The financial 

category might be represented by three focus groups: lenders, insurers, and 

securities packagers. 

Financial stakeholders differ from the previous two categories in that the 

stake is indirect: the concern is the financial risk associated with the decision 

to finance or assume risk, rather than in protection of people or owned assets. 

The three groups (lenders, insurers, and securities packagers) represent 

different views with respect to when and how the financial decisions are 

made, which in turn may impact how they characterize the risk and 

performance issues. Financial stakeholders tend to use very complex 

statistical and mathematical tools for decision-making. 

The fourth category of stakeholders includes design professionals, 

consultants, and researchers. The development of performance-based design 

capability has advanced primarily within this group, yet many are not 

familiar or conversant in this field. The design and consulting communities 

are the conduits through which performance-based design will be 

implemented. Awareness of performance-based design must be expanded to 

include input from both technical development personnel and those who 

implement performance-based design. 
FEMA 445 4: Phase 1: Developing a Methodology – Technical Tasks 59 

In the intermediate and longer terms, stakeholder categories will be expanded 

in order that Task RMP-8 activities may encounter broader perspectives. For 

each of the four stakeholder groups, Task RMP-8 will identify and recruit 

two to three additional representatives from the stakeholder groups. These 

groups will meet periodically with the Risk Management Products Team and 

others to monitor task progress and advise on the development of the Risk 

Management Products, particularly as it relates to Risk Management 

Products Task 8. Members of the Risk Management Products Team will 

serve as liaisons with the group representatives. Group members will be 

selected as much as possible from relatively high level and influential 

candidates. This will result in the development of longer term relations that 

will facilitate the transfer of performance-based design technology to the 

service and research stakeholders over time. 

4.3.9 Develop Standard Performance Level Characterizations 

(RMP-9) 

Task RMP-9 will develop procedures to express the risks that are the 

consequence of structural and nonstructural design decisions into formats 

that are as directly useful as possible to the various stakeholder and decisionmaker groups. In the short term, Task RMP-9 entails the assembly of basic 

information on the decision-making processes commonly used by various 

stakeholder groups. This information will be gathered in meetings with the 

initial stakeholder representatives and summarized in internal written 

summaries. In the intermediate term, the Risk Management Products Team 

will develop written pieces to illustrate basic options (e.g., annualized loss, 

scenario loss, time-based objectives) for discussion of them with the various 

groups. Based on feedback, preferred methods of expressing loss and 

performance will be determined. In the long term, the RPM Team will refine 

the basic options into standardized recommendations based on individual 

stakeholder perspectives. 

FEMA 445 5: Phase 2: Developing Procedures and Guidelines 61 

Chapter 5 

Phase 2: Developing 

Performance-Based Seismic 

Design Procedures and 

Guidelines

5.1 Phase 2 Objectives 

Chapters 3 and 4 of this report present the detailed work plan for Phase 1 of 

this Program Plan to develop a next-generation seismic performance 

assessment methodology and accompanying engineering guidelines. 

Engineers will be able to use those guidelines immediately in implementing 

performance-based design of new buildings and performance-based upgrade 

of existing buildings. To do this, however, they will first need to develop 

preliminary designs on which to conduct a performance assessment. Some 

engineers, particularly those with extensive experience in earthquakeresistant design, will be able to develop preliminary designs that are able to 

satisfy the desired performance objectives without extensive modification. 

Other engineers, however, will have difficulty developing preliminary 

designs that will be capable or nearly capable of meeting the desired 

performance objectives. Unless further guidance is provided, some engineers 

may find implementation of performance-based design to be time consuming 

and costly in many cases. 

Phase 2 this Program Plan, Developing Performance-Based Seismic Design 

Procedures and Guidelines, responds to this need, by developing additional 

tools needed to allow wider application of the next-generation performancebased design approach. Phase 2 will use and refine the Seismic Performance 

Assessment methodology developed in Phase 1, and enable next-generation 

performance-based design practice to become efficient and economical and 

thereby, acceptable and implementable. Specifically, Phase 2 will address 

additional issues and develop guidelines necessary to: 

• Assist decision-makers in selecting appropriate performance objectives 

for buildings of different occupancies. 

• Assist design professionals in identifying appropriate strategies for 

structural design of buildings to achieve specific performance objectives. 
62 5: Phase 2: Developing Procedures and Guidelines FEMA 445 

• Assist design professionals in developing efficient preliminary designs 

that will require relatively little iteration during the design process, 

• Quantify the performance capability of typical buildings designed to 

current prescriptive building codes, so that the lack of consistency in 

current performance and the advantages of performance-based design 

approaches is evident. 

• Provide for direct prescriptive performance-based design of simple 

buildings to achieve different performance objectives. 

5.2 Phase 2 Description of Work 

Phase 2 of this Program Plan will develop these additional tools and 

capabilities. Work to be performed under Phase 2 can be broadly classified 

into the following categories: 

• Identify the key decision-making parameters and processes used by 

different stakeholder groups. 

• Identify appropriate performance objectives for buildings of different 

occupancies. 

• Develop simple tools to assist decision-makers in selecting appropriate 

performance objectives. 

• Identify the performance consequences of various strategies for design, 

procurement, and construction. 

• Identify the performance consequences of various quality assurance 

strategies. 

• Develop simple tools for selecting appropriate design strategies to 

achieve different performance objectives. 

• Develop guidelines to assist stakeholders in taking advantage of the 

benefits of performance-based design, including considerations of 

maintenance. 

• Develop guidelines for design professionals to assist them in 

implementing performance-based design. 

5.3 Summary of Phase 2 Product Tasks 

Work in each technical area will be performed by one of the three Product 

Development Teams organized in Phase 1: the Structural Performance 

Products Team, the Nonstructural Performance Products Team, and the Risk 

Management Products Team. Though some changes in personnel might be 

appropriate, the members of the Product Development Teams will generally 
FEMA 445 5: Phase 2: Developing Procedures and Guidelines 63 

be the same as those empanelled in Phase 1. A summary of Phase 2 tasks to 

be performed by each of these teams is provided in the subsections that 

follow. Detail descriptions of Phase 2 tasks are provided in Chapter 6. 

5.3.1 Structural Performance Products Tasks 

Principal Phase 2 tasks to be performed by the Structural Performance 

Products (SPP) Team will include: 

• SPP-9: Identify the contributions to performance, as measured in life 

loss and injuries, direct repair and replacement cost and downtime, of 

various types of structural damage for buildings of different structural 

systems, occupancies, and eras and styles of construction. 

• SPP-10: Identify the effects of various structural parameters, including 

stiffness, strength, ductility, and damping, on life loss and injuries, direct 

repair and replacement costs and downtime in buildings of various 

occupancy, structural systems and eras and styles of construction. 

• SPP-11: Identify preferred structural strategies for achieving various 

performance objectives in new buildings of different occupancy and 

structural systems. 

• SPP-12: Identify preferred structural strategies for upgrade of existing 

buildings of different eras and construction types to achieve various 

performance objectives in buildings of different structural systems. 

• SPP-13: Prepare structural input to performance-based design guidelines 

for performance-based design. 

5.3.2 Nonstructural Performance Products Tasks 

Principal Phase 2 tasks to be performed by the Nonstructural Performance 

Products team will include: 

• NPP-11: Identify the contribution to performance, as measured in life 

loss and injuries, direct repair/replacement cost, and downtime of various 

nonstructural components and systems in buildings. Different eras of 

construction and different design and installation criteria will be 

considered, as well as the effects of different occupancies and structural 

characteristics. 

• NPP-12: Identify the effectiveness of current code procedures in 

reducing the consequences of nonstructural performance in terms of life 

loss and injuries, direct repair/replacement costs, and downtime in 

buildings of different occupancies, and structural system types. 

• NPP-13: Identify the effectiveness of various alternative design 

strategies for reducing life loss and injuries, direct repair and 
64 5: Phase 2: Developing Procedures and Guidelines FEMA 445 

replacements costs, and downtime consequences of nonstructural 

component and system performance in buildings of different 

occupancies, structural systems, and eras of construction. 

• NPP-14: Develop preferred nonstructural design strategies for achieving 

various performance objectives in buildings of different occupancy 

types, structural systems, and eras of construction. 

• NPP-15: Prepare input to performance-based design guidelines. 

5.3.3 Risk Management Products Tasks 

Principal Phase 2 tasks to be performed by the Risk Management Products 

(RMP) Team will include: 

• RMP-10: Identify the key performance concerns of different stakeholder 

communities and types of decision-makers. 

• RMP-11: Identify the key performance parameters for buildings of 

different occupancies. 

• RMP-12: Identify the preferred decision-making models of different 

types of decision-makers. 

• RMP-13: Develop simplified decision-making aids that will assist 

decision-makers to select appropriate building performance objectives. 

• RMP-14: Explore the performance capability of typical buildings 

designed in accordance with current building code procedures using 

typical contemporary procurement, construction and quality assurance 

practices and comparing these against the needs of various stakeholders. 

• RMP-15: Explore the performance capability of typical existing 

buildings designed in accordance with the standards prevalent during 

different eras and in different regions of the nation, for buildings of 

various occupancies and structural system types. 

• RMP-16: Develop guideline documents to assist various decision-maker 

and stakeholder groups to achieve the maximum possible benefit from 

performance-based design. 

• RMP-17: Provide input to performance-based engineering guidelines for 

seismic design. 

The Risk Management Products Team will play a significant role in support 

of the work performed by the Nonstructural Performance Products and 

Structural Performance Products Teams. Much of the work performed by 

these two teams will consist of exploring the effects of various design 

strategies on building performance capability. This will require that a series 
FEMA 445 5: Phase 2: Developing Procedures and Guidelines 65 

of model building designs be developed and their performance capability 

assessed with respect to the performance of both structural and nonstructural 

components and systems. It is anticipated that the Risk Management 

Products Team will implement these performance assessments using the 

seismic performance assessment methodology developed in Phase 1. 

5.4 Phase 2 Project Management 

Project management will be performed under the same management structure 

described for Phase 1, and illustrated in Figure 3-1. Project management and 

oversight will be conducted using the same procedures and the same 

committees, including a Project Management Committee, Project Technical 

Committee, and Project Steering Committee. 

5.5 Phase 2 Projected Program Costs and Schedule 

Phase 2 of this Program Plan is intended to be accomplished in five years, 

contingent on the availability of sufficient levels of funding to enable the 

necessary work to be performed in the planned sequence. Figure 5-1 

presents an overall summary of tasks and schedule for the originally planned 

Phase 2 work. Detailed descriptions of Phase 2 tasks are provided in Chapter 

6. 

The original Phase 2 total projected project costs were estimated at 

approximately $10 million in 2004 dollars. Estimates of personnel and other 

costs associated with the Phase 2 tasks of this Program Plan have been 

developed using prevailing labor costs common to projects of this type at the 

time this plan was prepared, and do not include escalation due to changes in 

the value of money, labor rates, internal government costs, or inflation. 

Table 5-1 presents an overall estimate for Phase 2 broken down by Product 

Development Area. Table 5-2 presents a detailed breakdown of these costs 

by specific task and shows how these costs were intended to be distributed 

throughout the program. 

Table 5-3 and Table 5-4 present an overall picture of the Phase 2 reducedscope program prepared at the request of FEMA. The budget for the 

reduced-scope program is approximately 50% of that for the original 

program. Table 5-3 presents an estimate for the reduced scope costs for 

Phase 2 broken down by Product Development Area, and Table 5-4 presents 

a detailed breakdown of reduced-scope costs by specific tasks. 
66 5: Phase 2: Developing Procedures and Guidelines FEMA 445 

Figure 5-1 Summary of tasks and schedule for Phase 2: Developing Performance-Based Seismic Design 

Procedures and Guidelines. Phase 2 begins upon completion of Phase 1. 
FEMA 445 5: Phase 2: Developing Procedures and Guidelines 67 

Table 5-1 Original Projected Program Costs by Product Development Area, 

Phase 2: Development of Performance-Based Seismic Design Guidelines 

Product Development Area/Cost Element Cost ($1,000) 

Structural Performance Products $2,635 

Nonstructural Performance Products 1,440 

Risk Management Products 2,200 

Project Management, Administration, Oversight (Review), and 

Other Costs (Travel, Communications, Supplies and Equipment) 3,375 

Total $9,650 

Table 5-2 Original Phase 2 Projected Program Costs by Task and Year ($1,000) 

Task Year 1 Year 2 Year 3 Year 4 Year 5 Total 

SPP-9 Identify Structural Contribution to Performance $560 - - - - 560

SPP-10 Identify Effect of Structural Parameters - 520 255 - - 775

SPP-11 Identify Preferred Structural Strategies for New Buildings - - 330 220 - 550

SPP-12 Identify Preferred Structural Upgrade Strategies - - 220 220 110 550

SPP-13 Provide Input to Design Guidelines - 50 50 50 50 200

SPP Total 560 570 855 490 160 2,635

NPP-11 Identify Nonstructural Performance Contributions 560 - - - - 560

NPP-12 Identify Effectiveness of Current Practice - 100 - - - 100

NPP-13 Identify Effectiveness of Alternative Strategies - 110 220 - - 330

NPP-14 Identify Preferred Strategies - - 80 170 - 250

NPP-15 Provide Input to Design Guidelines - 50 50 50 50 200

NPP Total 560 260 350 220 50 1,440

RMP-10 Identify Key Performance Concerns 170 80 - - - 250

RMP-11 Identify Key Performance Parameters 170 80 - - - 250

RMP-12 Identify Preferred Decision-Making Models 170 80 - - - 250

RMP-13 Develop Simplified Decision Tools 200 - - - - 200

RMP-14 Evaluate Performance Capability of Present Codes 100 - - - - 100

RMP-15 Evaluate Performance Capability of Typical Existing Buildings 225 225 - - 450

RMP-16 Develop Stakeholder Guides 0 200 200 100 500

RMP-17 Provide Input to Design Guidelines 50 50 50 50 200

RMP Total 810 515 475 250 150 2,200

Project Management, Oversight & Administration 475 475 475 475 475 2,375

Other Direct Costs 200 200 200 200 200 1,000

Total $2,605 $2,020 $2,355 $1,635 $1,035 $9,650
68 5: Phase 2: Developing Procedures and Guidelines FEMA 445 

Table 5-3 Reduced-Scope Projected Program Costs by Product Development Area, 

Phase 2: Development of Performance-Based Seismic Design Guidelines 

Product Development Area/Cost Element Cost ($1,000) 

Structural Performance Products $1,140 

Nonstructural Performance Products 650 

Risk Management Products 1,070 

Project Management, Administration, Oversight (Review), and 

Other Costs (Travel, Communications, Supplies and Equipment) 2,140 

Total $5,000 

Table 5-4 Reduced-Scope Phase 2 Projected Program Costs by Task and Year ($1,000) 

Task Year 1 Year 2 Year 3 Year 4 Year 5 Total 

SPP-9 Identify Structural Contribution to Performance $250 - - - - 250

SPP-10 Identify Effect of Structural Parameters - 260 50 - - 310

SPP-11 Identify Preferred Structural Strategies for New Buildings - - 130 100 - 230

SPP-12 Identify Preferred Structural Upgrade Strategies - - 100 100 50 250

SPP-13 Provide Input to Design Guidelines - 25 25 25 25 100

SPP Total 250 285 305 225 75 1140

NPP-11 Identify Nonstructural Performance Contributions 250 - - - - 250

NPP-12 Identify Effectiveness of Current Practice - 50 - - - 50

NPP-13 Identify Effectiveness of Alternative Strategies - 50 100 - - 150

NPP-14 Identify Preferred Strategies - - 40 60 - 100

NPP-15 Provide Input to Design Guidelines - 25 25 25 25 100

NPP Total 250 125 165 85 25 650

RMP-10 Identify Key Performance Concerns 80 40 - - - 120

RMP-11 Identify Key Performance Parameters 80 40 - - - 120

RMP-12 Identify Preferred Decision-Making Models 80 40 - - - 120

RMP-13 Develop Simplified Decision Tools 80 - - - - 80

RMP-14 Evaluate Performance Capability of Present Codes 80 - - - - 80

RMP-15 Evaluate Performance Capability of Typical Existing Buildings - 100 100 - - 200

RMP-16 Develop Stakeholder Guides - 0 100 100 50 250

RMP-17 Provide Input to Design Guidelines - 25 25 25 25 100

RMP Total 400 245 225 125 75 1070

Project Management, Oversight & Administration 250 250 250 250 240 1240

Other Direct Costs 100 200 200 200 200 900

Total $1,250 $1,105 $1,145 $885 $615 $5,000
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 69 

Chapter 6 

Phase 2: Developing 

Performance-Based Seismic 

Design Procedures and 

Guidelines— Product Tasks

6.1 Phase 2 Structural Performance Products Tasks 

The purpose of the Phase 2 Structural Performance Products tasks is to 

develop recommendations for selection and design of structural systems that 

can be effectively used to achieve a range of performance goals in new 

building design and existing building upgrade projects. Structural systems 

affect the performance of buildings—as measured in casualties, economic 

loss related to repair and replacement and occupancy interruption—through 

two primary behaviors. First, structural systems themselves are vulnerable to 

damage, and therefore can directly cause casualties, require repair, and result 

in unsafe conditions that prevent building occupancy and use. Second, 

structural systems transmit demands to nonstructural components and 

systems, in the form of accelerations and interstory drifts, in turn damaging 

these nonstructural building components. Design of structural systems to 

achieve desired performance, whether in new buildings or upgrade of 

existing buildings must consider both of these effects. Therefore, the 

Structural Performance Products Team will work closely with the 

Nonstructural Performance Products Team in developing appropriate 

strategies. 

Structural performance products tasks include identifying the importance of 

structural damage as a contributor to the basic performance metrics, and 

evaluating the effectiveness of various structural design strategies such as 

stiffening, strengthening, improving ductility, etc., to reducing building 

losses. Task SPP-8 will identify preferred combinations of these structural 

parameters to achieve desired performance goals. Tasks will culminate with 

development of procedures for selection of appropriate structural design 

strategies to achieve desired performance goals, development of preliminary 

design criteria that will enable designers to efficiently implement 

performance-based design methods, and presentation of the results of these 

tasks in Performance-based Design Guidelines. 
70 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

Figure 6-1 presents a proposed schedule for the Phase 2 Structural 

Performance Product tasks, which are described in more detail in the 

following sections. 

Figure 6-1 Phase 2: Schedule for structural performance products tasks 

6.1.1 Identify Structural Contribution to Performance (SPP-9) 

Task SPP-9 will investigate the relationship between structural performance 

and overall building performance. Since it is already clear that the 

performance of buildings with fragile structural systems, such as 

unreinforced masonry buildings and nonductile concrete frame buildings, 

will be dominated by the high potential for structural collapse and total 

building loss, Task SPP-9 will focus on buildings designed to modern code 

requirements and which have low risk of collapse. Task SPP-9 will be run in 

parallel with Task NPP-10, and will extract data from the evaluations 

performed under that task to identify the extent that structural damage in 

modern well-designed structures affects overall building performance. This 

information will be used to guide later tasks that are focused on developing 

design strategies intended to improve the seismic performance characteristics 

of buildings. 

6.1.2 Identify Effect of Structural Parameters (SPP-10) 

Task SPP-10 will identify the effect that basic structural design parameters—

that is stiffness, strength, period, damping and ductility—have on overall 

building performance. Increases in structural stiffness, for example, reduce 

interstory drift, but can result in higher floor response accelerations and 

higher structural forces at low levels of structural response. This might 

reduce damage to drift-sensitive nonstructural components, but increase 

damage to acceleration-sensitive components as well as to structural 

components. Increased strength may reduce damage to structural 
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 71 

components, but transmit higher floor accelerations to nonstructural 

components. 

In this task, a series of case-study buildings will be developed, and then 

subjected to a series of parametric performance evaluations in which 

structural design parameters (e.g., stiffness, strength, and damping) are 

varied. The effect on overall building performance, as well as the individual 

performance of structural and nonstructural elements, will be evaluated. 

Relationships between these various parameters and building performance 

will be developed for use in preliminary design to determine appropriate 

target values for these parameters. 

6.1.3 Identify Preferred Structural Strategies for New Buildings 

(SPP-11) 

Task SPP-11, along with the results of Tasks SPP-9 and SPP-10, will be 

evaluated to develop procedures for identifying appropriate design strategies 

and preliminary design procedures for new building construction. Strategies 

will address selection of appropriate systems, and the preliminary design 

procedures will address configuration and proportioning of the system in a 

manner that is consistent with the selected performance objectives. 

6.1.4 Identify Preferred Structural Upgrade Strategies (SPP-12) 

Task SPP-12 is parallel to Task SPP-11 and will develop procedures for 

identifying appropriate design strategies and preliminary designs for the 

seismic upgrade of existing buildings. The principal difference between 

Task SPP-12 and Task SPP-11 is that, in addition to providing protection for 

the new structure and the nonstructural components and systems, the upgrade 

systems must be sufficient to protect the existing structural systems, which 

are often fragile. Task SPP-12 will entail performance evaluations of a series 

of case-study existing buildings with a number of different upgrade 

strategies, so that the effectiveness of these strategies on the performance of 

the building as a whole can be determined. 

6.1.5 Provide Input to Design Guidelines (SPP-13) 

Task SPP-13 will develop structural sections of Performance-based Design 

Guidelines focused on developing preliminary designs of structural systems 

in new building construction and for existing building upgrades, to satisfy 

various performance objectives. The Performance-based Design Guidelines 

will include information on characterizing earthquake hazards, selecting an 

appropriate structural upgrade or design strategy and developing a 

preliminary structural design. The Seismic Performance Assessment 

guidelines developed under Phase 1 will be used to confirm that the 
72 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

preliminary design is actually capable of providing the desired performance 

and as a tool to adjust preliminary designs, as necessary to achieve desired 

performance. 

6.2 Phase 2 Nonstructural Products Tasks 

The purpose of the Phase 2 Nonstructural Performance Products tasks is to 

develop recommendations for design and installation practices that can be 

effectively used to achieve a range of performance goals in new building 

design and existing building upgrade projects. One of the significant 

problems associated with doing this is that there is no clear understanding as 

to how significantly nonstructural damage contributes to casualties, 

economic loss, and occupancy/use loss. There is a general, but unverified, 

belief that structural damage (as opposed to nonstructural damage) is the 

primary contributor to casualties. Similarly, there is a belief that 

nonstructural losses tend to dominate repair costs, particularly for moderate 

levels of shaking intensity. It is not clear whether structural or nonstructural 

damage is most significant to occupancy interruption losses. Before an 

effective strategy for mitigating potential losses due to nonstructural damage 

can be developed, it is important to quantify the contribution of nonstructural 

damage to these various types of building losses. 

Presuming that the contribution of nonstructural damage to potential losses is 

significant, it next becomes important to develop effective strategies to 

improve building performance through mitigation of these losses. Several 

basic approaches are hypothetically possible, including altering the structural 

system to moderate the demands on the nonstructural components and 

systems, reducing the damageability of these components and systems 

through improved design practices, as well as the basic procedures for 

procuring these building components, which presently relies heavily on field 

design by the installation contractor. The effectiveness of each of these 

approaches needs to be evaluated to recommend appropriate strategies as part 

of the Performance-based Design Guidelines. Further, since these 

nonstructural effects are likely to be dependent on the seismicity at the 

building site and the type and age of building construction, Phase 2 will 

undertake an extensive parametric study, as described in the individual NPP 

Tasks outlined below. Figure 6-2 provides a projected summary schedule for 

these tasks. 
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 73 

Figure 6-2 Phase 2: Nonstructural Performance Products task schedule. 

6.2.1 Identify Nonstructural Performance Contributions (NPP-11) 

Task NPP-11 will identify the contribution of nonstructural damage to 

casualties, repair costs, and occupancy/use interruption times in buildings of 

various types and eras of construction, and in several seismic zones. 

Performance, measured by estimated losses will be evaluated for a series of 

case study buildings considering two basic conditions for each building. The 

first condition consists of the building with nonstructural components and 

finishes present, but with these components being seismically rugged, (i.e., 

not prone to damage). The second case consists of the same buildings, but 

with nonstructural components and systems that have damage potential that 

is more typical of those found in real buildings. The projected difference in 

losses between the buildings with rugged nonstructural components and 

those with fragile nonstructural components will indicate the extent that the 

nonstructural components contribute to these various performance measures. 

It is important to note that this same data cannot be attained by evaluating the 

performance of bare shell buildings and comparing it against performance of 

buildings that have been built out with nonstructural components. This is 

because there may be significant costs associated with the demolition and 

repair of nonstructural components that were not damaged, but which must 

be removed and then replaced in order to allow structural repairs to occur. 

For the purposes of Task NPP-11, it will probably not be necessary to 

evaluate the performance of a large number of buildings. Rather, the 

performance of a range of structural types will be evaluated, including 

structurally fragile and structurally rugged building types, structurally stiff 

and structurally flexible building types, and nonstructural systems that are 

relatively rugged, as represented by current practice in regions of high 

seismicity, and those that are relatively fragile, as represented by other types 

of practice. 
74 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

A range of performance assessments will be performed. It will be important 

to understand the relationship of nonstructural performance relative to 

structural performance at different ground motion intensity levels. Thus, in 

addition to performing probabilistic evaluations that consider the entire range 

of hazards, it will be important to conduct scenario evaluations that permit 

examination of the relative contributions of structural and nonstructural 

damage at different intensity levels. 

The Structural Performance Products Team will assist in Task NPP-11 by 

developing structural designs for evaluations. The Risk Management 

Products Team will assist by performing the evaluations. The Nonstructural 

Performance Products Team will take the lead in developing the 

nonstructural components and systems inventories for these structures and 

will interpret the results of the studies to obtain data that are useful for 

formulation of design recommendations. 

6.2.2 Identify Effectiveness of Current Practice (NPP-12) 

Task NPP-12 will determine the effectiveness of current design, 

procurement, and installation practices for mitigating losses related to the 

performance of nonstructural components and systems. Information obtained 

from Task NPP-12 will identify current practices that are deficient in 

mitigating earthquake losses and that should be changed to achieve enhanced 

nonstructural performance. 

Under Task NPP-12, the Nonstructural Performance Products Team will 

direct a series of evaluations of buildings of different occupancies that have 

different nonstructural components with different levels of susceptibility to 

damage, and which are representative of current design and installation 

practices for the various regions of seismicity. Structural systems of various 

stiffness and strength levels, as well as damage-resistant systems such as 

seismic isolation and energy dissipation, will also be evaluated. Potential 

losses due to nonstructural component and system performance for a variety 

of shaking intensities will be evaluated, as will aggregate losses obtained by 

summing the projected loss at each intensity level factored by the probability 

of that intensity occurring. Evaluations will be performed for the same 

buildings assuming both rugged and fragile nonstructural systems and 

components. The difference in predicted performance relating to robust 

nonstructural procedures and standard nonstructural installation practices 

provide data on the effectiveness of current practice in mitigating losses and 

improving performance. Evaluation of the data will also allow the 

nonstructural components that contribute the most to losses to be identified. 
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 75 

These data will allow effective strategies to be developed for mitigating 

losses. 

6.2.3 Identify Effectiveness of Alternative Strategies (NPP-13) 

There are several potential alternative strategies for reducing the losses that 

result from damage to nonstructural components and systems. These 

include: 

• For existing buildings, identifying those nonstructural components and 

systems, the upgrade/replacement of which could result in significant 

enhancement in building performance. 

• Using contemporary approaches to seismic design, specification, and 

procurement of nonstructural components and systems, but significantly 

increasing the level of inspection, similar to that provided by California 

Office of Statewide Health Planning and Development (for hospitals), to 

ensure that systems and components are actually installed properly. 

• Using more damage-resistant details for selected components and 

systems, such as installation of interior partitions in a manner that can 

better accommodate interstory drift. 

• Adopting industrial-type design, procurement, and installation practices 

for the installation of vulnerable systems and components, such as piping 

systems. Under these practices, rather then requiring contractors to fieldroute piping, conduit, ductwork, and similar items and brace them using 

generic support specifications, the building design team would prepare 

routing plans for these systems that would indicate all required support 

and bracing locations and details. Inspection would be at a level 

comparable to that required for structural system construction. 

• Using structural systems that minimize the demands on nonstructural 

components and systems, such as seismic isolation and energy 

dissipation. 

Task NPP-13 will include study the cost effectiveness of each of these 

strategies, as well as others identified by the Nonstructural Performance 

Products Team. Information developed in Task NPP-13 will lead to practical 

and effective recommendations for improving performance by reducing 

losses resulting from nonstructural performance in the Seismic Performance 

Assessment guidelines. 

6.2.4 Identify Preferred Strategies (NPP-14) 

Using information obtained from Task NPP-13, Task NPP-14 will identify 

those strategies for mitigating damage to nonstructural components and 
76 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

systems that are most appropriate for achieving various performance 

objectives in various regions of seismicity. Inherent in this task is the 

realization that it is probably not necessary to use the same care in the 

installation of nonstructural components and systems in all buildings. For 

example, if nonstructural performance is found to be a relatively small 

contributor to the risk of casualties, but a significant contributor to economic 

loss relating to damage repair costs in moderate earthquakes, then strategies 

that minimize these costs would be identified based on the information 

obtained from Task NPP-13. The data from Task NPP-14 will be used to 

formulate recommendations contained in the Performance-based Design 

Guidelines. 

6.2.5 Provide Input to Design Guidelines (NPP-15) 

Task NPP-15 will develop the Performance-based Design Guidelines related 

to the design, procurement, installation, quality assurance, and maintenance 

of nonstructural components and systems in buildings of varying 

occupancies and for varying performance objectives. The Performancebased Design Guidelines will be formatted to present a menu of strategies for 

mitigating nonstructural-related losses, as appropriate to achieving different 

performance goals in regions of different seismicity. The guidelines will 

enable engineers to choose between specifying rugged installation of 

nonstructural components and systems, or selecting a structural system that 

minimizes demands on these components and systems and will consider the 

desired performance and seismic environment in which the building is 

constructed. 

6.3 Phase 2 Risk Management Products Tasks 

The Risk Management Products tasks will: 

• Quantify the performance needs of various building stakeholder and 

decision-maker groups so that the best methods of expressing their needs 

can be identified. 

• Explore how effective current and past building design and construction 

practices have been in meeting these needs. 

• Develop decision-making tools and guidelines for decision-makers to 

assist them in selecting appropriate performance objectives as the design 

criteria for their buildings. 

Much of the work of the Risk Management Products Team will consist of 

outreach to various stakeholder and decision-maker communities to 

determine the most important aspects of building seismic performance to 

them and how they prefer to conceptualize and quantify these performance 
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 77 

issues. This will be followed by identified optimal or desired building 

performance objectives that are important to various stakeholders and 

decision-makers, considering the cost of mitigation. 

Another major area of work will consist of exploring how well current and 

past practices in building design and construction meet the desired 

performance goals. Much of this work will be done by conducting 

performance evaluations of different case study model buildings that 

represent buildings of different occupancies, constructed in different eras, 

and located in different seismic environments to determine the losses 

associated with these buildings. In performing tasks related to defining the 

performance capability of current and past practices, the Risk Management 

Products Team will work closely with the Structural and Nonstructural 

Performance Products Teams, who will define the basis for consideration of 

performance in terms of identifying the typical structural and nonstructural 

environment of buildings of different eras and occupancies. 

Finally, the Risk Management Products Team will develop a series of tools 

and guidelines that will assist decision-makers in selecting the appropriate 

performance goals for buildings of different occupancies. These tasks are 

described in greater detail in the following sections. Figure 6-3 presents a 

projected schedule for these tasks. 

Figure 6-3 Phase 2: Schedule for Risk Management Products tasks. 

6.3.1 Identify Key Performance Concerns (RMP-10) 

Virtually everyone is a stakeholder in building seismic performance. 

Everybody lives and works in a building and therefore is at risk of personal 
78 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

injury or life loss if buildings are not adequately designed and constructed. 

Beyond this basic safety issue, individuals are at direct economic risk if their 

workplaces are damaged and their businesses unable to function. An indirect 

risk is disruption of a community’s infrastructure that results in a general 

economic decline in a region. Earthquake damage can result in a general loss 

of housing, healthcare, and other essential services. 

Despite the fact that nearly everyone’s health and welfare makes them a 

building seismic performance stakeholder, relatively few can have direct 

affect, as decision-makers, on the seismic performance basis used to design 

and construct individual buildings. Building developers, building owners, 

building officials and some long-term building tenants are direct decisionmakers in that they can direct design professionals to design or upgrade 

buildings to meet specific performance criteria. Property casualty insurers, 

mortgage lenders, corporations and commercial tenants, and the general 

public are indirect decision-makers. Typically, these groups cannot directly 

decide the criteria that design professionals will implement in design or 

upgrade of a facility; however, they can apply economic incentives to the 

decision-makers. Casualty insurers, for example, may offer preferential 

insurance premiums to buildings with certain performance characteristics, 

while declining to insure buildings with other characteristics. Mortgage 

lenders may similarly require that borrowers carry earthquake insurance on 

buildings with poor seismic performance attributes or choose not to make 

loans at all. Prospective building purchasers and tenants can affect the 

performance criteria selected by direct decision-makers by placing higher 

value in terms of purchase price and rent on properties that have superior 

seismic performance capability. 

The amount of concern and influence these various indirect decision-makers 

have and exercise varies, depending on building occupancy, geographic 

region, and the likelihood that earthquakes will occur. In regions of high 

seismicity, for example, nearly all indirect decision-makers are sufficiently 

concerned with seismic performance issues to have some impact on the 

decisions made by the direct decision-makers. In regions of moderately high 

seismicity, a few indirect decision-makers (such as lenders or insurers) may 

affect decisions. In regions of low seismicity, however, not even direct 

decision-makers may make conscious consideration of seismic criteria. 

In Task RMP-10, the Risk Management Products Team will hold a series of 

workshops and interviews with representatives of various decision-maker 

and stakeholder communities to determine the extent to which these 

communities have specific seismic performance concerns with buildings of 

different occupancies, and to identify what these concerns are and the 
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 79 

strength of these concerns with regard to the community willingness to affect 

eventual decisions. This information will be used to guide direct decisionmakers when making building performance decisions. 

6.3.2 Identify Key Performance Parameters (RMP-11) 

As described in Chapter 2, the primary measures of performance—the risks 

of casualties, direct financial loss related to damage repair and facility 

replacement costs and loss of occupancy or use of a building—can be 

expressed in a variety of formats, depending on the needs of the individual 

decision-maker. These include: 

• Expected (median) value of the loss over a defined number of years. 

• Average (mean) loss per year. 

• Mean probability that losses would exceed a given level in a defined 

period of time. 

In addition, it is possible to express the uncertainty associated with projection 

of these potential losses in a variety of formats. Some decision-makers do 

not like to make decisions considering uncertainty, but would rather make 

decisions based on maximum values or expected values. The confidence 

level associated with the loss projections could be explicitly stated, or the 

projected losses could be stated in terms of bounding conditions such as an 

expected value, and 10 percent and 90 percent confidence of nonexceedance 

values. 

There is no unique best set of parameters to express these risks of loss and 

the associated confidence in the projections that will be preferable to all 

decision-makers or stakeholders. Lenders, for example, as an industry, have 

adopted Probable Maximum Loss as the preferred parameter for making 

choices on seismic performance. Probable Maximum Loss is an expression 

of the repair cost, at a 90% probability of nonexceedance, for earthquake 

shaking with a 10% chance of exceedance in 50 years. The insurance 

industry generally prefers to evaluate probable losses in terms of an average 

annualized loss that allows them to look at the probable losses to a large 

portfolio of insured properties on a uniform basis. Individual corporate risk 

managers and building owners often prefer to view losses in terms of the 

likely outcome given that a specific earthquake is experienced. 

In this task, the Risk Management Products Team will hold a series of 

focused interviews with representative stakeholders and decision-makers to 

determine preferred parametric expressions of earthquake risk for use in 

making performance choices. This information will provide input to the 

development of Performance-Based Design Guidelines. It will also provide 
80 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

input into the formulation of Stakeholder Guides, developed by the Risk 

Management Products Team, and which will provide guidance to decisionmakers on how to make appropriate building performance choices when 

developing, occupying, or upgrading buildings. 

6.3.3 Identify Preferred Decision-Making Models (RMP-12) 

Not all decision-makers will make building performance decisions in the 

same way. Generally, the decision will involve weighing the potential costs 

and benefits of obtaining improved seismic performance, then determining a 

level of investment that balances these costs and benefits, while also 

considering other potential uses of the funds. Many decision-makers will 

determine that seismic performance is not an important consideration worthy 

of the expenditure of funds, given other risks and needs that they face. For 

these decision-makers, the selection of an appropriate level of building 

performance is easy—they will select the minimum that regulatory 

authorities will permit. Other decision-makers, those who determine that 

seismic performance is a significant issue, may wish to perform a costbenefit study that weighs the benefits to be gained from design for improved 

building performance against the costs of designing for it, and then select an 

optimum level of performance with respect to cost. Still other decisionmakers may determine that certain building performance outcomes will result 

in total ruin of their enterprise, and will select performance objectives that 

reduce the risk of such ruin to an acceptable level, regardless of the cost 

involved. 

In Task RMP-12, the Risk Management Products Team will meet with 

representative decision-makers and determine the typical decision-making 

processes used by different types of decision-makers. This information will 

be used to guide the development of simplified decision-making tools and the 

development of Stakeholder Guides. 

6.3.4 Develop Simplified Decision Tools (RMP-13) 

The basic Seismic Performance Assessment procedures described in 

Chapters 2, 3, and 4 express performance in terms of the risk of casualties, 

financial loss relating to repair and replacement of damaged buildings, and 

occupancy interruption. In Task RMP-13, the Risk Management Products 

Team will develop simplified cost-benefit approaches that decision-makers 

can use to determine appropriate performance objectives for a building, given 

their individual circumstances and risk tolerance. A number of simplified 

tools for performing such analyses have been developed. The California 

Seismic Safety Commission published a cost-benefit risk methodology, 

Earthquake Risk Management: A Toolkit for Decision-Makers (EQE, 1999), 
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 81 

that allowed cost-benefit studies to be performed with information on the 

probable losses incurred for two levels of earthquake shaking. Porter (2004) 

presented a simplified methodology in which a cost-benefit analysis could be 

made based on estimated losses for a single level of earthquake shaking. 

Under Task RMP-13, the Risk Management Products Team will review these 

and other methodologies, including risk-of-ruin decision models, and select 

one or more simplified models for further development and presentation in 

the Stakeholders Guides. 

Regardless of the specific cost-benefit model selected under Task RMP-13, 

an important consideration will be how to convert occupancy interruption 

time into financial loss. It is very difficult to do this on a general basis 

because the financial consequences of building occupancy interruption are 

dependent on the circumstances of the individual building occupants. The 

Risk Management Products Team will develop a simplified procedure to 

assist the decision-maker in identifying and quantifying the financial 

consequences of building occupancy loss so that these can be used in 

whatever decision-making process he or she prefers. 

6.3.5 Evaluate Performance Capability of Buildings Conforming 

to Current Codes (RMP-14) 

As noted earlier, many decision-makers will determine that the optimal level 

of seismic performance for their particular building investment is the 

minimum permitted by regulatory authority. Regulatory authorities typically 

rely on the building code to establish “acceptable” levels of building 

performance, even though the expected performance is poorly defined. In 

some cases, decision-makers who desire the minimum legally accepted 

performance may still wish to have buildings designed using a performancebased approach to determine if it will permit more economical designs or 

designs using systems or approaches that are not specifically permitted by the 

codes. In order to do this, it is necessary to quantify the performance of 

buildings designed and constructed in conformance with current building 

code requirements so the minimum acceptable level is clearly understood. 

In Task RMP-14, the Risk Management Products Team will work with the 

Structural and Nonstructural Performance Products Teams to develop a series 

of representative case study buildings that represent typical structures 

designed and constructed in accordance with current code requirements and 

prevailing structural practices for various regions of seismicity and seismic 

use groups. The Risk Management Products Team will then evaluate the 

performance of these case-study buildings to define the performance 

provided by current code requirements. This will define the performance 
82 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

targets that will be used for the performance-based option of designing to 

minimum code criteria. This task will also allow a critical evaluation of the 

adequacy of current code provisions and design and construction practices, 

which will provide valuable information to the organizations responsible for 

development of building codes. 

6.3.6 Evaluate Performance Capability of Typical Existing 

Buildings (RMP-15) 

In past years, extensive work has been performed to identify types of existing 

buildings that pose an unacceptable risk to life. As a result of this past work, 

unreinforced masonry buildings, nonductile concrete frame buildings, tiltup 

building without adequate wall anchorage, and several other types of 

buildings have been identified as significant risks and building code 

requirements and ordinances for the upgrade of these structures have been 

developed adopted by some communities. 

In the western United States, many seismic upgrades of existing buildings 

have been performed for economic reasons rather than reasons of protecting 

life safety. Lenders have commonly required seismic performance 

evaluations of buildings and adjusted the terms of loan agreements based on 

the results of these seismic assessments. Many building owners have 

consequently invested in voluntary upgrades of buildings in order to obtain 

more favorable mortgage loans. The evaluations performed on behalf of 

lenders typically estimate building Probable Maximum Loss, a measure of 

the probable repair costs for a building. Although many Probable Maximum 

Loss studies have been conducted of buildings, these have all been conducted 

on behalf of private parties and are not in the public domain. As a result, 

other than a subjective study performed by the Applied Technology Council 

in the mid-1980s (ATC, 1985)—which does not directly apply to many types 

of buildings constructed in the past 20 years—there is no comprehensive 

basis on which to rate the likely economic losses associated with buildings of 

different types and eras of construction. 

In Task RMP-15, the Risk Management Products Team will develop Seismic 

Performance Assessments for a number of existing building types located in 

a variety of seismic environments. Data on the likely repair costs and 

occupancy interruption times will be obtained for different types of 

buildings. Task RMP-15 will provide data for the Stakeholder Guides on the 

approximate seismic risk associated with different types of existing 

buildings. Risks will be expressed in terms of life risk, repair cost risk, and 

occupancy interruption risk. This will enable decision-makers to develop 

rapid understanding of the probable level of risk associated with different 
FEMA 445 6: Phase 2: Developing Procedures and Guidelines—Product Tasks 83 

buildings and to determine if more detailed consideration of an existing 

building for a given use is appropriate. 

It is anticipated that this task will be performed by a number of consultants 

around the United States, working under the direction of the Risk 

Management Products Team. These consultants will be asked to select 

representative buildings in their region and to perform evaluations of these 

buildings. This data will be compiled into a database by the Risk 

Management Products Team. 

6.3.7 Develop Stakeholder Guides (RMP-16) 

The Stakeholder Guides will provide information to decision-makers they 

can use to make performance choices for buildings they develop or occupy, 

and assist them in making appropriate seismic performance choices when 

entering into building design or occupancy projects. Since there are many 

different types of decision-makers with different needs, interests, and levels 

of sophistication, a series of publications will be prepared, each with a 

different intended primary audience. On a preliminary basis, guidelines will 

be developed for the following decision-maker groups: 

• Building developers 

• Corporate risk managers 

• Mortgage lenders 

• Property casualty insurers 

• Institutional risk managers 

• Homeowners 

• Small business owners 

Publications will be tailored to the individual interests, decision processes, 

and levels of sophistication of the target stakeholder group. Focus groups of 

representative stakeholders in the individual areas will be asked to review the 

publications in draft form and provide input as to whether the publications 

have the appropriate focus and how useful they are. At least two preliminary 

drafts will receive outside review. Final development of the Stakeholder 

Guides will be tailored based upon this feedback. 

6.3.8 Provide Input to Design Guidelines (RMP-17) 

The primary goal of Task RMP-17 is to develop Performance-based Seismic 

Design guidelines that will help design professionals to efficiently develop 

designs that will be able to meet a broad range of performance objectives.. 

The Risk Management Products Team will be responsible for developing 
84 6: Phase 2: Developing Procedures and Guidelines—Product Tasks FEMA 445 

those portions of the Performance-based Design Guidelines that relate to the 

basic performance-based seismic design process, selection of appropriate 

performance objectives for buildings, communications with decision-makers 

and consideration of alternative strategies, and all other structural and 

nonstructural measures to mitigate losses. It is anticipated that much of the 

quantitative material contained in the Stakeholder Guides, developed under 

Task RMP-16, will be included in the Performance-based Design Guidelines, 

so that design professionals can work effectively with decision-makers and 

help them select appropriate performance goals for projects. 

The community of practicing engineering design professionals will provide 

significant input to of these documents, and opportunities will be provided 

for public input as well. During the second year of the Phase 2 Program 

Plan, this draft will be prepared for internal team coordination and planning 

only, and will not be released for public review. Second and third drafts of 

the publication will be prepared in the third and fourth years of Phase 2, and 

public review of these documents will be solicited. The final draft, prepared 

in the fifth year, will address the public review comments obtained in prior 

review cycles. 
FEMA 445 A: Seismic Performance Assessment 85 

Appendix A 

Seismic Performance 

Assessment

The next-generation performance-based seismic design guidelines will 

measure building performance in terms of the potential for casualties, 

repair/replacement costs and downtime resulting from earthquake-induced 

damage to a building. Section 2.5 of this report introduced the basic 

concepts behind expressing performance in this manner and the basic steps in 

the performance-based design and assessment process. This Appendix A 

provides a more detailed introduction to these concepts, which are still at a 

preliminary level of development. Its primary focus is on the framework for 

calculating probable future building performance and expressing this 

performance in a flexible format to suit various decision-makers. 

Appendices B and C present several approaches that have been developed on 

a preliminary basis, to implement these procedures. More detailed 

development of these approaches will be conducted under the project 

described in this Program Plan. 

A.1 Performance-Based Design Process 

Figure A-1 illustrates the basic performance-based design process, previously 

introduced in Section 1.3 and discussed in Section 2.5. 

The process begins with the selection of design criteria stated in the form of 

one or more performance objectives. Performance objectives are statements 

of the acceptable risk of incurring different levels of damage and the 

consequential losses that occur as a result of this damage. In the nextgeneration performance-based design procedures, performance objectives are 

statements of the acceptable risk of incurring casualties, direct economic loss 

(repair costs), and occupancy interruption time (downtime) associated with 

repair or replacement of damaged building elements. These performance 

objectives can be stated in three different ways: 

• Intensity-based objectives – statements of the acceptable casualties, 

repair/replacement costs and downtime in the event that the building is 

subjected to a specific intensity of ground shaking 

• Scenario-based objectives – statements of the acceptable casualties, 

repair/replacement costs and downtime if a specific earthquake event 

occurs, where the event is defined by a magnitude, fault, and possibly, 

rupture location and/or direction 
86 A: Seismic Performance Assessment FEMA 445 

• Time-based objectives – statements of the acceptable probability of 

incurring casualties, repair/replacement costs and downtime, over a 

defined period of time, considering all possible earthquake events that 

can occur and the probability of occurrence of each, within the defined 

time frame. 

Once design criteria in the form of performance objectives have been 

selected, the next step in the process is the development of a preliminary 

design. This includes selection of a site, specification of the building 

configuration and occupancy, selection of structural systems, and definition 

of the types and quality of various nonstructural components and systems 

and their locations throughout the structure. Phase 2 of this Program Plan 

addresses the action items necessary to develop guidelines to assist engineers 

in developing preliminary designs likely to meet desired performance 

objectives. 

Once performance objectives have been selected and a preliminary design 

developed, it becomes necessary to assess the performance capability of the 

design to determine if it meets the selected performance objectives. Detailed 

performance assessment procedures, and guidelines to assist design 

professionals with this process, will be developed in Phase 1 of this Program 

Plan. The following sections of this Appendix describe in some detail the 

basic concepts associated with the performance assessment process and some 

of the issues that need to be resolved during implementation of Phase 1 of 

this Program Plan. 

Figure A-1 Performance-based design flow diagram. 
FEMA 445 A: Seismic Performance Assessment 87 

A.2 Performance Assessment Process 

Figure A-2 illustrates the individual steps in the performance assessment 

process, as it will be implemented in the next-generation performance-based 

seismic design procedures. These steps include: 

• Characterization of the ground shaking hazard. 

• Analysis of the structure to determine its probable response and the 

intensity of shaking transmitted to supported nonstructural components 

as a function of ground shaking intensity. 

• Determination of the probable damage to the structure at various levels 

of response. 

• Determination of the probable damage to nonstructural components as a 

function of structural and nonstructural response. 

• Determination of the potential for casualty, capital and occupancy losses 

as a function of structural and nonstructural damage. 

• Computation of the expected future losses as a function of intensity, 

structural and nonstructural response, and related damage. 

These steps are discussed in the sections that follow. 

Characterize Ground

Shaking Hazard

Form

Structural

Damage Function

Predict Loss

as a Function of

Damage

Form

Structural Response

Function

Perform

Structural

Analysis

Form

Structural Fragility

Function

Perform

Analysis of

Nonstructural Systems

Form

Nonstructural

Response Functions

Form

Nonstructural

Fragility Functions

Form

Nonstructural

Damage Functions

Characterize Ground

Shaking Hazard

Form

Structural

Damage Function

Predict Loss

as a Function of

Damage

Form

Structural Response

Function

Perform

Structural

Analysis

Form

Structural Fragility

Function

Perform

Analysis of

Nonstructural Systems

Form

Nonstructural

Response Functions

Form

Nonstructural

Fragility Functions

Form

Nonstructural

Damage Functions

Figure A-2 Performance Assessment Process 
88 A: Seismic Performance Assessment FEMA 445 

A.3 Characterization of Ground Shaking Hazard 

The way that ground shaking is characterized in the performance assessment 

process is dependent on the type of performance objective, (i.e., intensitybased, scenario-based or time-based) that is being used. The simplest form 

of ground shaking characterization occurs when intensity-based performance 

objectives are used. In this case, it is only necessary to define a specific 

intensity of motion that the building will be designed to resist. 

The parameter used to describe ground motion intensity is termed an 

intensity measure. A number of different intensity measures have been used 

in the past, including Modified Mercalli Intensity (MMI), Rossi-Forrell 

Intensity, peak ground acceleration, and spectral response acceleration, 

among others. For more than 30 years, design procedures have used linear 

acceleration response spectra and parameters derived from these spectra as 

the basic intensity measures. Linear acceleration response spectra are useful 

and form the basis for both present national seismic hazard maps and 

building code procedures. However, there is presently a lack of consensus as 

to how to derive and scale ground motion records so that they appropriately 

match the intensity represented by a response spectrum. Further, most 

current procedures for ground motion record scaling produce significant 

variability in predicted response when nonlinear dynamic analyses are 

performed. An important task under Phase 1 of this Program Plan is to 

provide guidance on selection and scaling of records for purposes of analysis, 

so as to minimize the variability associated with response prediction. 

In order to assess the ability of a structure to meet a scenario-based or timebased performance objective, it is necessary not only to define a single 

intensity of motion, but rather, a range of motion and intensities, and the 

probability of occurrence of each. This information is typically presented in 

the form of a hazard function. The hazard function for a site is simply an 

expression of the probability that ground shaking of different intensities may 

be experienced at the site. The hazard function can be formed on a scenario 

basis (considering only the occurrence of a specific magnitude earthquake on 

a specific fault) or on a time-period basis (considering all potential 

earthquakes on all known faults and the probability of occurrence of each 

within a defined period). 

Figure A-3 is an example scenario-based hazard function for a hypothetical 

building site and earthquake scenario—for example, a magnitude-6.5 

earthquake on a fault that has a closest distance to the site of 20 kilometers. 

This function indicates, in the form of a log-log plot, the conditional 

probability that ground shaking with a peak ground acceleration exceeding 
FEMA 445 A: Seismic Performance Assessment 89 

various levels will be experienced at the site, given that this scenario 

earthquake occurs. Figure A-4 presents this same hazard function, plotted in 

a Cartesian rather than logarithmic scale. 

Figure A-3 Scenario-based hazard function for hypothetical building site 

and earthquake scenario. 

Figure A-4 Scenario-based hazard function for site using Cartesian 

coordinates. 

As can be seen, this hazard function indicates a 50 percent chance that the 

peak ground acceleration produced at this site from the scenario earthquake 

will have a value in excess of 20 percent g, a 25 percent chance that it will 

have a value in excess of 40 percent g, and approximately a 5 percent chance 

that it will have a value in excess of 60 percent g. Such uncertainty as to the 

actual value of ground shaking intensity that will occur at a site given that a 

scenario earthquake occurs is a result of a number of factors, described 

below. 
90 A: Seismic Performance Assessment FEMA 445 

Hazard functions are most commonly generated using attenuation equations. 

Attenuation equations are empirically derived functions that relate various 

ground motion intensity measures, such as peak ground acceleration, to 

parameters that are descriptive of the earthquake and site, including the 

magnitude of the earthquake, the type of fault mechanism, the distance from 

the rupture surface to the site, the type of soil conditions present at the site, 

the direction in which the fault rupture propagates, and other factors. The 

attenuation equations are developed by performing regression analyses of 

actual strong ground motion recordings against these various parameters. 

While the engineering parameters have significant correlation with the 

recorded data, they do not correlate perfectly, resulting in scatter of the actual 

data on ground shaking intensity relative to the values predicted by the 

equations. For example, the 2004 Parkfield California earthquake occurred 

in an area of dense instrumentation, and demonstrated that earthquakes can 

have a surprising variability in ground motion intensity over short distances. 

Additional variability is introduced by the random nature of earthquake 

occurrence: a fault may rupture at any point along the fault; and it may either 

rupture towards or away from the site. Still more variability is introduced by 

a lack of precise knowledge about the site soil conditions, the presence of 

sedimentary basins that could cause reflection of the earthquake waves, or 

the response characteristics of hilly terrain, all of which can affect shaking 

intensity. 

When time-based performance objectives are used, ground shaking intensity 

is represented by hazard functions that are developed considering all 

potential earthquake scenarios, and the probability of occurrence of each 

scenario within a given period of time. Time-based hazard functions appear 

similar to scenario-based hazard functions and are used in the same way. 

However, rather than indicating the conditional probability of experiencing 

different levels of shaking intensity given that a specific scenario earthquake 

occurs, probabilistic hazard functions indicate the total probability of 

exceeding different shaking intensity levels at a site over a defined period of 

time. Hazard function may express the probability in the form of an annual 

probability of exceedance (or nonexceedance), an average return period, or 

the probability of exceedance (or nonexceedance) in a defined period of 

years, usually taken as 50. It can be expressed as a mean probability, in 

which the uncertainty associated with the function is averaged, or confidence 

bounds associated with the uncertainties can be expressly indicated. 
FEMA 445 A: Seismic Performance Assessment 91 

A.4 Structural Analysis and Structural Response 

Functions 

Structural analysis serves two basic functions in the performance assessment 

process: 

• Prediction of structural response quantities, including member forces, 

deformations, and interstory drifts that can be used as predictors of the 

damage sustained by the structure. These response quantities are termed 

engineering demand parameters, or demands. 

• Prediction of the intensity of demands on nonstructural elements and 

systems supported by and suspended from the structure. These demands 

include interstory drifts, floor accelerations, and velocities and are 

termed nonstructural engineering demand parameters, or nonstructural 

demands. 

The first use of structural analysis is to predict structural damage. For a 

given structure and a given level of ground motion intensity, structural 

analysis is performed to predict the value of one or more demands. In a later 

step of the performance assessment process, these parameters will be used to 

predict damage. In order to illustrate this process, we consider the case of a 

hypothetical, three-story, moment-resisting steel frame structure located on 

an arbitrary site. 

As previously discussed, in order to assess the performance of this 

hypothetical structure, or any structure, ground motion intensity must be 

quantified with the use of an intensity measure. For the purpose of this 

illustration, the 5 percent-damped, elastic spectral response acceleration at 

the fundamental period of the structure is selected as the intensity measure. 

Interstory drift is selected as the demand used to predict damage. A ground 

motion record that is representative of the character of shaking likely to be 

experienced at the site is selected and appropriately scaled so that it 

corresponds to a particular value of the 5 percent-damped spectral response 

acceleration. Next, a nonlinear dynamic analysis of the structure is 

performed using this scaled record and the peak value of the interstory drift 

at each level is determined. 

The value of interstory drift predicted by the analysis depends on several 

factors, including the distribution and magnitude assumed for the structure’s 

mass, the stiffness, strength, damping, and hysteretic characteristics used to 

model the structure as well as the specifics of the ground motion record. If a 

different ground motion record is selected for the analysis and is 

appropriately scaled to the intensity measure, and all of the other modeling 

parameters are left unchanged, a different value for the interstory drift will 
92 A: Seismic Performance Assessment FEMA 445 

likely be predicted. In general, if this process is repeated using a number of 

different ground motion records, all scaled to the same value of the intensity 

measure, each will result in somewhat different predictions of peak interstory 

drift. If a large number of these ground motion records are used in the 

analysis and each is equally representative of the intensity measure and the 

hazard for the site, then the results of these various analyses will define a 

random distribution of interstory drift demands that can result from this 

particular ground motion intensity level. Figure A-5 is a probability density 

function representing such a distribution. 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00%

Interstory Drift Ratio - %

Probabiltiy 

Median

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00%

Interstory Drift Ratio - %

Probabiltiy 

Median

The information presented in Figure A-5, can also be represented in the form 

of a cumulative probability function, which indicates the probability that 

interstory drift will be less than or equal to a given value. Figure A-6 

presents this same data shown in Figure A-5 as a cumulative probability 

function. 

For the particular distribution illustrated in Figures A-5 and A-6, the median 

value is an interstory drift of 1.5%. That is, there is a 50% chance that the 

interstory drift resulting from any ground motion for this site corresponding 

to this intensity level will produce a drift less than 1.5%. The distribution is 

somewhat skewed, as is typical of such distributions. The average (mean) 

value is an interstory drift of about 1.6%. There is a 10% probability that 

interstory drift resulting from ground motions at this intensity level will be 

less than 1% and a 90% chance it will be less than 2.3%. 

Figure A-5 Probability distribution for structural response, expressed as interstory drift 

ratio for a particular structure and ground shaking intensity. 
FEMA 445 A: Seismic Performance Assessment 93 

Figure A-6 Cumulative probability distribution for structural response expressed as 

interstory drift ratio for a particular structure and ground shaking intensity. 

If similar analyses are performed for a range of ground motion intensities, it 

is possible to develop a structural response function that indicates the 

probable distribution of the demand, in this case interstory drift, for different 

levels of ground motion intensity. Figure A-7 illustrates a structural response 

function of this type, indicating the probable range of interstory drift for 

different levels of first mode elastic spectral response acceleration for a 

hypothetical structure. The figure shows the median prediction of interstory 

drift demand as well as interstory drift demands at 10% and 90% 

probabilities of exceedance, for various spectral function, similar to that of 

Figure A-5, that fits these data. In Figure A-7, 

Figure A-7 Hypothetical structural response function for building. 
94 A: Seismic Performance Assessment FEMA 445 

such a probability density function is overlaid on the response function at a 

acceleration values. As illustrated in the figure, at any spectral response 

acceleration level, Sa, it is possible to superimpose a probability density value 

of first mode spectral response acceleration of 1g. It can be seen that the 

median value of the predicted demand is an interstory drift ratio of about 5%, 

the 90% probability of exceedance interstory drift ratio is about 3.8%, and, 

the 10% probability of exceedance interstory drift is about 6.4%. It can also 

be seen that the amount of variability in potential response is negligible at 

low ground motion intensity levels, where structural response is linear and 

increases rapidly as ground motion intensity increases and response becomes 

nonlinear. 

The structural response function illustrated in Figure A-7 was developed with 

the stiffness, mass, damping, and hysteretic parameters for the structure held 

invariant, as if the true value of these parameters was precisely known. 

While most probable values for these parameters can be estimated with 

ranges of potential variation, the true values are seldom, if ever, known, and 

there is some uncertainty as to what the precise values are. To the extent that 

the values for the parameters used in the analyses are inaccurate, the resulting 

structural response function for the building may either over- or underpredict the probable response level at a given ground motion intensity level. 

If an additional series of analyses of the structure are performed, varying the 

assumed values for the uncertain structural parameters—including mass, 

stiffness, strength and damping—within their likely limits, it would be 

possible to predict the additional variation in probable interstory drift 

demand introduced by these uncertainties. The effect of these uncertainties 

will be to broaden somewhat the scatter associated with the response function 

and produce some non-negligible variation in predicted response even at low 

levels of ground motion intensity, where the structural response is linear. 

For a real structure, the task of defining the response function, considering 

these uncertainty bounds, can be a complex and time-consuming process 

requiring many analyses. As an alternative, it is possible to estimate the 

additional scatter introduced by the uncertainties by assuming that the 

variability can be represented by a standard distribution shape, typically lognormal, and by selecting a coefficient of variation based on either expert 

judgment or the variability observed in analysis of a limited number of 

standard structures. The development of efficient and practical methods of 

developing such response functions for routine use on engineering projects 

will be an important part of Phase 1 of this Program Plan. 
FEMA 445 A: Seismic Performance Assessment 95 

The second purpose of structural analysis is to predict the probable intensity 

of shaking that will be experienced by nonstructural components and systems 

mounted at different levels in the structure. These data will typically be 

developed and represented in a form similar to the response function 

illustrated in Figure A-7, except that in addition to interstory drift, other 

parameters that are useful to the prediction of nonstructural component 

response (such as in-structure response acceleration at a particular 

nonstructural component period) will also be used. 

A.5 Formation of Nonstructural Response Functions 

If a nonstructural component is infinitely rigid, the shaking imparted to the 

component by the structure, expressed in the form of peak interstory 

displacement or floor acceleration, can be used directly to predict the 

behavior of the component. However, nonstructural components with finite 

rigidity will have their own dynamic response to the motions imparted to 

them by the structure. For such components, it may be necessary to perform 

a structural analysis of the component to predict its response to the shaking 

imparted to it (in the form of nonstructural demands, such as acceleration or 

displacement of the component itself), which can then used to assess the 

level of damage incurred. 

Figure A-8 is illustrative of a nonstructural component demand function that 

could be used to predict the response of a flexible component having a period 

of 0.5 second that is sensitive to acceleration. In Figure A-8, in-structure 

response acceleration at a period of 0.5 second, that is, the 

0%

50%

100%

150%

200%

250%

300%

0% 20% 40% 60% 80% 100%

Peak Ground Accel. -%g

0.5 Sec. In-structure 

Response Accel. - %g

Median 90% Prob. Exc. 10% Prob. Exc.

Figure A-8 Illustrative nonstructural component demand function for floor 

response acceleration at 0.5 second. 
96 A: Seismic Performance Assessment FEMA 445 

acceleration experienced by a component having a natural period of vibration 

of 0.5second, mounted at a particular level in the structure, is plotted as a 

function of ground motion intensity, here represented by peak ground 

acceleration. As with the structural response function of Figure A-7, 

uncertainty and confidence bands are an integral part of such a plot. 

In order to be useful in the performance assessment process for nonstructural 

components, it is necessary to convolve the data in the demand function with 

the ground shaking hazard function for the site. This process yields a hazard 

function that indicates the probability of experiencing a given intensity of instructure shaking at a particular floor or roof level. Figure A-9 illustrates 

such an in-structure shaking intensity function, which has been constructed 

by convolving the demand function of Figure A-8 with the hazard function of 

Figure A-3. The resulting in-structure shaking hazard function of Figure A-9 

could be used to predict the response of nonstructural components with a 

fundamental period of 0.5 second mounted at the particular level of the 

hypothetical building used in this example. A family of such curves for 

different nonstructural component periods could then be used to develop 

response functions for various nonstructural components, in the same way 

response functions were developed for the structure itself. 

0.01

0.1

1

0% 50% 100% 150% 200%

0.5 Second Floor Response Acceleration - %g

Conditional Probability of 

Exceedance

Figure A-9 Illustrative nonstructural component response acceleration 

hazard curve. 

A.6 Evaluation of Structural Fragilities 

Structural fragilities are functions that indicate the probability that a 

structural component or system will experience damage greater (or less) than 

a certain level, given that the component or system experiences a certain 

level of response, as measured by the demand. As is the case with response 
FEMA 445 A: Seismic Performance Assessment 97 

functions, fragilities are expressed as probability distributions, rather than 

deterministic relationships in order to account for the variability and 

uncertainty inherent in the process of predicting structural damage as a 

function of structural response. 

The variability is associated with such factors as the random nature of 

structural response to individual ground motion records and the inability of 

simple demand parameter to distinguish between this response variation and 

the damage it causes. For example, two different ground motions may each 

produce peak interstory drift demands of 4 inches in a structure. However, 

one of these ground motions may cycle the structure to this drift level one 

time, then restore the structure to small oscillations about its original 

position; while the second ground motion may cycle the structure to this drift 

level several times and leave the structure displaced nearly to this level. 

Clearly the second motion will be more damaging to the structure than the 

first motion, though the value of the demand is the same. Such effects are 

not predictable unless the precise ground motion and structural response is 

known, which will never be the case. Uncertainty is introduced through such 

factors as lack of precise definition of material strength and construction 

quality. 

In order to form fragility functions, it is first necessary to establish measures 

of damage. A variety of such measures are possible. Early research in this 

area used the concept of damage indices as measures of damage to structural 

elements and systems. Damage indices are non-dimensional parameters, 

typically having values in the range of 0 to 1 where a value of 0 would 

indicate no damage and a value of 1 would indicate total damage. Most such 

damage indices have been developed on an element or component basis, but 

a few have been calculated on a global structural level. Generally, these 

damage indices are specific to a particular type of structural component or 

structural system. Most are of the form: 

≤ 1.0 ⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

+ ⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

Δ

Δ =

y

u

i

x

u

i

E

E

DI (A-1) 

where the quantity (Δi/Δu) is the ratio of the maximum inelastic displacement 

or deformation demand induced in the structure (or component) by the 

ground shaking to the ultimate static displacement capacity of the structure; 

and the quantity (Ei/Eu) is a measure of cumulative damage resulting from 

repeated cycles of inelastic response and has most commonly been expressed 

in the past as a ratio of inelastic energy dissipation demand to capacity. 

These damage indices have not been widely used for several reasons, 

including: 
98 A: Seismic Performance Assessment FEMA 445 

• They require the use of nonlinear response history analysis, a complex 

analysis procedure not widely used in practice. 

• The energy component is typically a small part of the computed index, 

making the complexity introduced by the second term seem unjustified. 

• There is little research available to suggest appropriate values of the Eu

term. 

• Engineers have little intuitive feel for damage indices and have difficulty 

relating them to an understanding of a structure’s actual performance. 

A second method for assigning damage parameters used in the past was to 

assign a series of discrete damage states or ranges, representing progressively 

more severe states of damage. This is the approach taken both by presentgeneration performance-based design methodologies, such as FEMA 356, 

and also by loss estimation methodologies such as HAZUS. In FEMA 356,

these damage states are termed the Operational, Immediate Occupancy, Life 

Safety, and Collapse Prevention performance levels, with Operational 

representing a state of negligible damage and Collapse Prevention a state of 

near-complete damage. The HAZUS methodology uses damage states 

termed Slight, Moderate, Severe, and Complete, assigned based on the 

analyst’s understanding of the extent of damage to the structure as predicted 

by analysis. It should be possible for particular structural systems to develop 

relationships between either the FEMA 356 performance levels or HAZUS 

damage states and computed damage indices. However, it is not clear that 

either the damage indices, or the standard performance levels of the firstgeneration procedures, can be used efficiently to predict repair costs, time out 

of service, or potential life loss. 

A third potential method of parameterizing damage consists of a direct 

tracking of the condition of individual structural elements and components, 

on a piece-by-piece basis, coupled with measures of building-wide damage. 

For example, for moment-resisting steel frames, damage measures that could 

be used on a connection-by-connection basis include: panel zone yielding, 

beam plastic hinging, beam flange buckling, and welded joint fracturing. 

Measures of building-wide damage could include tracking of residual 

interstory drifts of different amounts on a story-by-story basis (e.g., 1 

percent, 2 percent, 3 percent, etc. up to collapse). Each of these damage 

states would have different implications with regard to occupant safety 

during the earthquake, post-earthquake safety, repair effort and cost, and 

occupancy interruption. The consequences of each of these individual 

damage measures must be aggregated on a system basis, over the entire 

structure. 
FEMA 445 A: Seismic Performance Assessment 99 

Structural fragilities may be formed on either a structure-specific or structural 

system-specific basis. Absent a practical ability to build prototype structures, 

test them, and measure the amounts of damage that have occurred, fragilities 

must be formed on the basis of simulation or analysis, laboratory data on 

component performance, and expert judgment. As an example, fragilities 

have been constructed on a preliminary basis for moment-resisting steel 

frames based on data obtained from the FEMA/SAC program completed 

several years ago. For the purpose of this example, fragilities have been 

developed for the case of a regular, low-rise special moment resisting steel 

frame building employing reduced beam section detailing. Local damage 

measures relating to the condition of individual structural components are 

taken as initiation of beam yielding, initiation of beam flange buckling, and 

beam flange fracture. Building-wide damage measures, relating to the 

condition of the overall structure are taken as permanent interstory drifts of 1 

percent, 2 percent, 3 percent and story collapse. 

Following recommendations from the FEMA/SAC project, a single demand, 

peak interstory drift ratio, is used as an index for each of these damage 

measures. Based on the FEMA/SAC study, median values of interstory drift 

demand at which beam flange yielding initiates is taken as 0.01 radians; at 

which beam flange buckling initiates as 0.02 radians; and at which beam 

flange fracture initiates as 0.06 radians. A best “estimate” of permanent 

interstory drift is 50 percent of peak interstory drift, and a best estimate of the 

interstory drift at which collapse initiates is 0.1 radians. Coefficients of 

variation associated with each of these behaviors are estimated at 0.1 for 

initiation of yielding, 0.2 for initiation of buckling, 0.3 for initiation of flange 

fractures and permanent interstory drift, and 0.5 for initiation of collapse. 

Figure A-10 shows a plot of fragilities for these several damage states for 

individual beam-column connections. Figure A-11 shows a plot of fragilities 

for global measures of damage for this structural system computed using the 

above data and assumptions. In order to construct these fragilities, it has 

been assumed that the distribution of failure capacities is log-normally 

distributed using the median values and variances described in the previous 

paragraphs. 

The fragility curves illustrated in Figures A-10 and A-11 indicate the 

probability that damage will be equal to or greater than that corresponding to 

each of the several damage states. To determine the probability that a 

structure will experience damage within a given state at a given level of 

response, it is necessary to take the difference between the probability that it 

initiates damage within the given state and the probability that the structure 

will initiate damage in the next most severe state. For example, for the 
100 A: Seismic Performance Assessment FEMA 445 

fragility curves plotted in Figure A-10, at an interstory drift demand of 3 

percent, there is essentially a 100 percent chance that beam flanges will have 

yielded, approximately a 95 percent chance that buckling damage will initiate 

in flanges, and approximately a 5 percent chance that damage will include 

fracturing of the beam flanges or welded connections. For this case, the 

probability that beam flanges will have yielded but not buckled will be the 

probability of yielding (100 percent) minus the probability of buckling (95 

percent), or 5 percent. The probability of buckling but not fracturing will be 

the probability of buckling (95 percent) minus the probability of fracturing (5 

percent), or 90 percent. 

Figure A-10 Example fragility function for beam-column connection behavior. 

Figure A-11 Example fragility function for building-wide structural behavior. 
FEMA 445 A: Seismic Performance Assessment 101 

Similarly, at a peak interstory drift demand of 3%, there is a 96% probability 

that the structure will sustain a permanent interstory drift of 1% or greater, an 

18% chance the structure will sustain an interstory drift of 2% or greater, 

approximately a 5% chance of a permanent interstory drift of 3% or greater, 

and about a 3% chance of collapse. 

A.7 Development of Nonstructural Fragilities 

Nonstructural fragilities serve the same purpose as structural fragilities, 

except that they indicate the probability that nonstructural components or 

systems, rather than structural components or systems, will be at or in excess 

of given damage levels. For rigid components, the fragility can be 

formulated as a direct function of a structural demand, such as interstory drift 

or peak floor acceleration. For flexible components, the fragility will be a 

function of the response of the nonstructural component, as measured by 

nonstructural demands obtained from structural analysis of the nonstructural 

component. Damage states that may be meaningful for nonstructural 

components and systems could include loss of function, loss of leaktightness, loss of structural integrity, and toppling, as well as others. In 

general, each class of nonstructural component or system, such as suspended 

ceilings, fire sprinkler systems, interior partitions etc., will have different 

fragility functions, which will be tied to several different damage states and 

intensity measures. These can be determined through collection of 

earthquake performance data on damage sustained by actual installations, 

through laboratory testing programs, and in some cases, through structural 

analysis, just as would be done for the building structure itself. 

Figure A-12 is a hypothetical fragility curve for a single drift-sensitive 

nonstructural component (exterior curtain walls). This fragility curve shows 

the probability of experiencing various damage states including: breakage of 

glass, fallout of glass, and failure of panel connections as a function of 

structural interstory drift. The fragilities shown in Figure A-12 are 

illustrative only and are not representative of real data. 

In addition to fragility functions for nonstructural components, it is also 

necessary to develop fragility functions for nonstructural systems such as fire 

sprinklers, building lighting, HVAC systems, manufacturing systems, data 

processing systems, etc. In order to develop fragility functions for such 

systems, it is necessary to consider the inter-relationships between the 

components that comprise the system and understand how failures of 

individual components and combinations of components affect system 

performance. Typically, it will be necessary to construct logic trees to 

identify the effect of the failure of single components and combinations of 
102 A: Seismic Performance Assessment FEMA 445 

components on system operability and function. Then, at various levels of 

intensity, the failure probability for the individual components, for 

combinations of components, and for the system itself can be calculated, 

allowing a system fragility to be developed. 

Figure A-12 Hypothetical fragility curve for exterior cladding. 

A.8 Evaluation of Structural and Nonstructural Loss 

Functions 

Loss functions indicate the probability of incurring various levels of loss, 

given that a structural or nonstructural component or system is damaged to a 

given level. Loss functions are expressed in parameters such as casualties, 

direct economic loss (repair costs), and/or hours of lost service or occupancy 

(downtime). Loss functions can be constructed for a given building or class 

of buildings by postulating damage to the structure (or nonstructural 

component/system) that is representative of a damage level for which there is 

an available fragility function, and estimating the losses associated with this 

damage. By varying the assumptions, or exploring the level of uncertainty 

associated with the assumptions inherent in these estimates, it is possible to 

determine probability distributions of the possible losses, as a function of the 

damage states. Alternatively, it may be possible to construct loss functions 

directly from historical earthquake data, if available. 

Loss functions tend to incorporate significant uncertainty as compared with 

hazard, response, and fragility functions. This is because they are highly 

dependent on human factors. These include the owner’s ability to act rapidly 

in retaining the necessary design professionals and construction contractors 

to effect repairs, the efficiency with which the design professionals and 

contractors operate, the speed with which city and/or county building 
FEMA 445 A: Seismic Performance Assessment 103 

departments approve proposed repair programs, and the willingness of 

people to occupy the building during repair—among other factors. 

Figure A-13 is a hypothetical loss curve that indicates the probable repair 

cost for a single beam-column connection in a moment-resisting steel frame 

structure if the connection is damaged to any of the levels indicated in Figure 

A-10—that is, beam flange yielding, beam flange buckling, or beam flange 

fracturing. For example, Figure A-13 shows that if a connection is damaged 

to an extent that the welded beam flange to column flange fractures, there is 

roughly a 20% chance that repair cost will be $1,400 or less, a 50% chance 

the repair cost will be $5,000 or less, and an 80% chance the repair cost will 

be $17,000 or less. This variability in the potential repair cost is a result of 

such factors as the type of ceiling present, the amount of ductwork and other 

utilities that restrict access to the damaged framing, the type of fire-resistive 

materials present, and the efficiency of the contractor in making repairs. 

Figure A-13 Hypothetical loss curve for repair cost of damaged beam-column connections. 

The data in Figure A-13 are based on the estimated cost of repairing 

moment-resisting steel frames developed during the FEMA/SAC program. 

Figure A-14 is a hypothetical loss curve for fatalities in an office building, 

given that a story collapse occurs. It shows a 20% chance of 0.2 or fewer 

fatalities per 1,000 square feet of floor area in the story, a 50% chance of 0.5 

or fewer fatalities per 1,000 square feet of floor area and roughly an 80% 

chance of one or fewer fatalities per 1,000 square feet of floor area. This 

variability may be attributed to the fact that the number of people present in a 

building varies with the time of day and day of the week and also that 

collapse of a story can be either partial or total. Obviously, loss curves of 

this type are highly dependent on the type of building occupancy. 
104 A: Seismic Performance Assessment FEMA 445 

Figure A-14 Hypothetical loss curve for fatalities, given collapse. 

Loss curves (not shown here) for various nonstructural components and 

systems could be developed in a manner similar to those indicated in Figures 

A-13 and A-14. 

A.9 Predicting Loss as a Function of Damage 

Given the hazard functions for appropriate intensity measures, response 

curves for the structure and flexible nonstructural components, fragility 

curves for the structure and its nonstructural components, and loss curves for 

each of these, it becomes possible to characterize building performance, and 

thereby, building performance objectives, in a number of different ways. 

Many stakeholders will wish to deal with performance and risk information 

on a scenario basis. For example, they may wish to know how much loss 

they can expect, given that a certain magnitude earthquake occurs. Within 

this group of stakeholders/decision-makers, some may wish to know this 

information on an upper bound or “probable maximum” basis, while others 

will want to know a “best estimate” of the probable losses, given the 

scenario. Still others may wish to know the probability in a single year or 

number of years that losses of a given size will be experienced. Each of 

these, and other means of expressing loss, can be derived with the use of the 

hazard, response, fragility, and loss functions. Appendices B and C present 

an example application illustrating two different potential methods of 

illustrating these procedures to derive such performance assessments. 
FEMA 445 B: Example Application of Seismic Performance Assessment 105 

Appendix B 

Example Application of 

Seismic Performance Assessment 

Using Numerical Integration 

Techniques

This Appendix illustrates the application of the performance assessment 

process described in Appendix A. This application estimates potential future 

losses for a scenario earthquake for a hypothetical building. Note that for 

this simple illustrative example, nonstructural fragilities and losses are 

neglected. However, in practice, they could be and should be treated in an 

identical manner as the structural fragilities and losses illustrated here. In 

this illustrative example, a process of numerical integration is used to 

calculate expected losses as the probability of response (engineering demand 

parameter) given a level of shaking intensity (intensity measure), the 

probability of damage given response and the probability of loss given 

damage, summed over all possible intensity levels, considering the 

probability of each intensity level. If the various intensity, response, damage 

and loss functions are represented as mathematical expressions, such as 

lognormal distributions with defined median value and variance, it is possible 

to derive a closed-form solution for these various integrations that can the be 

used to calculate probable losses directly. Appendix C presents an example 

illustration of the closed-form approach to solution. 

It is also possible, although not illustrated by example in this report, to 

calculate the probable performance of a building using Monte Carlo solution 

techniques. In this approach, a large number of simulations are performed, 

varying assumptions as to ground motion, structural properties, damage, and 

loss, consistent with the hazard, response, fragility and loss function 

probabilities previously discussed and calculating expected loss in each case. 

This results in a statistical distribution for the expected loss at varying 

intensity levels. The advantage of the Monte Carlo solution technique is that 

it permits a confidence level, other than the mean, to be directly associated 

with the performance assessment. It does, however, require a large number 

of computations. Any of these approaches, or perhaps combinations of these 

approaches, can be incorporated into the next generation performance-based 

assessment and design guidelines. 
106 B: Example Application of Seismic Performance Assessment FEMA 445 

In this example, the mean scenario repair cost is calculated for a momentresisting steel frame building, for a scenario event having a 10% chance of 

exceedance in 50 years, or an annual probability of exceedance of 0.0021. 

The building is a three-story structure with a floor plate that is 140 foot long 

on each side, having bays that are 28 feet square and three, contiguous 

moment-resisting frames on each side of the structure. Thus, there are 

19,600 square feet per floor level, 58,800 square feet total in the building and 

108 individual beam-column connections in the structure. For the purposes 

of this example, it has been assumed that the response is identical in each 

direction and in each of the three stories and thus the probability of being 

damaged to the various states is the same for each story and in each principal 

direction of the building. 

Figure B-1, is the hazard curve for the site of the hypothetical building. It 

indicates the annual probability of exceeding various levels of ground 

shaking intensity, expressed in terms of peak ground acceleration. Three 

curves are shown on the figure representing median values, values with a 

10% confidence level (i.e., 90% chance of being exceeded) and values with 

a 90% confidence level (i.e. 10% chance of being exceeded), reflecting the 

aleatory uncertainty (randomness) associated with prediction of the 

probability of experiencing ground motion of different intensities. This 

figure expresses ground shaking intensity in terms of peak ground 

acceleration however other intensity measures, such as first mode elastic 

spectral response acceleration could also have been used. 

In Figure B-1, a horizontal line is drawn across the hazard curve at an annual 

probability of exceedance of 0.0021, representing the scenario event. Where 

this horizontal line intersects the 10% confidence level curve, one can read 

that there is less than a 10% chance that the peak ground acceleration 

resulting from an event with a 10% chance of exceedance in 50 years would 

be less than 0.22g. At the median curve, one can read that there is a 50% 

chance that the ground motion resulting from an event with a 10% chance of 

exceedance in 50 years would produce a peak ground acceleration of 0.42g 

or less. At the 90% confidence level, one can read that there is a 90% chance 

that the scenario event with a 10% chance of exceedance in 50 years would 

produce ground motion with a peak ground acceleration less than or equal to 

0.80g. By interpolation, it is possible to estimate the peak ground 

acceleration associated with any confidence level for this 10%-50 year 

scenario event. Table B-1 is such a tabulation of these peak ground 

accelerations at confidence intervals of 5%. 
FEMA 445 B: Example Application of Seismic Performance Assessment 107 

Figure B-1 Hazard Curve with intensity at 10% chance of exceedance in 50 

years indicated 

Table B-1 Peak Ground Acceleration for 10%/50 Year Event, at Various 

Confidence Levels 

Confidence 

Level1

pga - g Confidence 

Level1

pga – g Confidence 

Level1

pga – g 

5% 0.18 40% 0.37 75% 0.59 

10% 0.22 45% 0.40 80% 0.65 

15% 0.25 50% 0.42 85% 0.71 

20% 0.28 55% 0.45 90% 0.80 

25% 0.30 60% 0.48 95% 0.96 

30% 0.33 65% 0.51 

35% 0.35 70% 0.55 

1

Confidence level is an expression of uncertainty with regard to the true value of a random 

variable. The confidence level represents the probability that the true value is less than or equal 

to the stated value. 

Figure B-2 is a response curve for the hypothetical structure, indicating the 

probability of experiencing various levels of interstory drift as a function of 

the peak ground acceleration experienced by the structure. This response 

curve is derived by performing structural analyses for a number of ground 

motions and ground motion intensity levels, as described in Appendix A. 
108 B: Example Application of Seismic Performance Assessment FEMA 445 

Entering Figure B-2 at a specific peak ground acceleration it is possible to 

determine the likelihood of experiencing a given level of interstory drift. For 

example, at a peak ground acceleration of 0.8g, there is a 10% confidence 

that interstory drift will be 3.5 inches or less, a 50% confidence that it will be 

less than or equal to 4.8 inches and a 90% confidence that it will not exceed 

6.7 inches. 

Figure B-2 Response curve for hypothetical structure 

Table B-1 described above shows at varying levels of confidence, the level of 

peak ground acceleration expected for the scenario event being analyzed. 

Table B-2 presents this same data in a somewhat different format. In Table 

B-2 a series of confidence bands, each 10% wide are defined. For each 10% 

confidence band, a central value of the confidence and the central value of 

the pga is indicated. In order to perform the integration to determine 

probable loss, it can be said that each of the pga values indicated in the third 

column of Table B-2 has a 10% chance of occurrence, given that the scenario 

earthquake event occurs. 

For each of the pga values indicated in Table B-2, it is possible to enter 

Figure B-2 and determine the probability that the hypothetical structure will 

be excited to various levels of peak interstory drift. This exercise has been 

done, and is shown in Table B-3, which indicates the distribution of drift 

response for ground shaking having a 10% chance of exceedance in 50 years, 

considering uncertainty in both intensity and structural response. 

0

2

4

6

8

10

12

14

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Peak Ground Acceleration - g

Interstory Drift - %

Median 10% Conf. Level 90% Conf. Level
FEMA 445 B: Example Application of Seismic Performance Assessment 109 

Table B-2 Central Value of PGA for Scenario Event within 

Confidence Bands 

Confidence Range 

Mid Range Value 

of Confidence 

Mid Range Value of 

PGA - g 

0-10% 5% 0.18 

10%-20% 15% 0.258 

20%-30% 25% 0.30 

30%-40% 35% 0.35 

40%-50% 45% 0.40 

50%-60% 55% 0.45 

60%-70% 65% 0.51 

70%-80% 75% 0.59 

80%-90% 85% 0.71 

90%-100% 95% 0.96 

Table B-3 Distribution of Interstory Drift for the 10%/50 – Year Event 

Col 1 Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 Col 10 Col 11 Col 12 Col 13 

Confidence Drift Demand at Indicated Confidence Level in Hazard and Response

Interval for pga

Median 

pga g

Median 

drift - in

0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-70% 70-80% 80-90% 90-100%

0%-10% 0.19 0.93 0.64 0.73 0.80 0.85 0.90 0.96 1.02 1.09 1.18 1.36 

10%-20% 0.25 1.26 0.86 0.99 1.08 1.15 1.23 1.30 1.38 1.47 1.60 1.84 

20%-30% 0.30 1.51 1.04 1.19 1.29 1.38 1.47 1.56 1.65 1.77 1.92 2.21 

30%-40% 0.35 1.75 1.20 1.38 1.50 1.60 1.70 1.80 1.91 2.04 2.22 2.55 

40%-50% 0.40 1.99 1.36 1.57 1.70 1.82 1.93 2.05 2.17 2.32 2.53 2.90 

50%-60% 0.45 2.26 1.55 1.78 1.93 2.06 2.19 2.32 2.47 2.63 2.86 3.29 

60%-70% 0.51 2.57 1.76 2.02 2.20 2.35 2.50 2.64 2.81 3.00 3.26 3.75 

70%-80% 0.59 2.97 2.03 2.34 2.54 2.72 2.88 3.06 3.24 3.47 3.77 4.33 

80%-90% 0.71 3.91 2.68 3.08 3.35 3.58 3.80 4.03 4.28 4.57 4.97 5.71 

90%-100% 0.96 6.79 4.65 5.35 5.81 6.21 6.59 6.99 7.42 7.93 8.62 9.91 

Each row in Table B-3 represents a 10% confidence interval with regard to 

evaluation of intensity (peak ground acceleration). Columns 1 and 3 are 

identical to the entries in Table B-2, Columns 1 and 2. Column 3 of Table B3 tabulates the median estimate of drift response, from the response functions 

illustrated in Figure B-2, evaluated at each of the mid-range ground motion 

intensities indicated in column 2. Columns 4 through 13 indicate the midrange values of the interstory drift response evaluated for 10 different 

response confidence intervals. These are calculated using the median values 

of column 3 and coefficients of variation obtained from structural analyses of 
110 B: Example Application of Seismic Performance Assessment FEMA 445 

the hypothetical structure, assuming a lognormal distribution for drift 

response. Since there are 10 confidence intervals with regard to evaluation 

of intensity (rows) and 10 confidence intervals with regard to evaluation of 

response (columns) each entry in columns 4 through 13 has a 1% chance of 

occurrence, given that the scenario 10%/50-year ground shaking event is 

experienced. 

The data contained in columns 4 through 13 of Table B-3 can be presented 

more simply by doing a frequency analysis of the data and representing it in 

the form of a cumulative distribution function that indicates the conditional 

probability of nonexceedance of drift responses at different levels, given the 

occurrence of the scenario 10%- 50 year ground shaking event. Figure B-3 

presents this distribution. 

Figure B-3 Cumulative probability distribution for interstory drift response, 

conditioned on the 10%/50 year scenario event. 

Entering Figure B-3 one can read that if a 10%-50 year earthquake shaking 

event occurs, there is a 45% chance that the hypothetical buildings would 

experience a peak interstory drift of 2 inches or less. Conversely, one can 

read that there is a 55% chance that the drift experienced in such an event 

will be larger than 2 inches. Values of interstory drift at other probabilities 

of exceedance or nonexceedance can be similarly evaluated from the figure. 

The next step on the process is to calculate the probability of being in each of 

several damage states, given the structural response distribution shown in 

Figure B-3. Three local damage states (beam flange yielding, beam flange 

buckling and beam flange fracture) are considered. For this purpose, the 

same fragility data, previously presented in Figure A-10 is used. Since, for 
FEMA 445 B: Example Application of Seismic Performance Assessment 111 

this example, structural response is parameterized by interstory drift in 

inches, the data in Figure A-10 has been converted to these units, by 

assuming that a typical story has a height of 12 feet (144 inches). Figure B-4 

presents this converted fragility data. 

Figure B-4 Fragilities for local damage to steel moment frame connection assemblies 

Four global damage states (1% permanent drift, 2% permanent drift, 3% 

permanent drift and collapse) are also considered. Fragilities for these 

damage states were previously presented in Figure A-11. Figure B-5, 

presents this same data with the units of interstory drift converted from 

percent of story height to inches. As with the local fragilities, a story height 

of 144 inches has been assumed. 

Figure B-5 Fragilities for global damage to steel moment frame building 

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 1 2 3 4 5 6 7 8 9 10

Interstory Drift - Inches

Probability of Damage State

Initiation

Yielding Buckling Fracturing

0

0.2

0.4

0.6

0.8

1

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Peak Interstory Drift - Inches

Probability of Damage

State Initiation

1% Drift 2% Drift 3% Drift Collapse
112 B: Example Application of Seismic Performance Assessment FEMA 445 

Table B-4 Calculation of Probability of Each Local Damage State 

Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 

Interstory Drift 

Response Range 

( in.) 

Mid Value 

Interstory Drift 

( in.) 

Probability 

of 

Occurrence 

Conditional 

Probability of 

Yielding 

Incremental 

Probability of 

Yielding 

Conditional 

Probability of 

Buckling 

Incremental 

Probability of 

Buckling 

Conditional 

Probability of 

Fracturing 

Incremental 

Probability of 

Fracturing 

0-.5 0.25 0 0 0 0 0 0 0 

.5-1 0.75 0.08 0 0 0 0 0 0 

1-1.5 1.25 0.19 0.08 0.01 0 0 0 0 

1.5-2 1.75 0.18 0.97 0.18 0.01 0.001 0 0 

2-2.5 2.25 0.16 1.00 0.16 0.11 0.017 0 0 

2.5-3 2.75 0.11 1.00 0.11 0.41 0.045 0 0 

3-3.5 3.25 0.08 1.00 0.08 0.73 0.058 0.001 0.0001 

3.5-4 3.75 0.04 1.00 0.04 0.91 0.036 0.003 0.0001 

4-4.5 4.25 0.03 1.00 0.03 0.97 0.029 0.009 0.0003 

4.5-5 4.75 0.03 1.00 0.03 0.99 0.030 0.023 0.0007 

5-5.5 5.25 0.01 1.00 0.01 1.00 0.010 0.048 0.0005 

5.5-6 5.75 0.02 1.00 0.02 1.00 0.020 0.087 0.0017 

6-6.5 6.25 0.01 1.00 0.01 1.00 0.010 0.140 0.0014 

6.5-7 6.75 0.02 1.00 0.02 1.00 0.020 0.205 0.0041 

7-7.5 7.25 0.01 1.00 0.01 1.00 0.010 0.279 0.0028 

7.5-8 7.75 0.01 1.00 0.01 1.00 0.010 0.359 0.0036 

8-8.5 8.25 0.005 1.00 0.005 1.00 0.005 0.439 0.0026 

8.5-9 8.75 0.005 1.00 0.005 1 0.005 0.517 0.0026 

9-9.5 9.25 0.005 1.00 0.005 1 0.005 0.590 0.0033 

9.5-10 9.75 0.005 1.00 0.005 1 0.006 0.656 0.0033 

Total Probability of Damage State Initiation 0.740 0.317 0.027 

Total Probability of Damage State Occurrence 42.3% 29.0% 2.70% 

For a given damage state (e.g., beam flange buckling) the probability of 

being damaged to this damage state is evaluated as the conditional 

probability of the damage state (beam flange buckling) given a level of 

response times the probability of the response occurring, integrated over all 

possible levels of response. Table B-4 illustrates this calculation of the 

probability of each of the three local damage states, i.e., yielding, buckling 

and fracture. 

In Table B-4, the first column indicates the increments of response drift, over 

which the integration is being performed. The second column is the midrange value for each increment. The third range is the probability of 

occurrence of drift response within the increment. This is calculated as the 

difference of the probability of nonexceedance of the interstory drift at the 
FEMA 445 B: Example Application of Seismic Performance Assessment 113 

upper end of the increment, obtained from Figure B-3, and the probability of 

nonexceedance at the lower end of the increment, also obtained from Figure 

B-3. Columns 4 and 5 are the integration for the “yielding” state, columns 6 

and 7 for the “buckling” state, and columns 8 and 9 for the “fracturing” state. 

For each of these states, the first of the two columns represents the 

conditional probability that damage of the level indicated by this state or a 

more severe state will occur, given the drift response of the amount 

represented in column 2. This is evaluated from the data presented in Figure 

B-4. The second of the two columns is the incremental contribution to the 

total probability that any given connection in the structure will be damaged 

to the given state (or more severe state), calculated as the product of the 

conditional probability that the damage state will occur at the response level 

(e.g., column 4 for yielding) and the probability that the response level itself 

will be experienced (column 3). At the bottom of each of the columns, the 

total probability that any connection in the structure will be damaged to the 

given or more severe damage level is calculated as the sum of the 

incremental contributions in the column above. The last row shows the total 

probability that any connection in the structure will be damaged to the given 

level if the scenario 10%/50 year event is experienced, calculated as the 

difference between the total probability that the connection is damaged to a 

given or more severe level and the total probability that it is damaged to the 

next higher level. Thus, for this example, given the scenario event, there is a 

42% chance that any particular beam-column joint in the structure will 

initiate yielding but not buckling, a 29% chance that it will initiate beam 

flange buckling, but not fracturing and a 3% chance that it will initiate beam 

flange fracture. The chance that there would be no damage at all to any 

particular joint is estimated as 100% minus the sum of the probabilities for 

each of these damage states, or 26%. 

Table B-5 illustrates a similar calculation for the global damage states, of 

varying levels of permanent interstory drift and collapse. In this table, 

damage states consisting of 1%, 2%, and 3% permanent interstory drift and 

story collapse are shown. The conditional probability of each of these states 

initiating, as a function of response, are taken from the data shown in Figure 

B-5. Total probabilities of each of these damage states, given the scenario 

event is calculated, as described above for the local damage states. Total 

probabilities calculated are 24% for 1% permanent drift, 6% for 2% 

permanent drift, 2% for 3% permanent drift and 1% for collapse. The 

probability of no significant global damage is calculated as 100% minus the 

sum of the probabilities for each of these states, or 67%. 
114 B: Example Application of Seismic Performance Assessment FEMA 445 

Table B-5 Calculation of Probability of Each Global Damage State, Given the 10% - 50 Year Event 

Col 1 Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 Col 10 Col 11 

Respons

e Range 

(in) 

Mid 

Value 

(in) 

Probability 

of 

Occurrence 

Conditional 

Probability of 

1% Perm. Drift

Incremental 

Probability of 

1% Perm. Drift

Conditional 

Probability of 

2% Perm. Drift

Incremental 

Probability of 

2% Perm. Drift

Conditional 

Probability of 

3% Perm. Drift

Incremental 

Probability of 

3% Perm. Drift

Conditional 

Probability 

of Collapse

Incremental 

Probability 

of Collapse 

0-.5 0.25 0 0 0 0 0 0 0 0 0 

.5-1 0.75 0.08 0 0 0 0 0 0 0 0 

1-1.5 1.25 0.19 0 0 0 0 0 0 0 0 

1.5-2 1.75 0.18 0.05 0.009 0 0 0 0 0 0 

2-2.5 2.25 0.16 0.21 0.033 0 0 0 0 0 0 

2.5-3 2.75 0.11 0.44 0.048 0.01 0 0 0 0 0 

3-3.5 3.25 0.08 0.66 0.052 0.03 0.002 0.001 0 0.001 0 

3.5-4 3.75 0.04 0.81 0.032 0.08 0.003 0.003 0 0.004 0 

4-4.5 4.25 0.03 0.91 0.027 0.16 0.005 0.01 0 0.007 0 

4.5-5 4.75 0.03 0.95 0.029 0.26 0.008 0.02 0.001 0.013 0 

5-5.5 5.25 0.01 0.98 0.010 0.38 0.004 0.05 0.000 0.022 0 

5.5-6 5.75 0.02 0.99 0.020 0.50 0.010 0.09 0.002 0.033 0.001 

6-6.5 6.25 0.01 1.00 0.010 0.61 0.006 0.14 0.001 0.048 0.001 

6.5-7 6.75 0.02 1.00 0.020 0.70 0.014 0.21 0.004 0.065 0.001 

7-7.5 7.25 0.01 1.00 0.010 0.78 0.008 0.28 0.003 0.085 0.001 

7.5-8 7.75 0.01 1.00 0.010 0.84 0.008 0.36 0.004 0.108 0.001 

8-8.5 8.25 0.005 1.00 0.005 0.88 0.004 0.44 0.002 0.133 0.001 

8.5-9 8.75 0.005 1.00 0.005 0.92 0.005 0.52 0.003 0.159 0.001 

9-9.5 9.25 0.005 1.00 0.005 0.94 0.005 0.59 0.003 0.188 0.001 

9.5-10 9.75 0.005 1.00 0.005 0.96 0.005 0.66 0.003 0.218 0.001 

Total Probability of Damage State Initiation 0.330 0.088 0.027 0.009 

Total Probability of Damage State Occurrence 24.2% 6.1% 1.8% 0.9% 

Next, it is necessary to know the probable losses, given that a damage state is 

experienced. Figure B-6 indicates the probability of incurring various levels 

of repair cost for a damaged connection assembly, as a function of the 

damage state experienced. This same data was previously presented as 

Figure A-13. 

Table B-6 illustrates the calculation of probable repair cost per beam-column 

connection, for each of the three connection damage states: yielding, flange 

buckling and flange fracturing. This is accomplished by integrating over all 

possible individual connection repair costs, the probability that this repair 

cost would be experienced, given that the connection is damaged to the 

specified state. In Table B-6, the first two columns indicate the upper and 

lower bounds for the incremental repair costs over which the integration is 

performed. The third column gives the mid-range cost for the given 
FEMA 445 B: Example Application of Seismic Performance Assessment 115 

Figure B-6 Probability of Experiencing Various Repair Costs as Function of 

Connection Assembly Damage State 

Table B-6 Calculation of Probable Repair Cost, Given that a Connection Damage State is Experienced 

Col 1 Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 Col 10 Col 11 Col 12 

Repair Cost/Connection Yielding Buckling Fracturing 

Low High Mid-pt Prob. of 

NonExc. 

Prob. Of 

Occurrence

Incremental 

Probable 

Loss 

Prob. of 

NonExc. 

Prob. of 

Occurrence

Incremental 

Probable 

Loss 

Prob. of 

NonExc. 

Prob. of 

Occurrence

Incremental 

Probable Loss 

$- $75 $38 0.3868 0.3868 $14.50 0.0143 0.0143 $0.54 0.0026 0.0026 $0.10 

$75 $125 $100 0.5883 0.5883 $58.83 0.0323 0.0323 $3.23 0.0070 0.0070 $0.70 

$125 $250 $188 0.8202 0.2320 $43.49 0.0828 0.0506 $9.48 0.0229 0.0159 $2.99 

$250 $500 $375 0.9462 0.1260 $47.25 0.1777 0.0949 $35.57 0.0624 0.0395 $14.81 

$500 $750 $625 0.9780 0.0318 $19.88 0.2566 0.0789 $49.31 0.1030 0.0406 $25.37 

$750 $1,000 $875 0.9893 0.0113 $9.89 0.3220 0.0654 $57.24 0.1416 0.0387 $33.83 

$1,750 $2,000 $1,875 0.9986 0.0093 $17.40 0.5000 0.1780 $333.74 0.2706 0.1290 $241.88 

$2,750 $3,000 $2,875 0.9997 0.0010 $2.97 0.6065 0.1065 $306.30 0.3667 0.0961 $276.22 

$3,750 $4,000 $3,875 0.9999 0.0002 $0.86 0.6780 0.0715 $276.89 0.4409 0.0741 $287.33 

$4,750 $5,000 $4,875 1.0000 0.0001 $0.33 0.7294 0.0514 $250.38 0.5000 0.0591 $288.26 

$5,750 $6,000 $5,875 1.0000 0.0000 $0.14 0.7680 0.0387 $227.28 0.5484 0.0484 $284.18 

$6,750 $7,000 $6,875 1.0000 0.0000 $0.07 0.7982 0.0302 $207.28 0.5887 0.0404 $277.56 

$7,750 $8,000 $7,875 1.0000 0.0000 $0.04 0.8223 0.0241 $189.92 0.6230 0.0342 $269.67 

$8.750 $9,000 $8,875 1.0000 0.0000 $0.02 0.8420 0.0197 $174.78 0.6524 0.0294 $261.20 

$9,750 $10,000 $9,875 1.0000 0.0000 $0.01 0.8584 0.0164 $161.49 0.6780 0.0256 $252.57 

$10,000 $15,000 $12,500 1.0000 0.0000 $0.02 0.9104 0.0521 $650.65 0.7680 0.0900 $1,125.57 

$15,000 $20,000 $17,500 1.0000 0.0000 $0.00 0.9376 0.0272 $476.13 0.8223 0.0543 $949.68 

$20,000 $25,000 $22,500 1.0000 0.0000 $0.00 0.9539 0.0163 $366.23 0.8584 0.0360 $811.06 

$850,000 $900,000 $875,000 1.0000 0.0000 $0 1.0000 0.0000 $3.60 0.9997 0.0000 $35.50 

$900,000 $950,000 $925,000 1.0000 0.0000 $0 1.0000 0.0000 $3.09 0.9998 0.0000 $31.22 

$950,000 $1,000,000 $975,000 1.0000 0.0000 $0 1.0000 0.0000 $2.68 0.9998 0.0000 $27.61 

 $215.73 $6,397.12 $15,370.52 

0

0.2

0.4

0.6

0.8

1

0 5000 10000 15000 20000 25000

Repair Cost / Connection 

Probability of Nonexceedance

Yielding

Buckling

Fracture
116 B: Example Application of Seismic Performance Assessment FEMA 445 

increment. Columns 4, 7 and 10 indicate the probability of experiencing 

damage less severe than the high end of each incremental range for the yield, 

buckling and fracturing states, respectively. Columns 5, 8 and 11 indicate 

the probability of damage costing within each range, calculated as the 

difference between the probability of damage less severe than the high end of 

that range and the high end of the next lower range. Columns 6, 9 and 12 

indicate the incremental contribution to the total probable repair cost from 

the various ranges, calculated as the mid-range repair cost for each range 

factored by the probability of the cost being within the range. The total 

expected cost of repairing damage for the category is calculated as the sum of 

the incremental costs for each of the ranges and is approximately $215 per 

yielded connection, $6,400 per buckled connection and $15,000 per fractured 

connection. 

Table B-7 performs a similar integration to determine the probable costs 

associated with repair of global damage in the building, if the building is 

damaged to each of the global damage states: 1% permanent drift, 2% 

permanent drift, 3% permanent drift and collapse, respectively. For the 

purposes of this calculation it has arbitrarily been assumed that the median 

cost for repair of damage for each of these states is respectively $37.50 per 

square foot, $47 per square foot, $56 per square foot and $200 per square 

foot, respectively. Coefficients of variation for these repair costs have 

respectively been assumed as 40% for 1% drift, 50% for 2% and 3% drift and 

30% for the collapse state. The probable cost of repair for these states is 

respectively found to be $46/sq foot of story space for 1% permanent drift, 

$53/sq foot of story space for 2% story drift, $64/square foot of story space 

for 3% story drift and $210/square foot of building space for the collapse 

state. 

It should be noted that in this example, it has been assumed that the 

probability of experiencing given levels of local damage is uncoupled from 

the probability of experiencing particular levels of global damage and that 

the cost associated with repair of global damage and that related to repair of 

local damage are also uncoupled. In actuality, neither of these assumptions 

is correct and rather than using independent probabilities for these damage 

states, joint probability distributions should be used. Development of 

effective and practical methods of accounting for these joint probabilities is 

needed and will be conducted as part of the Phase 1 FEMA 445 program. 
FEMA 445 B: Example Application of Seismic Performance Assessment 117 

Table B-7 Calculation of Probable Repair Costs for Global Damage 

Repair Cost/Square 

Feet 

1% Permanent Drift 2% Permanent Drift 3% Permanent Drift Collapse 

Low High MidRange Prob. of 

NonExc. 

Prob. of 

Occurrence 

Incremental 

Probable 

Loss 

Prob. of 

NonExc.

Prob. of 

Occurrence 

Incremental 

Probable 

Loss 

Prob. of 

NonExc.

Prob. of 

Occurrence 

Incremental 

Probable 

Loss 

Prob. of 

NonExc. 

Prob. of 

Occurrence 

Incremental 

Probable 

Loss 

$0 $10 $5 0.000 0.000 $0.00 0.001 0.001 $0.01 0.000 0.000 $0.00 0.000 0.000 $0.00

$10 $20 $15 0.058 0.058 $0.86 0.044 0.043 $0.65 0.019 0.019 $0.29 0.000 0.000 $0.00

$20 $30 $25 0.288 0.230 $5.76 0.186 0.142 $3.55 0.104 0.085 $2.13 0.000 0.000 $0.00

$30 $40 $35 0.564 0.276 $9.65 0.376 0.189 $6.63 0.248 0.143 $5.02 0.000 0.000 $0.00

$40 $50 $45 0.764 0.200 $9.00 0.551 0.176 $7.91 0.407 0.159 $7.16 0.000 0.000 $0.00

$50 $60 $55 0.880 0.116 $6.38 0.689 0.138 $7.58 0.551 0.144 $7.95 0.000 0.000 $0.00

$60 $70 $65 0.941 0.061 $3.94 0.789 0.099 $6.47 0.669 0.118 $7.65 0.000 0.000 $0.01

$70 $80 $75 0.971 0.030 $2.27 0.857 0.069 $5.16 0.759 0.090 $6.78 0.001 0.001 $0.07

$80 $90 $85 0.986 0.015 $1.26 0.904 0.047 $3.95 0.826 0.067 $5.69 0.004 0.003 $0.23

$90 $100 $95 0.993 0.007 $0.68 0.935 0.031 $2.96 0.875 0.049 $4.63 0.010 0.007 $0.62

$100 $120 $110 0.998 0.005 $0.58 0.970 0.035 $3.83 0.935 0.060 $6.61 0.044 0.034 $3.73

$120 $130 $125 0.999 0.001 $0.11 0.979 0.009 $1.17 0.953 0.018 $2.24 0.076 0.031 $3.90

$130 $140 $135 1.000 0.000 $0.06 0.986 0.006 $0.86 0.966 0.013 $1.73 0.117 0.042 $5.63

$140 $150 $145 1.000 0.000 $0.03 0.990 0.004 $0.63 0.975 0.009 $1.33 0.169 0.052 $7.48

$150 $160 $155 1.000 0.000 $0.02 0.993 0.003 $0.46 0.982 0.007 $1.03 0.228 0.060 $9.25

$160 $170 $165 1.000 0.000 $0.01 0.995 0.002 $0.34 0.987 0.005 $0.79 0.294 0.066 $10.81

$170 $180 $175 1.000 0.000 $0.01 0.996 0.001 $0.25 0.990 0.003 $0.61 0.363 0.069 $12.03

$180 $190 $185 1.000 0.000 $0.00 0.997 0.001 $0.19 0.993 0.003 $0.47 0.432 0.069 $12.84

$190 $200 $195 1.000 0.000 $0.00 0.998 0.001 $0.14 0.994 0.002 $0.36 0.500 0.068 $13.24

$200 $250 $225 1.000 0.000 $0.00 1.000 0.001 $0.33 0.999 0.004 $0.94 0.772 0.272 $61.09

$250 $300 $275 1.000 0.000 $0.00 1.000 0.000 $0.08 1.000 0.001 $0.28 0.912 0.140 $38.56

$300 $350 $325 1.000 0.000 $0.00 1.000 0.000 $0.02 1.000 0.000 $0.09 0.969 0.057 $18.59

$350 $400 $375 1.000 0.000 $0.00 1.000 0.000 $0.01 1.000 0.000 $0.03 0.990 0.021 $7.74

$400 $450 $425 1.000 0.000 $0.00 1.000 0.000 $0.00 1.000 0.000 $0.01 0.997 0.007 $2.97

$450 $500 $475 1.000 0.000 $0.00 1.000 0.000 $0.00 1.000 0.000 $0.00 0.999 0.002 $1.10

$500 $550 $525 1.000 0.000 $0.00 1.000 0.000 $0.00 1.000 0.000 $0.00 1.000 0.001 $0.40

$550 $600 $575 1.000 0.000 $0.00 1.000 0.000 $0.00 1.000 0.000 $0.00 1.000 0.000 $0.14

 $40.63 $53.16 $63.82 $210.42

The final step is to compute the expected losses, given that the scenario event 

is experienced. This is performed by summing over all damage states, the 

probability that the damage state is experienced and the probable (expected) 

loss given that the state is experienced. Table B-8 illustrates this calculation. 

Total expected cost to repair the structure following the scenario event is 

found to be approximately $1,800,000, or approximately $31/ sq ft. 
118 B: Example Application of Seismic Performance Assessment FEMA 445 

Table B-8 Calculation of Expected Repair Cost, Given 10%/50-Year Event 

Col 1 Col 2 Col 3 Col 4 Col 5 Col 6 

Damage State Yielding 

Buckling Fracture 

Probability of 

Occurrence 

Probable Cost per 

Connection 

Expected Cost 

per Connection 

Expected 

Global Cost 

Total Expected 

Cost 

1% drift 0.423 $215.73 $91.25 n/a $9,855.22 

2% drift 0.290 $6,397.12 $1,855.16 n/a $200,357.81 

3% drift 0.027 $15,370.52 $415.00 n/a $44,820.43 

Collapse 0.243 n/a n/a $592,400.31 $592,400.31 

 0.061 n/a n/a $194,571.90 $194,571.90 

 0.018 n/a n/a $689,246.69 $689,246.69 

 0.009 n/a n/a $113,629.31 $113,629.31 

Aggregate of all damage states: $1,844,881.67 

The actual losses in any actual occurrence of the 10%-50 year event could 

vary substantially from these expected values depending on the actual value 

of the ground motion experienced at the site, given that the 10%/50 year 

event occurs, the actual response of the structure given this ground motion, 

the actual damage state that the structure experiences, the actual number of 

people present in the building, and the response time and efficiency of the 

owner, tenants and contractors in effecting repairs. Possible variability in 

each of these factors, including the variability in the ground motion, the 

variability in structural response, the variability in the damage state given the 

response, and the variability in the human factors, has been explicitly 

considered in the hazard, response, fragility and loss functions, as described 

above. However, the integration process results in an average or mean value 

of the loss, considering all this potential variability. Thus, there is a 

significant probability, on the order of 40%, that actual losses could be larger 

than this amount. Procedures for determining performance (losses) at other 

levels of confidence will be developed as part of the implementation of the 

Phase 1 FEMA 445 Program Plan. 
FEMA 445 C: Example Application Using Closed Form Solutions 119 

Appendix C 

Example Application of 

Seismic Performance Assessment 

Using Closed Form Solutions

This Appendix illustrates the application of a closed-form solution to the 

performance assessment process described in Appendix A. This example 

application is different from that presented in Appendix B and consists of the 

estimation of the annual average probability of earthquake-induced life loss 

for the hypothetical building. The closed-form solution is based on a 

procedure developed by Baker and Cornell (2003). Similar procedures have 

been developed to estimate other probable earthquake losses, using closedform solutions. All of these procedures require that the hazard, response, 

fragility and loss functions, described in Appendix A, be represented by 

simple functional forms that permit closed-form integration. The 

representation of these various functions, in simple form, necessarily entails 

some approximation, which affects to some extent the prediction of 

performance. However, for many applications the simplification obtained by 

an ability to perform a closed-form solution might compensate for any loss of 

accuracy in the solution. 

In this application, the same three-story, moment-resisting steel frame 

building that was the subject of evaluation using numerical integration 

procedures in Appendix B is used. The following assumptions and 

simplifications are made. The hazard function for the building site is 

represented in a power form as follows: 

( ) GM

k λ x k x ε − = 0 (C-1) 

where λ(x) is the annual frequency of exceedance of ground shaking equaling 

or exceeding intensity level x, k0 and k are numerical coefficients chosen to 

fit this functional form to the site hazard curve in the range of interest, e.g., 

the 1/100 to 1/1000 interval, and εGM is a lognormally distributed random 

variable representing epistemic uncertainty related to the ground motion 

hazard. This form of the hazard function appears as a straight line when log 

λ(x) is plotted vs log x (as shown in Figure C-1). 

Epistemic is that uncertainty that occurs due a lack of knowledge on the true 

values of causative factors for a physical behavior. For example, epistemic 
120 C: Example Application Using Closed Form Solutions FEMA 445 

uncertainty in ground motion hazard may result from a less than perfect 

knowledge of the mean slip rates on neighboring faults or of the depth and 

shear wave profiles of soils beneath a site. In Appendix A, such effects were 

simply termed uncertainty. Figure C-1 is a plot of the median estimate of the 

peak ground acceleration hazard curve for the site, previously shown in 

Figure A-3, plotted here in log-log coordinates. Also plotted in the figure is 

the explicit functional representation of the median estimate hazard curve, 

which has been fit to the natural curve by the function: 

λ(x) x ε GM

6 .00001 ˆ − = (C-2) 

where the coefficients k0 and k are respectively assigned values of 0.00001 

and 6. 

As can be seen, the functional form of the hazard curve represents the natural 

form of the hazard curve reasonably well for annual frequencies of 

exceedance ranging from 0.01 to 0.001. It diverges from the natural curve at 

extreme values. 

Figure C-2 is the fragility data for building collapse, previously presented as 

one of several global damage states in Figure B-5. As can be seen, this 

shows a median (50% probability) value for collapse at an interstory drift of 

14 inches. Figure C-3, previously shown as Figure B-2, is a response curve 

for the structure and indicates that the median value of peak ground 

acceleration at which an interstory drift of 14 inches is achieved has a value 

of approximately 1.25g. 

0.0001

0.001

0.01

0.1

1

0.01 0.1 1

Peak Ground Acceleration -g

Annual Probability of

Exceedance

median

function

Figure C-1 Median Hazard Curve for Site 
FEMA 445 C: Example Application Using Closed Form Solutions 121 

Figure C-2 Global fragility for hypothetical structure 

The closed form solution for the mean estimate of the annual frequency of 

collapse of the structure is given by the relationship: 

2

2

0 ˆ UT

k

k

collapse c E k e

β

λ η − = (C-3) 

where, k0 and k are the coefficients previously described in the discussion of 

the hazard curve and have values of 0.0001 and 6, respectively, ηc is the 

median value of the ground shaking intensity at which collapse occurs, in 

this case 1.25g, and βUT is the total dispersion considering all sources of 

epistemic and aleatory uncertainty and defined by the expression: 

2 2 2

,

2

,

2

,

2

UT U ,C R C U R R R UGM β = β + β + β + β + k β (C-4) 

0

0.2

0.4

0.6

0.8

1

0 10 20 30 40 50 60 70

Peak Interstory Drift - Inches

Probability of Damage State

Initiation

0

2

4

6

8

10

12

14

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Peak Ground Acceleration - g

Interstory Drift - %

Median 10% Conf. Level 90% Conf. Level

Figure C-3 Structural response curve for hypothetical building 
122 C: Example Application Using Closed Form Solutions FEMA 445 

where, k is the same hazard coefficient previously described, βU,C and βR,C are 

respectively the epistemic and aleatory uncertainty dispersions in structure 

capacity, βU,R and βR,R, are respectively the epistemic and aleatory 

uncertainty dispersions in structural response, and βUGM is the epistemic 

uncertainty in ground motion hazard, i.e., the dispersion of the random 

variable defined as εGM in Eq. C-1 above. Aleatory uncertainty quantifies 

random, event to event, variation in behavior that can not be ascribed to 

quantifiable parameters, i.e., aleatory uncertainty can be characterized as 

random variation or randomness. 

These various measures of dispersion are derived during the process of 

developing the hazard function, response function and damage functions, 

respectively, as previously described in Appendix A. For this example 

application, the values of these variances are as given in Table C-1. 

Table C-1 Epistemic and Aleatory Uncertainty for Example Building 

Quantity Epistemic βU Aleatory βR

Interstory Dift Capacity .2 .5 

Interstory Drift Response 35 .3 

Ground Motion Frequency .5 

Substituting these values into equation C-4, it is found that βUT has a value of 

3. Finally, substituting these values into equation C-2 is found that there is 

5x10-5 annual frequency of collapse. 

The annual frequency of life loss can be taken as the product of the annual 

frequency of collapse, times the probability of life loss given that collapse 

occurs. In a typical office building, during normal business hours, there is 

approximately one person for every 200 square feet of floor space. 

Earthquakes can occur at any hour of the day or night; however, buildings 

are occupied only about 25% of the time. Therefore, the mean average 

occupancy density of a building is on the order of one person per 800 square 

foot. Frame buildings of this type would typically collapse in a story type 

mechanism that involves a single story. Further, a story collapse may not be 

complete. If we assume that given collapse, there is a 50% chance that any 

person in the effected story would be a fatality and that persons on other 

floors would not be expected to suffer fatal injuries, we find that the mean 

expected number of fatalities given a collapse is the probability of collapse, 

calculated above as 5x10-5 per year, times the probable number of people in 

the affected story at the time of collapse, which is 25, times the conditional 

probability that each would be a fatality, given that their story collapses. 

This yields an expected number of fatalities per year of 6x10-4. 
FEMA 445 References 123 

References

This reference list is divided into two groups: (1) all publications cited in 

order of authors and year published; and (2) FEMA publications listed in 

order of report number. 

ARA, 2003, Progressive Collapse Guidelines, prepared by Applied Research 

Associates for the General Services Administration, Washington, D.C. 

ASCE, 1998, Handbook for the Seismic Evaluation of Buildings, a 

Prestandard, FEMA 310 Report, prepared by the American Society of 

Civil Engineers for the Federal Emergency Management Agency, 

Washington, D.C. 

ASCE, 2000, Prestandard and Commentary for the Seismic Rehabilitation of 

Buildings, FEMA 356 Report, prepared by the American Society of Civil 

Engineers for the Federal Emergency Management Agency, Washington, 

D.C. 

ASCE, 2002, Standard Methodology for Seismic Evaluation of Buildings.

Standard No. ASCE-31. American Society of Civil Engineers, Reston, 

Virginia. 

ATC, 1985, Earthquake Damage Evaluation Data for California, ATC-13 

Report, Applied Technology Council, Redwood City, California. 

ATC, 1996, Seismic Evaluation and Retrofit of Concrete Buildings, ATC-40 

Report, prepared for the California Seismic Safety Commission by the 

Applied Technology Council, Redwood City, California. 

ATC, 1997a, NEHRP Guidelines for the Seismic Rehabilitation of Buildings, 

FEMA 273 Report, prepared by the Applied Technology Council for the 

Building Seismic Safety Council, published by the Federal Emergency 

Management Agency, Washington, D.C. 

ATC, 1997b, NEHRP Commentary on the Guidelines for the Seismic 

Rehabilitation of Buildings, FEMA 274 Report, prepared by the Applied 

Technology Council, for the Building Seismic Safety Council, published 

by the Federal Emergency Management Agency, Washington, D.C. 
124 References FEMA 445 

ATC, 2005, Improvement of Nonlinear Static Seismic Analysis Procedures, 

FEMA 440 Report, prepared by the Applied Technology Council for the 

Federal Emergency Management Agency, Washington, D.C. 

Baker, J.W., and Cornell, C.A., 2003, Uncertainty Specification and 

Propagation for Loss Estimation Using FOSM Methods, Department of 

Civil Engineering, Stanford University, California. 

BSSC, 1999, Case Studies: An Assessment of the NEHRP Guidelines for the 

Seismic Rehabilitation of Buildings, FEMA 343 Report, prepared by the 

Building Seismic Safety Council for the Federal Emergency 

Management Agency, Washington, D.C. 

BSSC, 2003, NEHRP Recommended Provisions for Seismic Regulation of 

Buildings and Other Structures, FEMA 450 Report, prepared by the 

Building Seismic Safety Council for the Federal Emergency 

Management Agency, Washington, D.C. 

EERC, 1996, Performance-Based Seismic Design of Buildings – An Action 

Plan for Future Studies, FEMA 283 Report, prepared by the Earthquake 

Engineering Research Center for the Federal Emergency Management 

Agency, Washington, D.C. 

EERI, 2000, Action Plan for Performance-based Seismic Design. FEMA 349 

Report, prepared by the Earthquake Engineering Research Institute for 

the Federal Emergency Management Agency, Washington, D.C. 

EERI, 2002, Securing Society against Catastrophic Earthquake Losses,

prepared for the National Science Foundation by the Earthquake 

Engineering Research Institute, Oakland, California. 

EQE, 1999, Earthquake Risk Management: Toolkit for Decision-Makers, 

prepared by EQE International, Inc. for the California Seismic Safety 

Commission, Sacramento, California. 

NIBS, 1997, Multihazard Loss Estimating Methodology, HAZUS, prepared 

for the Federal Emergency Management Agency by the National 

Institute of Building Sciences, Washington, D.C. 

ICC, 2001, International Performance Code, International Code Council, 

Whittier, California. 

ICC, 2006, International Building Code, International Code Council, Falls 

Church, Virginia. 
FEMA 445 References 125 

NFPA, 2003, Building and Construction Safety Code, NFPA-5000 Report, 

National Fire Protection Association, Framingham, Massachusetts. 

Park, Y.J., and Ang, A.H-S., 1985, “Mechanistic seismic damage model for 

reinforced concrete,” Journal of Structural Engineering, Vol. 111, No. 4, 

American Society of Civil Engineers, Reston, Virginia, pp. 722-739. 

Porter, K.A., 2004, “Simplified PBEE to estimate economic seismic risk of 

buildings,” Proceedings of the International Workshop on PerformanceBased Seismic Design, Bled, Slovenia, Pacific Earthquake Engineering 

Research Center, Richmond, California. 

SAC, 2000a, Recommended Seismic Design Criteria for New Steel MomentFrame Buildings, FEMA 350 Report, prepared by the SAC Joint 

Venture, a partnership of the Structural Engineers Association of 

California, the Applied Technology Council, and California Universities 

for Research in Earthquake Engineering, for the Federal Emergency 

Management Agency, Washington, D.C. 

SAC, 2000b, Recommended Seismic Evaluation and Upgrade Criteria for 

Existing Welded Steel Moment-Frame Buildings, FEMA 351 Report, 

prepared by the SAC Joint Venture, a partnership of the Structural Engineers 

Association of California, the Applied Technology Council, and California 

Universities for Research in Earthquake Engineering, for the Federal 

Emergency Management Agency, Washington, D.C. 

SAC, 2000c, Recommended Post-earthquake Evaluation and Repair Criteria for 

Welded Steel Moment-Frame Buildings, FEMA 352 Report, prepared by the 

SAC Joint Venture, a partnership of the Structural Engineers Association of 

California, the Applied Technology Council, and California Universities for 

Research in Earthquake Engineering, for the Federal Emergency 

Management Agency, Washington, D.C. 

SEAOC, 1995, Vision 2000: Performance-Based Seismic Engineering of 

Buildings, Structural Engineers Association of California, Sacramento, 

California. 

VISCMA, 2002, Installing Seismic Restraints for Mechanical Equipment, FEMA 

412 Report, prepared by the Vibration Isolation and Seismic Control 

Manufacturer’s Association for the Federal Emergency Management 

Agency, Washington, D.C. 
126 References FEMA 445 

VISCMA, 2004a, Installing Seismic Restraints for Electrical Equipment, FEMA 

413 Report, prepared by the Vibration Isolation and Seismic Control 

Manufacturer’s Association for the Federal Emergency Management 

Agency, Washington, D.C. 

VISCMA, 2004b, Installing Seismic Restraints for Piping and Ducts, FEMA 416 

Report, prepared by the Vibration Isolation and Seismic Control 

Manufacturer’s Association for the Federal Emergency Management 

Agency, Washington, D.C. 
FEMA 445 References 127 

FEMA Publications 

FEMA 273, 1997, NEHRP Guidelines for the Seismic Rehabilitation of 

Buildings, prepared by the Applied Technology Council for the Building 

Seismic Safety Council, published by the Federal Emergency 

Management Agency, Washington, D.C. 

FEMA 274, 1997, NEHRP Commentary on the Guidelines for the Seismic 

Rehabilitation of Buildings, prepared by the Applied Technology 

Council, for the Building Seismic Safety Council, published by the 

Federal Emergency Management Agency, Washington, D.C. 

FEMA 283, 1996, Performance-Based Seismic Design of Buildings – An 

Action Plan for Future Studies, prepared by the Earthquake Engineering 

Research Center for the Federal Emergency Management Agency, 

Washington, D.C. 

FEMA 310, 1998, Handbook for the Seismic Evaluation of Buildings, a 

Prestandard, prepared by the American Society of Civil Engineers for 

the Federal Emergency Management Agency, Washington, D.C. 

FEMA 343, 1999, Case Studies: An Assessment of the NEHRP Guidelines 

for the Seismic Rehabilitation of Buildings, FEMA 343 Report, prepared 

by the Building Seismic Safety Council for the Federal Emergency 

Management Agency, Washington, D.C. 

FEMA 349, 2000, Action Plan for Performance-based Seismic Design, 

prepared by the Earthquake Engineering Research Institute for the 

Federal Emergency Management Agency, Washington, D.C. 

FEMA 350, 2000, Recommended Seismic Design Criteria for New Steel 

Moment-Frame Buildings, prepared by the SAC Joint Venture, a 

partnership of the Structural Engineers Association of California, the 

Applied Technology Council, and California Universities for Research in 

Earthquake Engineering, for the Federal Emergency Management 

Agency, Washington, D.C. 

FEMA 351, 2000, Recommended Seismic Evaluation and Upgrade Criteria 

for Existing Welded Steel Moment-Frame Buildings, prepared by the 

SAC Joint Venture, a partnership of the Structural Engineers Association 

of California, the Applied Technology Council, and California 

Universities for Research in Earthquake Engineering, for the Federal 

Emergency Management Agency, Washington, D.C. 
128 References FEMA 445 

FEMA 352, 2000, Recommended Post-earthquake Evaluation and Repair 

Criteria for Welded Steel Moment-Frame Buildings, prepared by the 

SAC Joint Venture, a partnership of the Structural Engineers Association 

of California, the Applied Technology Council, and California 

Universities for Research in Earthquake Engineering, for the Federal 

Emergency Management Agency, Washington, D.C. 

FEMA 356, 2000, Prestandard and Commentary for the Seismic 

Rehabilitation of Buildings, prepared by the American Society of Civil 

Engineers for the Federal Emergency Management Agency, Washington, 

D.C. 

FEMA 412, 2002, Installing Seismic Restraints for Mechanical Equipment,

prepared by the Vibration Isolation and Seismic Control Manufacturer’s 

Association for the Federal Emergency Management Agency, 

Washington, D.C. 

FEMA 413, 2004, Installing Seismic Restraints for Electrical Equipment, 

prepared by the Vibration Isolation and Seismic Control Manufacturer’s 

Association for the Federal Emergency Management Agency, 

Washington, D.C. 

FEMA 416, 2004, Installing Seismic Restraints for Piping and Ducts,

prepared by the Vibration Isolation and Seismic Control Manufacturer’s 

Association for the Federal Emergency Management Agency, 

Washington, D.C. 

FEMA 440, 2005, Improvement of Inelastic Analysis Procedures, prepared 

by the Applied Technology Council for the Federal Emergency 

Management Agency, Washington, D.C. 

FEMA 450, 2003, NEHRP Recommended Provisions for Seismic Regulation 

of Buildings and Other Structures, prepared by the Building Seismic 

Safety Council for the Federal Emergency Management Agency, 

Washington, D.C. 
FEMA 445 Project Participants 129 

Project Participants

Project Management 

Christopher Rojahn 

(Project Executive Director) 

Applied Technology Council 

201 Redwood Shores Parkway, 

Suite 240 

Redwood City, California 94065 

Ronald O. Hamburger 

(Project Technical Director) 

Simpson Gumpertz & Heger 

The Landmark @ One Market, 

Suite 600 

San Francisco, California 94105 

FEMA Oversight 

Mike Mahoney (Project Officer) 

Federal Emergency 

Management Agency 

500 C Street, SW, Room 416 

Washington, D.C. 20472 

Robert D. Hanson (Tech. Monitor) 

Federal Emergency 

Management Agency 

2926 Saklan Indian Drive 

Walnut Creek, California 94595 

Project Management Committee (PMC) 

Christopher Rojahn (Chair) 

Ronald Hamburger (Co-Chair) 

Jon A. Heintz* 

Applied Technology Council 

201 Redwood Shores Parkway, 

Suite 240 

Redwood City, California 94065 

Peter May 

(University of Washington) 

21817 SE 20th Street 

Sammamish , Washington 98075 

Jack P. Moehle University of 

California at Berkeley 

3444 Echo Springs Road 

Lafayette, California 94549 

Maryann T. Phipps** 

ESTRUCTURE 

8331 Kent Court, Suite 100 

El Cerrito, California 94530 

Jon Traw 

Traw Associates Consulting 

14435 Eastridge Drive 

Whittier, California 90602 

*Ex-officio 

**ATC Board Representative 

Steering Committee 

William T. Holmes (Chair) 

Rutherford & Chekene 

427 Thirteenth Street 

Oakland, California 94612 

Dan Abrams 

Mid-America Earthquake Center 

University of Illinois 

1245 Newmark Civil Engr. Lab 

205 N. Mathews 

Urbana, Illinois 61801 
130 Project Participants FEMA 445 

Deborah B. Beck 

Beck Creative Strategies LLC 

531 Main Street, Suite 313 

New York, New York 10044 

Randall Berdine 

Fannie Mae 

3900 Wisconsin Avenue, NW 

Washington, D.C. 20016-2892 

Roger D. Borcherdt 

U.S. Geological Survey 

345 Middlefield Road, MS977 

Menlo Park, California 94025 

Jimmy Brothers 

City of Decatur, Building 

Department 

402 Lee Street NE, 4th Fl., 

City Hall Tower 

Decatur, Alabama 35601 

Michel Bruneau 

MCEER, University at Buffalo 

105 Red Jacket Quadrangle 

Buffalo, New York 14261-0025 

Terry Dooley 

Morley Builders 

2901 28th Street, Suite 100 

Santa Monica, California 90405 

Mohammed Ettouney 

Weidlinger Associates, Inc. 

375 Hudson Street 

New York, New York 10014 

John Gillengerten 

Office of Statewide Health 

Planning and Development 

1600 9th St., Room 420 

Sacramento, California 95814 

Barry Goodno 

Georgia Institute of Technology 

School of Civil and 

Environmental Engineering 

Atlanta, Georgia 30332 

William J. Petak 

University of Southern California 

School of Policy Planning and 

Development 

Lewis Hall 214 

650 Childs Way 

Los Angeles, California 90089 

Randy Schreitmueller 

FM Global 

1301 Atwood Avenue 

Johnston, Rhode Island 02919 

James W. Sealy, Architect 

1320 Prudential Drive, No 101 

Dallas, Texas 75235-4117 

Structural Performance Products Team 

Andrew S. Whittaker (Leader) 

University at Buffalo 

Dept. of Civil Engineering 

230 Ketter Hall 

Buffalo, New York 14260 

Gregory Deierlein 

Stanford University 

Dept. of Civil & Environmental 

Engineering 

240 Terman Engineering Center 

Stanford, California 94305-4020 

Andre Filiatrault 

MCEER, University of Buffalo 

105 Red Jacket Quadrangle 

Buffalo, New York 14261-0025 

John Hopper 

Magnesson Klemencic Associates 

1301 Fifth Avenue, Suite 3200 

Seattle, Washington 98101 

Andrew T. Merovich 

A. T. Merovich & Associates, Inc. 

1950 Addison Street, Suite 205 

Berkeley, California 94704 
FEMA 445 Project Participants 131 

Nonstructural Performance Products Team 

Robert E. Bachman (Leader) 

Consulting Structural Engineer 

880 Dartmouth Street 

San Francisco, California 94134 

David Bonowitz 

Office of Court Construction and 

Management 

Judicial Council of California 

Administrative Office of the 

Courts 

455 Golden Gate Avenue 

San Francisco, California 94102 

Philip J. Caldwell 

Square D Company 

1990 Sandifer Blvd. 

Seneca, South Carolina 29687 

Andre Filiatrault 

MCEER, University of Buffalo 

105 Red Jacket Quadrangle 

Buffalo, New York 14261-0025 

Robert P. Kennedy 

RPK Structural Mechanics 

Consulting, Inc. 

28625 Mountain Meadow Road 

Escondido, California 92026 

Gary McGavin 

McGavin Architecture 

20608 South Street, Suite C 

Tehachapi, California 93561 

Eduardo Miranda 

Stanford University 

Civil & Environmental 

Engineering 

Terman Room 293 

Stanford, California 94305-3707 

Keith Porter 

Consulting Engineer 

769 N. Michigan Ave. 

Pasadena, California 91104 

Risk Management Products Team 

Craig D. Comartin (Leader) 

Comartin Engineers 

7683 Andrea Avenue 

Stockton, California 95207-1705 

C. Allin Cornell 

Stanford University 

110 Coquito Way 

Portola Valley, California 94028 

Gee Heckscher 

Architecture Resources Group 

Pier 9, The Embarcadero 

San Francisco, California 94111 

Charles Kircher 

Kircher & Associates, Consulting 

Engineers 

1121 San Antonio Road, 

Suite D-202 

Palo Alto, California 94303-4311 

Mr. Gary McGavin 

McGavin Architecture 

447 LaVerne Street 

Redlands, CA 92373

Brian J. Meacham (Assoc. Leader) 

Arup 

1500 West Park Drive, Suite 180 

Westborough, Massachusetts 

01581 

Farzad Naeim 

John A. Martin & Associates, Inc. 

1212 S. Flower Street, 4th Floor 

Los Angeles, CA 90015