FEMA

Rapid Visual Screening of 

Buildings for Potential 

Seismic Hazards

A Handbook

FEMA 154, Edition 2 / March 2002
NATIONAL EARTHQUAKE HAZARDS REDUCTION PROGRAM

Second Edition 

RAPID VISUAL SCREENING OF BUILDINGS 

FOR POTENTIAL SEISMIC HAZARDS: 

A HANDBOOK 

APPLIED TECHNOLOGY COUNCIL 

555 Twin Dolphin Drive, Suite 550 

Redwood City, California 94065 

Funded by 

FEMA

Washington, DC
ATC-21 UPDATE PROJECT PARTICIPANTS 

PRINCIPAL INVESTIGATOR 

Christopher Rojahn 

CO-PRINCIPAL INVESTIGATOR 

Charles Scawthorn 

PROJECT ADVISORY PANEL 

Thalia Anagnos 

John Baals 

James Cagley 

Melvyn Green 

Terry Hughes 

Anne S. Kiremidjian 

Joan MacQuarrie 

Chris D. Poland 

Lawrence D. Reaveley 

Doug Smits 

Ted Winstead 

CONSULTANTS 

Kent M. David 

William T. Holmes 

Stephanie A. King 

Keith Porter 

Vincent Prabis 

Richard Ranous 

Nilesh Shome 

ATC STAFF 

A. Gerald Brady 

Peter N. Mork 

Bernadette A. Mosby 

Michelle S. Schwartzbach 

APPLIED TECHNOLOGY COUNCIL 

The Applied Technology Council (ATC) is a 

nonprofit, tax-exempt corporation established in 

1971 through the efforts of the Structural Engineers 

Association of California. ATC’s mission is to 

develop state-of-the-art, user-friendly engineering 

resources and applications for use in mitigating the 

effects of natural and other hazards on the built 

environment. ATC also identifies and encourages 

needed research and develops consensus opinions 

on structural engineering issues in a nonproprietary format. ATC thereby fulfills a unique 

role in funded information transfer. 

ATC is guided by a Board of Directors 

consisting of representatives appointed by the 

American Society of Civil Engineers, the National 

Council of Structural Engineers Associations, the 

Structural Engineers Association of California, the 

Western Council of Structural Engineers 

Associations, and four at-large representatives 

concerned with the practice of structural 

engineering. Each director serves a three-year term. 

Project management and administration are 

carried out by a full-time Executive Director and 

support staff. Project work is conducted by a wide 

range of highly qualified consulting professionals, 

thus incorporating the experience of many 

individuals from academia, research, and 

professional practice who would not be available 

from any single organization. Funding for ATC 

projects is obtained from government agencies and 

from the private sector in the form of tax-deductible 

contributions. 

2001-2002 Board of Directors 

Andrew T. Merovich, President 

James R. Cagley, Vice President 

Stephen H. Pelham, Secretary/Treasurer 

Arthur N. L. Chiu, Past President 

Steven M. Baldridge 

Patrick Buscovich

Anthony B. Court 

Edwin T. Dean 

James M. Delahay 

Melvyn Green 

Richard L. Hess 

Christopher P. Jones 

Maryann T. Phipps 

Lawrence D. Reaveley 

ATC DISCLAIMER 

While the information presented in this report is 

believed to be correct, ATC and the sponsoring 

agency assume no responsibility for its accuracy or 

for the opinions expressed herein. The materials 

presented in this publication should not be used or 

relied upon for any specific application without 

competent examination and verification of its 

accuracy, suitability, and applicability by qualified 

professionals. Users of information from this 

publication assume all liability arising from such 

use. 
FEMA 154 FEMA Foreword iii 

FEMA Foreword 

The Federal Emergency Management Agency 

(FEMA) is pleased to present the second edition of 

the widely used Rapid Visual Screening of 

Buildings for Potential Seismic Hazards: A 

Handbook, and its companion, Supporting 

Documentation. The policy of improving reports 

and manuals that deal with the seismic safety of 

existing buildings as soon as new information and 

adequate resources are available is thus being 

reaffirmed. Users should take note of some major 

differences between the two editions of the 

Handbook. The technical content of the new 

edition is based more on experiential data and less 

on expert judgment than was the case in the earlier 

edition, as is explained in the Supporting 

Documentation. From the presentational point of 

view, the Handbook retains much of the material 

of the earlier edition, but the material has been 

rather thoroughly rearranged to further facilitate 

the step-by-step process of conducting the rapid 

visual screening of a building. By far the most 

significant difference between the two editions, 

however, is the need for a higher level of 

engineering understanding and expertise on the 

part of the users of the second edition. This shift 

has been caused primarily by the difficulty 

experienced by users of the first edition in 

identifying the lateral-force-resisting system of a 

building without entry—a critical decision of the 

rapid visual screening process. The contents of 

the Supporting Documentation volume have also 

been enriched to reflect the technical advances in 

the Handbook. 

FEMA and the Project Officer wish to express 

their gratitude to the members of the Project 

Advisory Panel, to the technical and workshop 

consultants, to the project management, and to the 

report production and editing staff for their 

expertise and dedication in the upgrading of these 

two volumes. 

The Federal Emergency Management Agency 

FEMA 154 Preface v 

Preface 

In August 1999 the Federal Emergency 

Management Agency (FEMA) awarded the 

Applied Technology Council (ATC) a two-year 

contract to update the FEMA 154 report, Rapid 

Visual Screening of Buildings for Potential 

Seismic Hazards: A Handbook, and the 

companion FEMA-155 report, Rapid Visual 

Screening of Buildings for Potential Seismic 

Hazards: Supporting Documentation, both of 

which were originally published in 1988. 

The impetus for the project stemmed in part 

from the general recommendation in the FEMA 

315 report, Seismic Rehabilitation of Buildings: 

Strategic Plan 2005, to update periodically all 

existing reports in the FEMA-developed series on 

the seismic evaluation and rehabilitation of 

existing buildings. In addition, a vast amount of 

information had been developed since 1988, 

including: (1) new knowledge about the 

performance of buildings during damaging 

earthquakes, including the 1989 Loma Prieta and 

1994 Northridge earthquakes; (2) new knowledge 

about seismic hazards, including updated national 

seismic hazard maps published by the U. S. 

Geological Survey in 1996; (3) other new seismic 

evaluation and damage prediction tools, such as 

the FEMA 310 report, Handbook for the Seismic 

Evaluation of Buildings – a Prestandard, (an 

updated version of FEMA 178, NEHRP Handbook 

for the Seismic Evaluation of Existing Buildings), 

and HAZUS, FEMA’s tool for estimating potential 

losses from natural disasters; and (4) experience 

from the widespread use of the original FEMA 

154 Handbook by federal, state and municipal 

agencies, and others. 

The project included the following tasks: 

(1) an effort to obtain users feedback, which was 

executed through the distribution of a voluntary 

FEMA 154 Users Feedback Form to organizations 

that had ordered or were known to have used 

FEMA 154 (the Feedback Form was also posted 

on ATC’s web site); (2) a review of available 

information on the seismic performance of 

buildings, including a detailed review of the 

HAZUS fragility curves and an effort to correlate 

the relationship between results from the use of 

both the FEMA 154 rapid visual screening 

procedure and the FEMA 178 detailed seismic 

evaluation procedures on the same buildings; 

(3) a Users Workshop midway in the project to 

learn first hand the problems and successes of 

organizations that had used the rapid visual 

screening procedure on buildings under their 

jurisdiction; (4) updating of the original FEMA 

154 Handbook to create the second edition; and 

(5) updating of the original FEMA 155 Supporting 

Documentation report to create the second edition. 

This second edition of the FEMA 154 

Handbook provides a standard rapid visual 

screening procedure to identify, inventory, and 

rank buildings that are potentially seismically 

hazardous. The scoring system has been revised, 

based on new information, and the Handbook has 

been shortened and focused to facilitate 

implementation. The technical basis for the rapid 

visual screening procedure, including a summary 

of results from the efforts to solicit user feedback, 

is documented in the companion second edition of 

the FEMA 155 report, Rapid Visual Screening of 

Buildings for Potential Seismic Hazards: 

Supporting Documentation.

ATC gratefully acknowledges the personnel 

involved in developing the second editions of the 

FEMA 154 and FEMA 155 reports. Charles 

Scawthorn served as Co-Principal Investigator and 

Project Director. He was assisted by Kent David, 

Vincent Prabis, Richard A. Ranous, and Nilesh 

Shome, who served as Technical Consultants. 

Members of the Project Advisory Panel, who 

provided overall review and guidance for the 

project, were: Thalia Anagnos, John Baals, James 

R. Cagley (ATC Board Representative), Melvyn 

Green, Terry Hughes, Anne S. Kiremidjian, Joan 

MacQuarrie, Chris D. Poland, Lawrence D. 

Reaveley, Doug Smits, and Ted Winstead. 

William T. Holmes served as facilitator for the 

Users Workshop, and Keith Porter served as 

recorder. Stephanie A. King verified the Basic 

Structural Hazard Scores and the Score Modifiers. 

A. Gerald Brady, Peter N. Mork, and Michelle 

Schwartzbach provided report editing and 

production services. The affiliations of these 

individuals are provided in the list of project 

participants. 

ATC also gratefully acknowledges the 

valuable assistance, support, and cooperation 

provided by Ugo Morelli, FEMA Project Officer. 

In addition, ATC acknowledges participants in the 
vi Preface FEMA 154 

FEMA 154 Users Workshop, which included, in 

addition to the project personnel listed above, the 

following individuals: Al Berstein, U. S. Bureau 

of Reclamation; Amitabha Datta, General Services 

Administration; Ben Emam, Amazon.com; 

Richard K. Eisner, California Office of Emergency 

Services; Ali Fattah, City of San Diego; Brian 

Kehoe, Wiss Janney Elstner Associates, Inc.; 

David Leung, City and County of San Francisco; 

Douglas McCall, Marx/Okubo; Richard Silva, 

National Park Service; Howard Simpson, Simpson 

Gumpertz & Heger Inc.; Steven Sweeney, U. S. 

Army Civil Engineering Research Laboratory; 

Christine Theodooropoulos, University of Oregon; 

and Zan Turner, City and County of San 

Francisco. Those persons who responded to 

ATC’s request to complete the voluntary FEMA 

154 Users Feedback form are also gratefully 

acknowledged. 

Christopher Rojahn, Principal Investigator 

ATC Executive Director 
FEMA 154 Summary and Application vii 

Summary and Application 

This FEMA 154 Report, Rapid Visual Screening 

of Buildings for Potential Seismic Hazards: A 

Handbook, is the first of a two-volume publication 

on a recommended methodology for rapid visual 

screening of buildings for potential seismic 

hazards. The technical basis for the methodology, 

including the scoring system and its development, 

are contained in the companion FEMA 155 report, 

Rapid Visual Screening of Buildings for Potential 

Seismic Hazards: Supporting Documentation. 

Both this document and the companion document 

are second editions of similar documents 

published by FEMA in 1988. 

The rapid visual screening procedure (RVS) 

has been developed for a broad audience, 

including building officials and inspectors, and 

government agency and private-sector building 

owners (hereinafter, the "RVS authority"), to 

identify, inventory, and rank buildings that are 

potentially seismically hazardous. Although RVS 

is applicable to all buildings, its principal purpose 

is to identify (1) older buildings designed and 

constructed before the adoption of adequate 

seismic design and detailing requirements, (2) 

buildings on soft or poor soils, or (3) buildings 

having performance characteristics that negatively 

influence their seismic response. Once identified 

as potentially hazardous, such buildings should be 

further evaluated by a design professional 

experienced in seismic design to determine if, in 

fact, they are seismically hazardous. 

The RVS uses a methodology based on a 

“sidewalk survey” of a building and a Data 

Collection Form, which the person conducting the 

survey (hereafter referred to as the screener) 

completes, based on visual observation of the 

building from the exterior, and if possible, the 

interior. The Data Collection Form includes space 

for documenting building identification 

information, including its use and size, a 

photograph of the building, sketches, and 

documentation of pertinent data related to seismic 

performance, including the development of a 

numeric seismic hazard score. 

Once the decision to conduct rapid visual 

screening for a community or group of buildings 

has been made by the RVS authority, the 

screening effort can be expedited by pre-planning, 

including the training of screeners, and careful 

overall management of the process. 

Completion of the Data Collection Form in the 

field begins with identifying the primary structural 

lateral-load-resisting system and structural 

materials of the building. Basic Structural Hazard 

Scores for various building types are provided on 

the form, and the screener circles the appropriate 

one. For many buildings, viewed only from the 

exterior, this important decision requires the 

screener to be trained and experienced in building 

construction. The screener modifies the Basic 

Structural Hazard Score by identifying and 

circling Score Modifiers, which are related to 

observed performance attributes, and which are 

then added (or subtracted) to the Basic Structural 

Hazard Score to arrive at a final Structural Score, 

S. The Basic Structural Hazard Score, Score 

Modifiers, and final Structural Score, S, all relate 

to the probability of building collapse, should 

severe ground shaking occur (that is, a ground 

shaking level equivalent to that currently used in 

the seismic design of new buildings). Final S

scores typically range from 0 to 7, with higher S

scores corresponding to better expected seismic 

performance. 

Use of the RVS on a community-wide basis 

enables the RVS authority to divide screened 

buildings into two categories: those that are 

expected to have acceptable seismic performance, 

and those that may be seismically hazardous and 

should be studied further. An S score of 2 is 

suggested as a “cut-off”, based on present seismic 

design criteria. Using this cut-off level, buildings 

having an S score of 2 or less should be 

investigated by a design professional experienced 

in seismic design. 

The procedure presented in this Handbook is 

meant to be the preliminary screening phase of a 

multi-phase procedure for identifying potentially 

hazardous buildings. Buildings identified by this 

procedure must be analyzed in more detail by an 

experienced seismic design professional. Because 

rapid visual screening is designed to be performed 

from the street, with interior inspection not always 

possible, hazardous details will not always be 

visible, and seismically hazardous buildings may 

not be identified as such. Conversely, buildings 

initially identified as potentially hazardous by 

RVS may prove to be adequate. 

FEMA 154 Contents ix 

Contents 

FEMA Foreword................................................................................................................................................ iii 

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

Summary and Application ................................................................................................................................ vii 

List of Figures.................................................................................................................................................. xiii 

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

Illustration Credits ............................................................................................................................................xxi 

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

1.1 Background..........................................................................................................................................1 

1.2 Screening Procedure Purpose, Overview, and Scope..........................................................................2

1.3 Companion FEMA 155 Report............................................................................................................3 

1.4 Relationship of FEMA 154 to Other Documents in the FEMA Existing Building Series ..................4 

1.5 Uses of RVS Survey Results ...............................................................................................................4 

1.6 How to Use this Handbook..................................................................................................................4 

2. Planning and Managing Rapid Visual Screening..........................................................................................5 

2.1 Screening Implementation Sequence...................................................................................................5 

2.2 Budget Development and Cost Estimation..........................................................................................6 

2.3 Pre-Field Planning ...............................................................................................................................6 

2.4 Selection and Review of the Data Collection Form ............................................................................7 

2.4.1 Determination of Seismicity Region ......................................................................................8

2.4.2 Determination of Key Seismic Code Adoption Dates and Other Considerations ..................8 

2.4.3 Determination of Cut-Off Score ...........................................................................................10 

2.5 Qualifications and Training for Screeners.........................................................................................11 

2.6 Acquisition and Review of Pre-Field Data........................................................................................11 

2.6.1 Assessor’s Files ....................................................................................................................11 

2.6.2 Building Department Files....................................................................................................12 

2.6.3 Sanborn Maps.......................................................................................................................12 

2.6.4 Municipal Databases.............................................................................................................15 

2.6.5 Previous Studies ...................................................................................................................15 

2.6.6 Soils Information ..................................................................................................................15 

2.7 Review of Construction Documents..................................................................................................17 

2.8 Field Screening of Buildings .............................................................................................................18 

2.9 Checking the Quality and Filing the Field Data in the Record-Keeping System ..............................18 

3. Completing the Data Collection Form ........................................................................................................19 

3.1 Introduction .......................................................................................................................................19 

3.2 Verifying and Updating the Building Identification Information......................................................20 

3.2.1 Number of Stories.................................................................................................................20 

3.2.2 Year Built .............................................................................................................................20 

3.2.3 Screener Identification..........................................................................................................20 

3.2.4 Total Floor Area ...................................................................................................................21 

3.3 Sketching the Plan and Elevation Views ...........................................................................................21 

3.4 Determining Soil Type ......................................................................................................................21 

3.5 Determining and Documenting Occupancy.......................................................................................22 

3.5.1 Occupancy ............................................................................................................................22 

3.5.2 Occupancy Load...................................................................................................................23 
x Contents FEMA 154 

3.6 Identifying Potential Nonstructural Falling Hazards.........................................................................23 

3.7 Identifying the Lateral-Load-Resisting System and Documenting the Related Basic 

Structural Score .................................................................................................................................24 

3.7.1 Fifteen Building Types Considered by the RVS Procedure and Related Basic 

Structural Scores...................................................................................................................24 

3.7.2 Identifying the Lateral-Force-Resisting System...................................................................25 

3.7.3 Interior Inspections...............................................................................................................36 

3.7.4 Screening Buildings with More Than One Lateral-Force Resisting System........................37 

3.8 Identifying Seismic Performance Attributes and Recording Score Modifiers ..................................38 

3.8.1 Mid-Rise Buildings...............................................................................................................38 

3.8.2 High-Rise Buildings .............................................................................................................38 

3.8.3 Vertical Irregularity ..............................................................................................................38 

3.8.4 Plan Irregularity....................................................................................................................40 

3.8.5 Pre-Code ...............................................................................................................................40 

3.8.6 Post-Benchmark....................................................................................................................41 

3.8.7 Soil Type C, D, or E .............................................................................................................41 

3.9 Determining the Final Score..............................................................................................................41 

3.10 Photographing the Building...............................................................................................................42 

3.11 Comments Section.............................................................................................................................42 

4. Using the RVS Procedure Results...............................................................................................................43 

4.1 Interpretation of RVS Score ..............................................................................................................43 

4.2 Selection of RVS “Cut-Off” Score....................................................................................................43 

4.3 Prior Uses of the RVS Procedure ......................................................................................................44 

4.4 Other Possible Uses of the RVS Procedure.......................................................................................45 

4.4.1 Using RVS Scores as a Basis for Hazardous Building Mitigation Programs.......................45 

4.4.2 Using RVS Data in Community Building Inventory Development .....................................46 

4.4.3 Using RVS Data to Plan Postearthquake Building-Safety-Evaluation Efforts.....................46 

4.4.4 Resources Needed for the Various Uses of the RVS Procedure...........................................46 

5. Example Application of Rapid Visual Screening........................................................................................49 

5.1 Step 1: Budget and Cost Estimation .................................................................................................49 

5.2 Step 2: Pre-Field Planning................................................................................................................50 

5.3 Step 3: Selection and Review of the Data Collection Form .............................................................50 

5.4 Step 4: Qualifications and Training for Screeners............................................................................51 

5.5 Step 5: Acquisition and Review of Pre-Field Data...........................................................................51 

5.6 Step 6: Review of Construction Documents.....................................................................................55 

5.7 Step 7: Field Screening of Buildings................................................................................................55 

5.8 Step 8: Transferring the RVS Field Data to the Electronic Building RVS Database .......................64 

Appendix A: Maps Showing Seismicity Regions.............................................................................................65 

Appendix B: Data Collection Forms and Quick Reference Guide ...................................................................77 

Appendix C: Review of Design and Construction Drawings ...........................................................................83 

Appendix D: Exterior Screening for Seismic System and Age ........................................................................85 

D.1 Introduction .......................................................................................................................................85 

D.2 What to Look for and How to Find It ................................................................................................85 

D.3 Identification of Building Age...........................................................................................................85 

D.4 Identification of Structural Type .......................................................................................................88 

D.5 Characteristics of Exposed Construction Materials...........................................................................95 

Appendix E: Characteristics and Earthquake Performance of RVS Building Types........................................99 

E.1 Introduction .......................................................................................................................................99 

E.2 Wood Frame (W1, W2) .....................................................................................................................99 
FEMA 154 Contents xi 

E.2.1 Characteristics ......................................................................................................................99 

E.2.2 Typical Earthquake Damage ..............................................................................................100 

E.2.3 Common Rehabilitation Techniques ..................................................................................102 

E.3 Steel Frames (S1, S2) ......................................................................................................................103 

E.3.1 Characteristics ....................................................................................................................103 

E.3.2 Typical Earthquake Damage ..............................................................................................105 

E.3.3 Common Rehabilitation Techniques ..................................................................................105 

E.4 Light Metal (S3) ..............................................................................................................................106 

E.4.1 Characteristics ....................................................................................................................106 

E.4.2 Typical Earthquake Damage ..............................................................................................107 

E.5 Steel Frame with Concrete Shear Wall (S4)....................................................................................107 

E.5.1 Characteristics ....................................................................................................................107 

E.5.2 Typical Earthquake Damage ..............................................................................................108 

E.6 Steel Frame with Unreinforced Masonry Infill (S5)........................................................................108 

E.6.1 Characteristics ....................................................................................................................108 

E.6.2 Typical Earthquake Damage ..............................................................................................109 

E.6.3 Common Rehabilitation Techniques ..................................................................................110 

E.7 Concrete Moment-Resisting Frame (C1).........................................................................................110 

E.7.1 Characteristics ....................................................................................................................110 

E.7.2 Typical Earthquake Damage ..............................................................................................112 

E.7.3 Common Rehabilitation Techniques ..................................................................................113 

E.8 Concrete Shear Wall (C2)................................................................................................................113 

E.8.1 Characteristics ....................................................................................................................113 

E.8.2 Typical Types of Earthquake Damage ...............................................................................114 

E.8.3 Common Rehabilitation......................................................................................................114 

E.9 Concrete Frame with Unreinforced Masonry Infill (C3).................................................................114 

E.9.1 Characteristics ....................................................................................................................114 

E.9.2 Typical Earthquake Damage ..............................................................................................116 

E.9.3 Common Rehabilitation Techniques ..................................................................................116 

E.10 Tilt-up Structures (PC1) ..................................................................................................................116 

E.10.1 Characteristics ....................................................................................................................116 

E.10.2 Typical Earthquake Damage ..............................................................................................117 

E.10.3 Common Rehabilitation Techniques ..................................................................................118 

E.11 Precast Concrete Frame (PC2).........................................................................................................118 

E.11.1 Characteristics ....................................................................................................................118 

E.11.2 Typical Earthquake Damage ..............................................................................................120 

E.11.3 Common Rehabilitation Techniques ..................................................................................120 

E.12 Reinforced Masonry (RM1 and RM2) ............................................................................................121 

E.12.1 Characteristics ....................................................................................................................121 

E.12.2 Typical Earthquake Damage ..............................................................................................121 

E.12.3 Common Rehabilitation Techniques ..................................................................................121 

E.13 Unreinforced Masonry (URM)........................................................................................................122 

E.13.1 Characteristics ....................................................................................................................122 

E.13.2 Typical Earthquake Damage ..............................................................................................126 

E.13.3 Common Rehabilitation Techniques ..................................................................................126 

Appendix F: Earthquakes and How Buildings Resist Them...........................................................................129 

F.1 The Nature of Earthquakes ..............................................................................................................129 

F.2 Seismicity of the United States........................................................................................................130 

F.3 Earthquake Effects...........................................................................................................................131 

F.4 How Buildings Resist Earthquakes .................................................................................................134 

References........................................................................................................................................................137 

Project Participants ..........................................................................................................................................139 

FEMA 154 List of Figures xiii 

List of Figures 

Figure 1-1 High, moderate, and low seismicity regions of the conterminous United States. A 

different RVS Data Collection Form has been developed for each of these regions.................1 

Figure 1-2 Data Collection Forms for the three designated seismicity regions (low, moderate, 

and high). ...................................................................................................................................3 

Figure 2-1 Rapid visual screening implementation sequence. ....................................................................5

Figure 2-2 Example RVS Data Collection Form (high seismicity).............................................................7 

Figure 2-3 Sections 1 and 2 of Quick Reference Guide (for use with Data Collection Form)..................10 

Figure 2-4 Building identification portion of RVS Data Collection Form................................................11 

Figure 2-5 Example Sanborn map showing building information for a city block. ..................................12 

Figure 2-6 Key to Sanborn map symbols. ...............................................................................................13 

Figure 2-7 Sanborn map and corresponding aerial photograph of a city block.........................................14 

Figure 2-8 Photographs of elevation views of buildings shown in Figure 2-7..........................................15 

Figure 2-9 Examples of in-house screen displays of municipal databases................................................16 

Figure 2-10 Location on Data Collection Form where soil type information is recorded...........................17 

Figure 3-1 Example RVS Data Collection Form (high seismicity)...........................................................19 

Figure 3-2 Portion of Data Collection Form for documenting building identification. ............................20 

Figure 3-3 Sample Data Collection Form showing location for sketches of building plan and 

elevation views. .......................................................................................................................21 

Figure 3-4 Location on Data Collection Form where soil type information is documented (circled).......21 

Figure 3-5 Occupancy portion of Data Collection Form...........................................................................22 

Figure 3-6 Portion of Data Collection Form for documenting nonstructural falling hazards. ..................23 

Figure 3-7 Portion of Data Collection Form containing Basic Structural Hazard Scores. ........................25 

Figure 3-8 Typical frame structure. Features include: large window spans, window openings on 

many sides, and clearly visible column-beam grid pattern......................................................35 

Figure 3-9 Typical bearing wall structure. Features include small window span, at least two 

mostly solid walls, and thick load-bearing walls. ....................................................................35 

Figure 3-10 Frame and bearing wall structures ...........................................................................................36 

Figure 3-11 Interior view showing fireproofed columns and beams, which indicate a steel building 

(S1, S2, or S4)..........................................................................................................................37 
xiv List of Figures FEMA 154 

Figure 3-12 Interior view showing concrete columns and girders, which indicate a concrete moment 

frame (C1). .............................................................................................................................. 37 

Figure 3-13 Portion of Data Collection Form containing attributes that modify performance and 

associated score modifiers....................................................................................................... 38 

Figure 3-14 Elevation views showing vertical irregularities, with arrows indicating locations 

of particular concern................................................................................................................ 39 

Figure 3-15 Example of setbacks and a soft first story ............................................................................... 39 

Figure 3-16 Example of soft story conditions, where parking requirements result in large 

weak openings. ........................................................................................................................ 40 

Figure 3-17 Plan views of various building configurations showing plan irregularities; arrows 

indicate possible areas of damage. .......................................................................................... 40 

Figure 3-18 Example of a building, with a plan irregularity, with two wings meeting at right angles....... 41 

Figure 3-19 Example of a building, triangular in plan, subject to torsion. ................................................. 41 

Figure 3-20 Location on Data Collection Form where the final score, comments, and an indication 

if the building needs detailed evaluation are documented....................................................... 42 

Figure 5-1 Screen capture of USGS web page showing SA values for 0.2 sec and 1.0 sec for ground 

motions having 2% probability of being exceeded in 50 years............................................... 50 

Figure 5-2 High seismicity Data Collection Form selected for Anyplace, USA ...................................... 52 

Figure 5-3 Quick Reference Guide for Anyplace USA showing entries for years in which seismic 

codes were first adopted and enforced and benchmark years. ................................................ 53 

Figure 5-4 Property information at example site in city’s geographic information system...................... 54 

Figure 5-5 Exterior view of 3703 Roxbury Street .................................................................................... 56 

Figure 5-6 Close-up view of 3703 Roxbury Street exterior showing perimeter braced steel framing...... 56 

Figure 5-7 Building identification portion of Data Collection Form for Example 1, 

3703 Roxbury Street................................................................................................................ 56 

Figure 5-8 Completed Data Collection Form for Example 1, 3703 Roxbury Street................................. 57 

Figure 5-9 Exterior view of 3711 Roxbury............................................................................................... 58 

Figure 5-10 Close-up view of 3711 Roxbury Street building exterior showing infill 

frame construction................................................................................................................... 58 

Figure 5-11 Completed Data Collection Form for Example 2, 3711 Roxbury Street................................. 59 

Figure 5-12 Exterior view of 5020 Ebony Drive ........................................................................................ 60 

Figure 5-13 Completed Data Collection Form for Example 3, 5020 Ebony Drive .................................... 61 

Figure 5-14 Exterior view of 1450 Addison Avenue.................................................................................. 62 
FEMA 154 List of Figures xv 

Figure 5-15 Building identification portion of Data Collection Form for Example 4, 1450 Addison 

Avenue.....................................................................................................................................62 

Figure 5-16 Completed Data Collection Form for Example 4, 1450 Addison Avenue ..............................62 

Figure A-1 Seismicity Regions of the Conterminous United States ..........................................................66 

Figure A-2 Seismicity Regions in California, Idaho, Nevada, Oregon, and Washington..........................67 

Figure A-3 Seismicity Regions in Arizona, Montana, Utah, and Wyoming..............................................68 

Figure A-4 Seismicity Regions in Colorado, Kansas, New Mexico, Oklahoma, and Texas......................69 

Figure A-5 Seismicity Regions in Iowa, Michigan, Minnesota, Nebraska, North Dakota, 

South Dakota and Wisconsin...................................................................................................70

Figure A-6 Seismicity Regions in Illinois, Indiana, Kentucky, Missouri, and Ohio..................................71 

Figure A-7 Seismicity Regions in Alabama, Arkansas, Louisiana, Mississippi, and Tennessee ...............72 

Figure A-8 Seismicity Regions in Connecticut, Maine, Massachusetts, New Hampshire, Rhode 

Island, and Vermont.................................................................................................................73 

Figure A-9 Seismicity Regions in Delaware, Maryland, New Jersey, Pennsylvania, Virginia, and 

West Virginia...........................................................................................................................74 

Figure A-10 Seismicity Regions in Florida, Georgia, North Carolina, and South Carolina ........................75 

Figure A-11 Seismicity Regions in Alaska and Hawaii ...............................................................................76 

Figure D-1 Photos showing basic construction, in steel-frame buildings and reinforced 

concrete-frame buildings. ........................................................................................................91 

Figure D-2 Building with exterior columns covered with a façade material..............................................94 

Figure D-3 Detail of the column façade of Figure D-2. .............................................................................94 

Figure D-4 Building with both shear walls (in the short direction) and frames (in the long direction) .....94 

Figure D-5 Regular, full-height joints in a building’s wall indicate a concrete tilt-up. .............................95 

Figure D-6 Reinforced masonry wall showing no course of header bricks (a row of visible brick ends). 95 

Figure D-7 Reinforced masonry building with exterior wall of concrete masonry units, or concrete 

blocks.......................................................................................................................................95 

Figure D-8 A 1970s renovated façade hides a URM bearing-wall structure..............................................95 

Figure D-9 A concrete shear-wall structure with a 1960s renovated façade. .............................................96 

Figure D-10 URM wall showing header courses (identified by arrows) and two washer plates 

indicating wall anchors. ...........................................................................................................96 

Figure D-11 Drawing of two types of masonry pattern showing header bricks...........................................96 
xvi List of Figures FEMA 154 

Figure D-12 Diagram of common reinforced masonry construction. Bricks are left out of the bottom 

course at intervals to create cleanout holes, then inserted before grouting ............................. 97 

Figure D-13 Brick veneer panels. ................................................................................................................ 97 

Figure D-14 Hollow clay tile wall with punctured tiles............................................................................... 97 

Figure D-15 Sheet metal siding with masonry pattern................................................................................. 97 

Figure D-16 Asphalt siding with brick pattern. ........................................................................................... 98 

Figure D-17 Pre-1940 cast-in-place concrete with formwork pattern. ........................................................ 98 

Figure E-1 Single family residence (an example of the W1 identifier, light wood-frame residential 

and commercial buildings less than 5000 square feet). ........................................................... 99 

Figure E-2 Larger wood-framed structure, typically with room-width spans (W2, light, wood-frame 

buildings greater than 5000 square feet). ................................................................................ 99 

Figure E-3 Drawing of wood stud frame construction. ........................................................................... 100 

Figure E-4 Stud wall, wood-framed house.............................................................................................. 101 

Figure E-5 Drawing of timber pole framed house................................................................................... 101 

Figure E-6 Timber pole framed house..................................................................................................... 101 

Figure E-7 House off its foundation, 1983 Coalinga earthquake. ........................................................... 101 

Figure E-8 Failed cripple stud wall, 1992 Big Bear earthquake.............................................................. 102 

Figure E-9 Failure of post and pier foundation, Humbolt County. ......................................................... 102 

Figure E-10 Seismic strengthening of a cripple wall, with plywood sheathing. ....................................... 103 

Figure E-11 Drawing of steel moment-resisting frame building............................................................... 103 

Figure E-12 Braced frame configurations. ................................................................................................ 104 

Figure E-13 Braced steel frame, with chevron and diagonal braces. The braces and steel frames are 

usually covered by finish material after the steel is erected. ................................................. 104 

Figure E-14 Chevron bracing in steel building under construction........................................................... 104 

Figure E-15 Rehabilitation of a concrete parking structure using exterior X-braced steel frames............ 105 

Figure E-16 Use of a braced frame to rehabilitate an unreinforced masonry building.............................. 106 

Figure E-17 Drawing of light metal construction...................................................................................... 106 

Figure E-18 Connection of metal siding to light metal frame with rows of screws (encircled)................ 107 

Figure E-19 Prefabricated metal building (S3, light metal building). ....................................................... 107 

Figure E-20 Drawing of steel frame with interior concrete shear-walls.................................................... 108 
FEMA 154 List of Figures xvii 

Figure E-21 Concrete shear wall on building exterior. ..............................................................................108 

Figure E-22 Close-up of exterior shear wall damage during a major earthquake......................................108 

Figure E-23 Drawing of steel frame with URM infill................................................................................109 

Figure E-24 Example of steel frame with URM infill walls (S5). .............................................................110 

Figure E-25 Drawing of concrete moment-resisting frame building .........................................................111 

Figure E-26 Extreme example of ductility in concrete, 1994 Northridge earthquake. ..............................111 

Figure E-27 Example of ductile reinforced concrete column, 1994 Northridge earthquake; horizontal 

ties would need to be closer for greater demands. .................................................................112 

Figure E-28 Concrete moment-resisting frame building (C1) with exposed concrete, deep beams, 

wide columns (and with architectural window framing) .......................................................112 

Figure E-29 Locations of failures at beam-to-column joints in nonductile frames, 1994 Northridge 

earthquake..............................................................................................................................113 

Figure E-30 Drawing of concrete shear-wall building...............................................................................114 

Figure E-31 Tall concrete shear-wall building: walls connected by damaged spandrel beams................115 

Figure E-32 Shear-wall damage, 1989 Loma Prieta earthquake................................................................115 

Figure E-33 Concrete frame with URM infill............................................................................................115 

Figure E-34 Blow-up (lower photo) of distant view of C3 building (upper photo) showing concrete 

frame with URM infill (left wall), and face brick (right wall)...............................................115 

Figure E-35 Drawing of tilt-up construction typical of the western United States. Tilt-up 

construction in the eastern United States may incorporate a steel frame...............................116 

Figure E-36 Tilt-up industrial building, 1970s. .........................................................................................117 

Figure E-37 Tilt-up industrial building, mid- to late 1980s.......................................................................117 

Figure E-38 Tilt-up construction anchorage failure...................................................................................117 

Figure E-39 Result of failure of the roof beam anchorage to the wall in tilt-up building..........................117 

Figure E-40 Newly installed anchorage of roof beam to wall in tilt-up building. .....................................118 

Figure E-41 Drawing of precast concrete frame building..........................................................................119 

Figure E-42 Typical precast column cover on a steel or concrete moment frame. ....................................120 

Figure E-43 Exposed precast double-T sections and overlapping beams are indicative of 

precast frames ........................................................................................................................120 

Figure E-44 Example of precast double-T section during installation.......................................................120 
xviii List of Figures FEMA 154 

Figure E-45 Precast structural cross; installation joints are at sections where bending is minimum 

during high seismic demand.................................................................................................. 120

Figure E-46 Modern reinforced brick masonry......................................................................................... 121 

Figure E-47 Drawing of unreinforced masonry bearing-wall building, 2-story........................................ 122 

Figure E-48 Drawing of unreinforced masonry bearing-wall building, 4-story........................................ 123 

Figure E-49 Drawing of unreinforced masonry bearing-wall building, 6-story........................................ 124 

Figure E-50 East coast URM bearing-wall building. ................................................................................ 124 

Figure E-51 West coast URM bearing-wall building................................................................................ 124 

Figure E-52 Drawings of typical window head features in URM bearing-wall buildings. ....................... 125 

Figure E-53 Parapet failure leaving an uneven roof line, due to inadequate anchorage, 1989 Loma 

Prieta earthquake. .................................................................................................................. 126 

Figure E-54 Damaged URM building, 1992 Big Bear earthquake............................................................ 126 

Figure E-55 Upper: Two existing anchors above three new wall anchors at floor line using 

decorative washer plates. Lower: Rehabilitation techniques include closely spaced 

anchors at floor and roof levels. ............................................................................................ 127 

Figure F-1 The separate tectonic plates comprising the earth’s crust superimposed on a map of 

the world................................................................................................................................ 129 

Figure F-2 Seismicity of the conterminous United States 1977-1997. This reproduction shows 

earthquake locations without regard to magnitude or depth. The San Andreas fault and 

other plate boundaries are indicated with white lines............................................................ 131 

Figure F-3 Seismicity of Alaska 1977 – 1997. The white line close to most of the earthquakes is 

the plate boundary, on the ocean floor, between the Pacific and North America plates. ...... 132 

Figure F-4 Seismicity of Hawaii 1977 – 1997. ...................................................................................... 132. 

Figure F-5 Mid-rise building collapse, 1985 Mexico City earthquake. .................................................. 133 

Figure F-6 Near-field effects, 1992 Landers earthquake, showing house (white arrow) close to 

surface faulting (black arrow); the insert shows a house interior.......................................... 134 

Figure F-7 Collapsed chimney with damaged roof, 1987 Whittier Narrows earthquake........................ 134 

Figure F-8 House that slid off foundation, 1994 Northridge earthquake. ............................................... 135 

Figure F-9 Collapsed cripple stud walls dropped this house to the ground, 1992 Landers and Big 

Bear earthquakes. .................................................................................................................. 135 

Figure F-10 This house has settled to the ground due to collapse of its post and pier foundation............ 135 

Figure F-11 Collapse of unreinforced masonry bearing wall, 1933 Long Beach earthquake................... 135 

Figure F-12 Collapse of a tilt-up bearing wall, 1994 Northridge earthquake. .......................................... 135 
FEMA 154 List of Tables xix 

List of Tables 

Table 2-1 Regions of Seismicity with Corresponding Spectral Acceleration Response 

(from FEMA 310)......................................................................................................................8 

Table 2-2 Benchmark Years for RVS Procedure Building Types (from FEMA 310). ..............................9 

Table 2-3 Checklist of Issues to be Considered During Pre-Field Work Review of the Data 

Collection Form .......................................................................................................................10 

Table 2-4 Checklist of Field Equipment Needed for Rapid Visual Screening.........................................18 

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past 

Earthquakes..............................................................................................................................26 

Table 4-1 Matrix of Personnel and Material Resources Needed for Various FEMA 154 RVS 

Applications.............................................................................................................................47 

Table D-1 Photographs, Architectural Characteristics, and Age of Residential Buildings.......................86 

Table D-2 Illustrations, Architectural Characteristics, and Age of Commercial Structures .....................87 

Table D-3 Photographs, Architectural Characteristics, and Age of Miscellaneous Structures.................90 

Table D-4 Most Likely Structural Types for Pre-1930 Buildings ............................................................92 

Table D-5 Most Likely Structural Types for 1930-1945 Buildings..........................................................92 

Table D-6 Most Likely Structural Types for 1945-1960 Buildings..........................................................93 

Table D-7 Most Likely Structural Types for Post-1960 Buildings...........................................................93 

FEMA-154 Illustration Credits xxi 

Illustration Credits 

Figures Credit 

1-1, A-1 to 11 Maps credited to Nilesh Shome / ABS Consulting / EQE Engineers / USGS 

5-5, 6, 12, 14, F-11 Richard Ranous / ABS Consulting / EQE Engineers 

2-1,8; 

3-10 to 12, 15, 16, 18, 19; 

Table 3-1, Building Type 

W1, W2, S1 to S5, C1 to 

C3, PC1 (top), PC2, 

RM1, RM2, URM; 

5-9, 10, 

D-1 to 5; 

E-1, 2, 4, 6 to 10, 13 to 16, 

17 to 19, 21, 22, 24, 26 to 

29, 32 to 34, 36 to 40, 42, 

44, 46, 50, 51, 53 to 55; 

F-5 to 10, 12; 

Table D-1c to e; Table D-2 

b to o; Table D-3a to e, h 

Charles Scawthorn / ABS Consulting / EQE Engineers 

2-5, 6, 7 Sanborn Maps 

2-9 Oakland, California and Mecklenberg County, North Carolina, web pages 

3-8, 9; E-43, 45 Drawings by Kit Wong 

5-1, F-1 to 4 USGS web site 

5-3 Los Angeles/San Pedro, California; city GIS 

D-6, 8, 9, 10 

D-13 to 17; Table D-1a, b; 

Table D-3f, g 

Photographs by Kit Wong 

D-7 Robert Bruce 

D-11, 12 Allen, E., 1985, Fundamentals of Building Construction and Methods, John 

Wiley and sons, New York. 

E-3, 23, 25,30; 

E-35, 41, 47, 48, 49 

Lagorio, H., Friedman, H., and K. Wong (1986). Issues for Seismic 

Strengthening of Existing Buildings: A Practical Guide for Architects.

Center for Environmental Design, University of California at Berkeley. 

E-5, 12 Drawing from National Multihazard Survey Instructions. FEMA, TR-84.

E-11, 20 Steinbrugge, K. (1982). Earthquakes, Volcanoes, and Tsunamis, An 

Anatomy of Hazards. Skandia American Group, New York. 

E-31 James Stratta 

E-52 Ramsay/Sleeper Architectural Graphic Standards, Seventh Edition (1981). 

R.T. Packard, AIA, ed., John Wiley & Sons, New York. 

Table D-2a A Field Guide to American Architecture (1980), The New American 

Library, Inc., New York. 

Table 3-1, Building Type 

PC1 (lower) 

Earthquake Engineering Research Institute. 

E-39 Anonymous, but greatly appreciated 

FEMA-154 1: Introduction 1 

Chapter 1 

Introduction 

1.1 Background 

Rapid visual screening of buildings for potential 

seismic hazards, as described herein, originated in 

1988 with the publication of the FEMA 154 

Report, Rapid Visual Screening of Buildings for 

Potential Seismic Hazards: A Handbook. Written 

for a broad audience ranging from engineers and 

building officials to appropriately trained 

nonprofessionals, the Handbook provided a 

“sidewalk survey” approach that enabled users to 

classify surveyed buildings into two categories: 

those acceptable as to risk to life safety or those 

that may be seismically hazardous and should be 

evaluated in more detail by a design professional 

experienced in seismic design. 

During the decade following publication of the 

first edition of the FEMA 154 Handbook, the rapid 

visual screening (RVS) procedure was used by 

private-sector organizations and government 

agencies to evaluate more than 70,000 buildings 

nationwide (ATC, 2002). This widespread 

application provided important information about 

the purposes for which the document 

was used, the ease-of-use of the 

document, and perspectives on the 

accuracy of the scoring system upon 

which the procedure was based. 

Concurrent with the widespread 

use of the document, damaging 

earthquakes occurred in California 

and elsewhere, and extensive 

research and development efforts 

were carried out under the National 

Earthquake Hazards Reduction 

Program (NEHRP). These efforts 

yielded important new data on the 

performance of buildings in 

earthquakes, and on the expected 

distribution, severity, and occurrence 

of earthquake-induced ground 

shaking. 

The data and information 

gathered during the first decade after 

publication (experience in applying 

the original Handbook, new building 

earthquake performance data, and 

new ground shaking information) 

have been used to update and improve the rapid 

visual screening procedure provided in this second 

edition of the FEMA 154 Report, Rapid Visual 

Screening of Buildings for Potential Seismic 

Hazards: A Handbook. The revised RVS 

procedure retains the same framework and 

approach of the original procedure, but 

incorporates a revised scoring system compatible 

with the ground motion criteria in the FEMA 310 

Report, Handbook for Seismic Evaluation of 

Buildings—A Prestandard (ASCE, 1998), and the 

damage estimation data provided in the recently 

developed FEMA-funded HAZUS damage and 

loss estimation methodology (NIBS, 1999). As in 

the original Handbook, a Data Collection Form is 

provided for each of three seismicity regions: low, 

moderate, and high. However, the boundaries of 

the low, moderate, and high seismicity regions in 

the original Handbook have been modified (Figure 

1-1), reflecting new knowledge on the expected 

distribution, severity, and occurrence of 

earthquake ground shaking, and a change in the 

Figure 1-1 High, moderate, and low seismicity regions of the conterminous 

United States. A different RVS Data Collection Form has been 

developed for each of these regions. Enlarged maps are available 

in Appendix A. 

Note: Seismicity regions are based on ground motions having 

a 2% probability of exceedance in 50 years. 
2 1: Introduction FEMA 154 

recurrence interval considered, from a 475-year 

average return period (corresponding to ground 

motions having a 10% probability of exceedance 

in 50 years) to a 2475-year average return period 

(corresponding to ground motions having a 2% 

probability of excedance in 50 years). 

This second edition of the FEMA 154 

Handbook has been shortened and focused to 

facilitate implementation. Other improvements 

include: 

• guidance on planning and managing an RVS 

survey, including the training of screeners and 

the acquisition of data from assessor files and 

other sources to obtain more reliable 

information on age, structural system, and 

occupancy; 

• more guidance for identifying the structural 

(lateral-load-resisting) system in the field; 

• the use of interior inspection or pre-survey 

reviews of building plans to identify (or 

verify) a building’s lateral-load-resisting 

system; 

• updated Basic Structural Hazard Scores and 

Score Modifiers that are derived from 

analytical calculations and recently developed 

HAZUS fragility curves for the model 

building types considered by the RVS 

methodology; 

• the use of new seismic hazard information that 

is compatible with seismic hazard criteria 

specified in other related FEMA documents 

(see Section 1.4 below); and 

• a revised Data Collection Form that provides 

space for documenting soil type, additional 

options for documenting falling hazards, and 

an expanded list of occupancy types. 

1.2 Screening Procedure Purpose, 

Overview, and Scope 

The RVS procedure presented in this Handbook

has been formulated to identify, inventory, and 

rank buildings that are potentially seismically 

hazardous. Developed for a broad audience that 

includes building officials and inspectors, 

government agencies, design professionals, 

private-sector building owners (particularly those 

that own or operate clusters or groups of 

buildings), faculty members who use the RVS 

procedure as a training tool, and informed 

appropriately trained, members of the public, the 

RVS procedure can be implemented relatively 

quickly and inexpensively to develop a list of 

potentially hazardous buildings without the high 

cost of a detailed seismic analysis of individual 

buildings. If a building receives a high score (i.e., 

above a specified cut-off score, as discussed later 

in this Handbook), the building is considered to 

have adequate seismic resistance. If a building 

receives a low score on the basis of this RVS 

procedure, it should be evaluated by a professional 

engineer having experience or training in seismic 

design. On the basis of this detailed inspection, 

engineering analyses, and other detailed 

procedures, a final determination of the seismic 

adequacy and need for rehabilitation can be made. 

During the planning stage, which is discussed 

in Chapter 2, the organization that is conducting 

the RVS procedure (hereinafter, the “RVS 

authority”) will need to specify how the results 

from the survey will be used. If the RVS authority 

determines that a low score automatically requires 

that further study be performed by a professional 

engineer, then some acceptable level of 

qualification held by the inspectors performing the 

screening will be necessary. RVS projects have a 

wide range of goals and they have constraints on 

budget, completion date and accuracy, which must 

be considered by the RVS authority as it selects 

qualification requirements of the screening 

personnel. Under most circumstances, a wellplanned and thorough RVS project will require 

engineers to perform the inspections. In any case, 

the program should be overseen by a design 

professional knowledgeable in seismic design for 

quality assurance purposes. 

The RVS procedure in this Handbook is 

designed to be implemented without performing 

structural analysis calculations. The RVS 

procedure utilizes a scoring system that requires 

the user to (1) identify the primary structural 

lateral-load-resisting system; and (2) identify 

building attributes that modify the seismic 

performance expected of this lateral-load-resisting 

system. The inspection, data collection, and 

decision-making process typically will occur at the 

building site, taking an average of 15 to 30 

minutes per building (30 minutes to one hour if 

access to the interior is available). Results are 

recorded on one of three Data Collection Forms 

(Figure 1-2), depending on the seismicity of the 

region being surveyed. The Data Collection Form, 

described in greater detail in Chapter 3, includes 

space for documenting building identification 

information, including its use and size, a 

photograph of the building, sketches, and 

documentation of pertinent data related to seismic 

performance, including the development of a 
FEMA 154 1: Introduction 3 

numeric seismic hazard score. 

The scores are based on average 

expected ground shaking levels for 

the seismicity region as well as the 

seismic design and construction 

practices for that region1

. 

Buildings may be reviewed from 

the sidewalk without the benefit of 

building entry, structural 

drawings, or structural 

calculations. Reliability and 

confidence in building attribute 

determination are increased, 

however, if the structural framing 

system can be verified during 

interior inspection, or on the basis 

of a review of construction 

documents. 

The RVS procedure is 

intended to be applicable 

nationwide, for all conventional 

building types. Bridges, large 

towers, and other non-building 

structure types, however, are not 

covered by the procedure. Due to 

budget or other constraints, some 

RVS authorities may wish to 

restrict their RVS to identifying 

building types that they consider 

the most hazardous, such as 

unreinforced masonry or 

nonductile concrete buildings. 

However, it is recommended, at 

least initially, that all conventional 

building types be considered, and 

that elimination of certain building 

types from the screening be well 

documented and supported with 

office calculations and field 

survey data that justify their 

elimination. It is possible that, in some cases, 

even buildings designed to modern codes, such as 

those with configurations that induce extreme 

torsional response and those with abrupt changes 

in stiffness, may be potentially hazardous. 

 

1

 Seismic design and construction practices vary by 

seismicity region, with little or no seismic design 

requirements in low seismicity regions, moderate 

seismic design requirements in moderate seismicity 

regions, and extensive seismic design requirements in 

high seismicity regions. The requirements also vary 

with time, and are routinely updated to reflect new 

knowledge about building seismic performance. 

1.3 Companion FEMA 155 Report 

A companion volume to this report, Rapid Visual 

Screening of Buildings for Potential Seismic 

Hazards: Supporting Documentation (second 

edition) (FEMA 155) documents the technical 

basis for the RVS procedure described in this 

Handbook, including the method for calculating 

the Basic Structural Scores and Score Modifiers. 

The FEMA 155 report (ATC, 2002) also 

summarizes other information considered during 

development of this Handbook, including the 

efforts to solicit user feedback and a FEMA 154 

Users Workshop held in September 2000. The 

FEMA 155 document is available from FEMA by 

Figure 1-2 Data Collection Forms for the three designated 

seismicity regions (low, moderate, and high). 
4 1: Introduction FEMA 154 

dialing 1-800-480-2520 and should be consulted 

for any needed or desired supporting 

documentation. 

1.4 Relationship of FEMA 154 to 

Other Documents in the FEMA 

Existing Building Series 

The FEMA 154 Handbook has been developed as 

an integral and fundamental part of the FEMA 

report series on seismic safety of existing 

buildings. It is intended for use by design 

professionals and others to mitigate the damaging 

effects of earthquakes on existing buildings. The 

series includes: 

• FEMA 154 (this handbook), which provides a 

procedure that can be rapidly implemented to 

identify buildings that are potentially 

seismically hazardous. 

• FEMA 310, Handbook for Seismic Evaluation 

of Buildings—A Prestandard (ASCE, 1998), 

which provides a procedure to inspect in detail 

a given building to evaluate its seismic 

resisting capacity (an updated version of the 

FEMA 178 NEHRP Handbook for the Seismic 

Evaluation of Existing Buildings [BSSC, 

1992]). The FEMA 310 Handbook is ideally 

suited for use on those buildings identified by 

the FEMA 154 RVS procedure as potentially 

hazardous. 

FEMA 310 is expected to be superseded in 

2002 by ASCE 31, a standard of the American 

Society of Civil Engineers approved by the 

American National Standards Institute 

(ANSI). References in this Handbook to 

FEMA 310 should then refer to ASCE 31. 

• FEMA 356, Prestandard and Commentary for 

the Seismic Rehabilitation of Buildings

(ASCE, 2000), which provides recommended 

procedures for the seismic rehabilitation of 

buildings with inadequate seismic capacity, as 

determined, for example, by a FEMA 310 (or 

FEMA 178) evaluation. The FEMA 356 

Prestandard is based on the guidance provided 

in the FEMA 273 NEHRP Guidelines for the 

Seismic Rehabilitation of Buildings (ATC, 

1997a), and companion FEMA 274 

Commentary on the NEHRP Guidelines for 

the Seismic Rehabilitation of Buildings (ATC, 

1997b). 

1.5 Uses of RVS Survey Results 

While the principal purpose of the RVS procedure 

is to identify potentially seismically hazardous 

buildings needing further evaluation, results from 

RVS surveys can also be used for other purposes. 

These include: (1) ranking a community’s (or 

agency’s) seismic rehabilitation needs; (2) 

designing seismic hazard mitigation programs for 

a community (or agency); (3) developing 

inventories of buildings for use in regional 

earthquake damage and loss impact assessments; 

(4) planning postearthquake building safety 

evaluation efforts; and (5) developing buildingspecific seismic vulnerability information for 

purposes such as insurance rating, decision 

making during building ownership transfers, and 

possible triggering of remodeling requirements 

during the permitting process. Additional 

discussion on the use of RVS survey results is 

provided in Chapter 4. 

1.6 How to Use this Handbook 

The Handbook has been designed to facilitate the 

planning and execution of rapid visual screening. 

It is assumed that the RVS authority has already 

decided to conduct the survey, and that detailed 

guidance is needed for all aspects of the surveying 

process. Therefore, the main body of the 

Handbook focuses on the three principal activities 

in the RVS: planning, execution, and data 

interpretation. Chapter 2 contains detailed 

information on planning and managing an RVS. 

Chapter 3 describes in detail how the Data 

Collection Form should be completed, and 

Chapter 4 provides guidance on interpreting and 

using the results from the RVS. Finally, Chapter 5 

provides several example applications of the RVS 

procedure on real buildings. 

Relevant seismic hazard maps, full-sized Data 

Collection Forms, including a Quick Reference 

Guide for RVS implementation, guidance for 

reviewing design and construction drawings, and 

additional guidance for identifying a building’s 

seismic lateral-load-resisting system from the 

street are provided in Appendices A, B, C, and D, 

respectively. Appendix E provides additional 

information on the building types considered in 

the RVS procedure, and Appendix F provides an 

overview of earthquake fundamentals, the 

seismicity of the United States, and earthquake 

effects. 
FEMA 154 2: Planning and Managing Rapid Visual Screening 5 

Chapter 2 

Planning and Managing 

Rapid Visual Screening 

Once the decision to conduct rapid visual 

screening (RVS) for a community or group of 

buildings has been made by the RVS authority, the 

screening effort can be expedited by pre-planning 

and careful overall management of the 

process. This chapter describes the overall 

screening implementation sequence and 

provides detailed information on important 

pre-planning and management aspects. 

Instructions on how to complete the Data 

Collection Form are provided in Chapter 3. 

2.1 Screening Implementation 

Sequence 

There are several steps involved in 

planning and performing an RVS of 

potentially seismically hazardous buildings. 

As a first step, if it is to be a public or 

community project, the local governing 

body and local building officials should 

formally approve of the general procedure. 

Second, the public or the members of the 

community should be informed about the 

purpose of the screening process and how it 

will be carried out. There are also other 

decisions to be made, such as use of the 

screening results, responsibilities of the 

building owners and the community, and 

actions to be taken. Some of these 

decisions are specific to each community 

and therefore are not discussed in this 

Handbook. 

The general sequence of implementing 

the RVS procedure is depicted in Figure 

2-1. The implementation sequence 

includes: 

• Budget development and cost 

estimation, recognizing the expected 

extent of the screening and further use 

of the gathered data; 

• Pre-field planning, including selection 

of the area to be surveyed, 

identification of building types to be 

screened, selection and development of a 

record-keeping system, and compilation and 

development of maps that document local 

seismic hazard information; 

Figure 2-1 Rapid visual screening implementation sequence. 

Pre-plan field survey and 

identify the area to be 

screened 

Acquire and review 

pre-field data, 

including existing 

building files, 

databases, and soil 

types for the 

surveyed area

Choose your screeners, train

them and make assignments

If you have access

to the interior, verify

construction type

and plan

irregularities

Review existing

construction

drawings, if

available to verify

age, size,

construction type,

and irregularities

Photograph the building with

instant or digital camera

Screen the building

from the exterior on

all available sides;

sketch the plan and

elevation

Select and review 

Data Collection 

Form

Develop budget

and cost estimate

Check for

quality and 

file the field 

data in the 

record keeping 

system 
6 2: Planning and Managing Rapid Visual Screening FEMA 154

• Selection and review of the Data Collection 

Form; 

• Selection and training of screening personnel; 

• Acquisition and review of pre-field data; 

including review of existing building files and 

databases to document information identifying 

buildings to be screened (e.g., address, lot 

number, number of stories, design date) and 

identifying soil types for the survey area; 

• Review of existing building plans, if available; 

• Field screening of individual buildings (see 

Chapter 3 for details), which consists of: 

1. Verifying and updating building 

identification information, 

2. Walking around the building and 

sketching a plan and elevation view on the 

Data Collection Form, 

3. Determining occupancy (that is, the 

building use and number of occupants), 

4. Determining soil type, if not identified 

during the pre-planning process, 

5. Identifying potential nonstructural falling 

hazards, 

6. Identifying the seismic-lateral-loadresisting system (entering the building, if 

possible, to facilitate this process) and 

circling the Basic Structural Hazard Score 

on the Data Collection Form, 

7. Identifying and circling the appropriate 

seismic performance attribute Score 

Modifiers (e.g., number of stories, design 

date, and soil type) on the Data Collection 

Form, 

8. Determining the Final Score, S (by 

adjusting the Basic Structural Hazard 

Score with the Score Modifiers identified 

in Step 7), and deciding if a detailed 

evaluation is required, and 

9. Photographing the building; and 

• Checking the quality and filing the screening 

data in the record-keeping system, or database. 

2.2 Budget Development and Cost 

Estimation 

Many of the decisions that are made about the 

level of detail documented during the rapid visual 

screening procedure will depend upon budget 

constraints. Although the RVS procedure is 

designed so field screening of each building 

should take no more than 15 to 30 minutes (30 

minutes to one hour if access to the interior is 

obtained), time and funds should also be allocated 

for pre-field data collection. Pre-field data 

collection can be time consuming (10 to 30 

minutes per building depending on the type of 

supplemental data available). However, it can be 

extremely useful in reducing the total field time 

and can increase the reliability of data collected in 

the field. A good example of this is the age, or 

design date, of a building. This might be readily 

available from building department files but is 

much more difficult to estimate from the street. 

Another issue to consider is travel time, if the 

distance between buildings to be screened is large. 

Because pre-field data collection and travel time 

could be a significant factor in budget allocations, 

it should be considered in the planning phase. 

Other factors that should be considered in cost 

estimation are training of personnel and the 

development and administration of a recordkeeping system for the screening process. The 

type of record keeping system selected will be a 

function of existing procedures and available 

funds as well as the ultimate goal of the screening. 

For example, if the screening is to be used solely 

for potential seismic damage estimation purposes, 

administrative costs will be different from those of 

a screening in which owners of low-scoring 

buildings must subsequently be notified, and 

compliance with ordinances is required. 

2.3 Pre-Field Planning 

The RVS authority may decide due to budget, time 

or other types of constraints, that priorities should 

be set and certain areas within the region should 

be surveyed immediately, whereas other areas can 

be surveyed at a later time because they are 

assumed to be less hazardous. An area may be 

selected because it is older and may have a higher 

density of potentially seismically hazardous 

buildings relative to other areas. For example an 

older part of the RVS authority region that consists 

mainly of commercial unreinforced masonry 

buildings may be of higher priority than a newer 

area with mostly warehouse facilities, or a 

residential section of a city consisting of woodframe single-family dwellings. 

Compiling and developing maps for the 

surveyed region is important in the initial planning 

phase as well as in scheduling of screeners. Maps 

of soil profiles, although limited, will be directly 

useful in the screening, and maps of landslide 

potential, liquefaction potential, and active faults 
FEMA 154 2: Planning and Managing Rapid Visual Screening 7 

provide useful background information about the 

relative hazard in different areas. Maps of lots 

will be useful in scheduling screeners and, as data 

are collected, in identifying areas with large 

numbers of potentially hazardous buildings. 

Another important phase of pre-field planning 

is interaction with the local design profession and 

building officials. Discussions should include 

verification of when certain aspects of seismic 

design and detailing were adopted and enforced. 

This will be used in adjusting the scoring system 

for local practices and specifying benchmark 

years. 

The record-keeping system will vary among 

RVS authorities, depending on needs, goals, 

budgets and other constraints, and may in fact 

consist of several systems. Part of this planning 

phase may include deciding how buildings are to 

be identified. Some suggestions are street address, 

assessor’s parcel number, census tract, and lot 

number or owner. Consideration should be given 

to developing a computerized database containing 

location and other building information, which 

could easily be used to generate peel-off labels 

for the Data Collection Form, or to generate 

forms that incorporate unique information for 

each building. 

The advantage of using a computerized 

record generation and collection system is that 

graphical data, such as sketches and 

photographs, are increasingly more easily 

converted to digital form and stored on the 

computer, especially if they are collected in 

digital format in the field. This can be 

facilitated through the use of personal digital 

assistants (PDAs), which would require the 

development of a FEMA 154 application, and 

the use of digital cameras. 

If a computerized database is not used, 

microfilm is a good storage medium for 

original hard copy, because photographs, 

building plans, screening forms and subsequent 

follow-up documentation can be kept together 

and easily copied. Another method that has 

been used is to generate a separate hard-copy 

file for each building as it is screened. In fact, 

the screening form can be reproduced on a 

large envelope and all supporting material and 

photographs stored inside. This solves any 

problems associated with attaching multiple 

sketches and photographs, but the files grow 

rapidly and may become unmanageable. 

2.4 Selection and Review of the 

Data Collection Form 

There are three Data Collection Forms, one for 

each of the following three regions of seismicity: 

low (L), moderate (M), and high (H). Full-sized 

versions of each form are provided in Appendix B, 

along with a Quick Reference Guide that contains 

definitions and explanations for terms used on the 

Data Collection Form. Each Data Collection Form 

(see example, Figure 2-2) provides space to 

record the building identification information, 

draw a sketch of the building (plan and 

elevation views), attach a photograph of the 

building, indicate the occupancy, indicate the soil 

type, document the existence of falling hazards, 

develop a Final Structural Score, S, for the 

building, indicate if a detailed evaluation is 

required, and provide additional comments. The 

structural scoring system consists of a matrix of 

Basic Structural Hazard Scores (one for each 

building type and its associated seismic lateralforce-resisting system) and Score Modifiers to 

Figure 2-2 Example RVS Data Collection Form (high 

seismicity). 
8 2: Planning and Managing Rapid Visual Screening FEMA 154

account for observed attributes that modify 

seismic performance. The Basic Structural Hazard 

Scores and Score Modifiers are based on (1) 

design and construction practices in the region, (2) 

attributes known to decrease or increase seismic 

resistance capacity, and (3) maximum considered 

ground motions for the seismicity region under 

consideration. The Basic Structural Hazard Score, 

Score Modifiers, and Final Structural Score, S, all 

relate to the probability of building collapse, 

should the maximum ground motions considered 

by the RVS procedure occur at the site. Final S

scores typically range from 0 to 7, with higher S

scores corresponding to better seismic 

performance. 

The maximum ground motions considered in 

the scoring system of the RVS procedure are 

consistent with those specified for detailed 

building seismic evaluation in the FEMA 310 

Report, Handbook for the Seismic Evaluation of 

Buildings—A Prestandard. Such ground motions 

generally have a 2% chance of being exceeded in 

50 years, and are multiplied by a 2/3 factor in the 

FEMA 310 evaluation procedures and in the 

design requirements for new buildings in FEMA 

302, Recommended Provisions for Seismic 

Regulations for New Buildings and Other 

Structures (BSSC, 1997). (Ground motions having 

a 2% probability of being exceeded in 50 years are 

commonly referred to as the maximum considered 

earthquake (MCE) ground motions.) 

2.4.1 Determination of Seismicity Region 

To select the appropriate Data Collection Form, 

it is first necessary to determine the seismicity 

region in which the area to be screened is located. 

The seismicity region (H, M, or L) for the screening 

area can be determined by one of two methods: 

1. Find the location of the surveyed region on the 

seismicity map of Figure 1-1, or one of the 

enlarged seismicity maps provided in Appendix 

A, and identify the corresponding seismicity 

region, or; 

2. Access the U.S. Geological Survey web page 

(http://geohazards.cr.usgs.gov/eq/), select 

“Hazard by Zip Code” or “Hazard by Lat/Long” 

under the “Seismic Hazard” heading, enter the 

appropriate values of zip code or latitude and 

longitude, select the spectral acceleration value 

(SA) for a period of 0.2 seconds and the SA 

value for a period of 1.0 second, multiply the SA 

values by 2/3, and use the criteria of Table 2-1 to 

select the appropriate seismicity region, 

assuming that the highest seismicity level 

defined by the parameters in Table 2-1 shall 

govern. 

Use more recent additions of these maps when 

they become available. 

The web site approach of Method 2, which uses 

seismicity region definitions used in other recently 

developed FEMA documents, is preferred as it 

enables the user to determine seismicity based on a 

more precisely specified location. In contrast, each 

county shown in Figure 1-1 is assigned its seismicity 

on the basis of the highest seismicity in that county, 

even though it may only apply to a small portion of 

the county. 

Table 2-1 Regions of Seismicity with 

Corresponding Spectral Acceleration 

Response (from FEMA 310) 

Region of 

Seismicity

Spectral Acceleration 

Response, SA (shortperiod, or 0.2 sec)

Spectral Acceleration 

Response, SA (longperiod or 1.0 sec)

Low less than 0.167 g (in 

horizontal direction)

less than 0.067 g (in 

horizontal direction)

Moderate greater than or equal 

to 0.167 g but less 

than 0.500 g (in 

horizontal direction) 

greater than or equal 

to 0.067 g but less 

than 0.200 g (in 

horizontal direction) 

High greater than or equal 

to 0.500 g (in 

horizontal direction) 

greater than or equal 

to 0.200 g (in 

horizontal direction) 

Notes: g = acceleration of gravity 

2.4.2 Determination of Key Seismic Code 

Adoption Dates and Other 

Considerations 

The Data Collection Form is meant to be a 

model that may be adopted and used as it is 

presented in this Handbook. The form may also be 

modified according to the needs of the RVS 

authority. Therefore, another aspect of the 

screening planning process is to review the Data 

Collection Form to determine if all required data 

are represented or if modifications should be made 

to reflect the needs and special circumstances of 

the authority. For example, an RVS authority may 

choose to define additional occupancy classes such 

as “parking structure” or “multi-family 

residential.” 

One of the key issues that must be addressed 

in the planning process is the determination of (1) 

the year in which seismic codes were initially
FEMA 154 2: Planning and Managing Rapid Visual Screening 9 

Table 2-2. Benchmark Years for RVS Procedure Building Types (based on FEMA 310) 

Model Building Seismic Design Provisions

Building Type BOCA SBCC UBC NEHRP

W1: Light wood-frame residential and commercial buildings 

smaller than or equal to 5,000 square feet 1992 1993 1976 1985 

W2: Light wood-frame buildings larger than 5,000 square 

feet 1992 1993 1976 1985 

S1: Steel moment-resisting frame buildings ** ** 1994 ** 

S2: Braced steel frame buildings 1992 1993 1988 1991 

S3: Light metal buildings * * * * 

S4: Steel frame buildings with cast-in-place concrete shear 

walls 1992 1993 1976 1985 

S5: Steel frame buildings with unreinforced masonry infill 

walls * * * * 

C1: Concrete moment-resisting frame buildings 1992 1993 1976 1985 

C2: Concrete shear-wall buildings 1992 1993 1976 1985 

C3: Concrete frame buildings with unreinforced masonry 

infill walls * * * * 

PC1: Tilt-up buildings * * 1997 * 

PC2: Precast concrete frame buildings * * * * 

RM1: Reinforced masonry buildings with flexible floor and 

roof diaphragms * * 1997 * 

RM2: Reinforced masonry buildings with rigid floor and roof 

diaphragms 1992 1993 1976 1985 

URM: Unreinforced masonry bearing-wall buildings * * 1991 * 

*No benchmark year; **contact local building department for benchmark year. 

BOCA: Building Officials and Code Administrators, National Building Code 

SBCC: Southern Building Code Congress, Standard Building Code.

UBC: International Conference of Building Officials, Uniform Building Code

NEHRP: National Earthquake Hazard Reduction Program, FEMA 302 Recommended Provisions for the Development of Seismic 

Regulations for New Buildings

adopted and enforced by the local jurisdiction, and 

(2) the year in which significantly improved 

seismic codes were adopted and enforced (this 

latter year is known as the benchmark year). In 

high and moderate seismicity regions, the Basic 

Structural Hazard Scores for the various building 

types are calculated for buildings built after the 

initial adoption of seismic codes, but before 

substantially improved codes were adopted. For 

these regions, Score Modifiers designated as “Pre 

Code” and “Post Benchmark” are provided, 

respectively, for buildings built before the 

adoption of codes and for buildings built after the 

adoption of substantially improved codes. In low 

seismicity regions, the Basic Structural Hazard 

Scores are calculated for buildings built before the 

initial adoption of seismic codes. For buildings in 

these regions, the Score Modifier designated as 

“Pre Code” is not applicable (N/A), and the Score 

Modifier designated as “Post Benchmark” is 

applicable for buildings built after the adoption of 

seismic codes. 

Therefore, as part of this review process, the 

RVS authority should identify (1) the year in 

which seismic codes were first adopted and 

enforced in the area to be screened, (2) the 

“benchmark” year in which significantly improved 

seismic code requirements were adopted for each 

building type considered by the RVS procedure 

(see Table 2-2), and (3) the year in which the 

community adopted seismic anchorage 

requirements for heavy cladding. If the RVS 

authority in high and moderate seismicity regions 

is unsure of the year(s) in which codes were 

initially adopted, the default year for all but one 

building type is 1941 (the default year specified in 

the HAZUS criteria; NIBS, 1999). The one 

exception is PC1 (tilt-up) buildings, for which it is 

assumed that seismic codes were initially adopted 

in 1973, the year in which wall-diaphragm (ledger) 

connection requirements first appeared in the 

Uniform Building Code (ICBO, 1973). 

During the review of the Data Collection 

Form, the RVS authority should confer with the 
10 2: Planning and Managing Rapid Visual Screening FEMA 154

1. Model Building Types and Critical Code Adoption 

and Enforcement Dates Year Seismic Codes Benchmark 

 Initially Adopted Year When 

Structure Types and Enforced* Codes Improved

W1 Light wood frame, residential or commercial, < 5000 square feet _______ _______ 

W2 Wood frame buildings, > 5000 square feet _______ _______ 

S1 Steel moment-resisting frame _______ _______ 

S2 Steel braced frame _______ _______ 

S3 Light metal frame _______ _______ 

S4 Steel frame with cast-in-place concrete shear walls _______ _______ 

S5 Steel frame with unreinforced masonry infill _______ _______ 

C1 Concrete moment-resisting frame _______ _______ 

C2 Concrete shear wall _______ _______ 

C3 Concrete frame with unreinforced masonry infill _______ _______ 

PC1 Tilt-up construction _______ _______ 

PC2 Precast concrete frame _______ _______ 

RM1 Reinforced masonry with flexible floor and roof diaphragms _______ _______ 

RM2 Reinforced masonry with rigid diaphragms _______ _______ 

URM Unreinforced masonry bearing-wall buildings _______ _______

*Not applicable in regions of low seismicity

2. Anchorage of Heavy Cladding 

Year in which seismic anchorage requirements were adopted: _______

chief building official, plan checkers, and other 

design professionals experienced in seismic design 

to identify the years in which the affected 

jurisdiction initially adopted and enforced seismic 

codes (if ever) for the building lateral-forceresisting structural systems considered by the RVS 

procedure. Since municipal codes are generally 

adopted by the city council, another source for this 

information, in many municipalities, is the city 

clerk’s office. In addition to determining the year 

in which seismic codes were initially adopted and 

enforced, the RVS authority should also determine 

(1) the benchmark years in which substantially 

improved seismic codes were adopted and 

enforced for the various lateral-load-resisting 

systems and (2) the year in which anchorage 

requirements for cladding were adopted and 

enforced. These dates should be inserted on the 

Quick Reference Guide (Appendix B) that has 

been created to facilitate the use of the Data 

Collection Form (see Figure 2-3). 

During the Data Collection Form review 

process, it is critically important that the Basic 

Structural Hazard Scores and Score Modifiers, 

which are described in detail in Chapter 3, not be 

changed without input from professional engineers 

familiar with earthquake-resistant design and 

construction practices of the local community. A 

checklist of issues to be considered when 

reviewing the Data Collection Form is provided in 

Table 2-3. 

Table 2-3 Checklist of Issues to be Considered 

During Pre-Field Work Review of the 

Data Collection Form 

 Evaluate completeness of occupancy categories 

and appropriateness of occupancy loads 

 Determine year in which seismic codes were 

initially adopted in the jurisdiction 

 Determine “benchmark” years in which the 

jurisdiction adopted and enforced significantly 

improved seismic codes for the various building 

types considered by the RVS procedure 

 Determine year in which the jurisdiction 

adopted and enforced anchorage requirements 

for heavy cladding 

2.4.3 Determination of Cut-Off Score 

Use of the RVS on a community-wide basis 

enables the RVS authority to divide screened 

buildings into two categories: those that are 

expected to have acceptable seismic performance, 

and those that may be seismically hazardous and 

Figure 2-3 Sections 1 and 2 of Quick Reference Guide (for use with Data Collection Form).
FEMA 154 2: Planning and Managing Rapid Visual Screening 11 

should be studied further. This requires that the 

RVS authority determine, preferably as part of the 

pre-planning process, an appropriate “cut-off” 

score. 

An S score of 2 is suggested as a “cut-off”, 

based on present seismic design criteria. Using 

this cut-off level, buildings having an S score of 2 

or less should be investigated by a design 

professional experienced in seismic design (see 

Section 3.9, 4.1 and 4.2 for additional information 

on this issue). 

2.5 Qualifications and Training for 

Screeners 

It is anticipated that a training program will be 

required to ensure a consistent, high quality of the 

data and uniformity of decisions among screeners. 

Training should include discussions of lateralforce-resisting systems and how they behave when 

subjected to seismic loads, hw to use the Data 

Collection Form, what to look for in the field, and 

how to account for uncertainty. In conjunction 

with a professional engineer experienced in 

seismic design, screeners should simultaneously 

consider and score buildings of several different 

types and compare results. This will serve as a 

“calibration” for the screeners. 

This process can easily be accomplished in a 

classroom setting with photographs of actual 

buildings to use as examples. Prospective 

screeners review the photographs and perform the 

RVS procedure as though they were on the 

sidewalk. Upon completion, the class discusses 

the results and students can compare how they did 

in relation to the rest of the class. 

2.6 Acquisition and Review of PreField Data 

Information on the structural system, age or 

occupancy (that is, use) may be available from 

supplemental sources. These data, from assessor 

and building department files, insurance (Sanborn) 

maps, and previous studies, should be reviewed 

and collated for a given area before commencing 

the field survey for that area. It is recommended 

that this supplemental information either be 

written directly on the Data Collection Forms as it 

is retrieved or be entered into a computerized 

database. The advantage of a database is that 

selected information can be printed in a report 

format that can be taken into the field, or printed 

onto peel-off labels that can be affixed to the Data 

Collection Form (see Figure 2-4). In addition, 

screening data can be added to the databases and 

used to generate maps and reports. Some sources 

of supplemental information are described in 

Sections 2.6.1 through 2.6.5. 

2.6.1 Assessor’s Files 

Although assessor’s files may contain information 

about the age of the building, the floor area and 

the number of stories, most information relates to 

ownership and assessed value of the land and 

improvements, and thus is of relatively little value 

for RVS purposes. The construction type 

indicated is often incorrect and in most cases 

should not be used. In addition, the age of a 

building retrieved from assessor’s files may not, 

and most likely is not, the year that the structure 

was built. Usually assessor’s files contain the year 

that the building was first eligible for taxation. 

Because the criteria for this may vary, the date 

may be several years after the building was 

designed or constructed. If no other source of 

information is available this will give a good 

estimate of the period during which the building 

Figure 2-4 Building identification portion of RVS

Data Collection Form. 
12 2: Planning and Managing Rapid Visual Screening FEMA 154

was constructed. However, this date should not be 

used to establish conclusively the code under 

which the a building was designed. Assessor’s 

offices may have parcel or lot maps, which may be 

useful for locating sites or may be used as a 

template for sketching building adjacencies on a 

particular city block. 

2.6.2 Building Department Files 

The extent and completeness of information in 

building department files will vary from 

jurisdiction to jurisdiction. For example, in some 

locations all old files have been removed or 

destroyed, so there is no information on older 

buildings. In general, files (or microfilm) may 

contain permits, plans and structural calculations 

required by the city. 

Sometimes there is 

occupancy and use 

information, but little 

information about 

structural type will be 

found except from the 

review of plans or 

calculations. 

2.6.3 Sanborn Maps 

These maps, published 

primarily for the 

insurance industry since 

the late 1800s, exist for 

about 22,000 

communities in the 

United States. The 

Sanborn Map Company 

stopped routinely 

updating these maps in 

the early 1960s, and many 

communities have not 

kept these maps up-todate. Thus they may not 

be useful for newer 

construction. However, 

the maps may contain 

useful data for older 

construction. They can be 

found at the library or in 

some cases in building 

department offices. Figure 

2-5 provides an example 

of an up-to-date Sanborn 

map Figure 2-6 shows a 

key to identifiers on 

Sanborn maps. 

Information found on a Sanborn map includes: 

• height of building, 

• number of stories, 

• year built, 

• thickness of walls, 

• building size (square feet), 

• type of roof (tile, shingle, composite), 

• building use (dwelling, store, apartment), 

• presence of garage under structure, and 

• structural type (wood frame, fireproof 

construction, adobe, stone, concrete). 

Figure 2-5 Example Sanborn map showing building information for a city block. 
FEMA 154 2: Planning and Managing Rapid Visual Screening 13 

Parcel maps are also available and contain lot 

dimensions. If building size information cannot be 

obtained from another source such as the 

assessor’s file, the parcel maps are particularly 

helpful for determining building dimensions in 

urban areas where buildings cover the entire lot. 

However, even if the building does not cover the 

entire lot, it will be easier to estimate building 

dimensions if the lot dimensions are known. 

Figures 2-7 and 2-8 show a Sanborn map and 

photographs of a city block. Building descriptions 

obtained from the Sanborn maps are also included. 

Figure 2-6 Key to Sanborn map symbols. Also, see the Internet, www.sanbornmap.com. 
14 2: Planning and Managing Rapid Visual Screening FEMA 154

1. 10 story commercial office 

2. 3 story commercial, built 1913 

3. 2 story commercial 

4. 3 story commercial, reinforced concrete frame, built 1906 

5. 7 story commercial office, reinforced concrete frame, built 1923 

6. 2 story commercial, reinforced concrete 

7. 5 story commercial office, reinforced concrete 

8. 20 story commercial office, steel frame with reinforced concrete, built 1914 

9. 4 story commercial, built 1966 

10. 40 story commercial office, built 1965-66, concrete and glass exterior 

Figure 2-7 Sanborn map and corresponding aerial photograph of a city block. 
FEMA 154 2: Planning and Managing Rapid Visual Screening 15 

Although the information on 

Sanborn maps may be useful, 

it is the responsibility of the 

screener to verify it in the 

field. 

2.6.4 Municipal 

Databases 

With the widespread use of 

the internet, many 

jurisdictions are creating “online” electronic databases for 

use by the general public. 

These databases provide 

general information on the 

various building sites within 

the jurisdiction. These 

databases are not detailed 

enough at this point in time to 

provide specific information 

about the buildings; they do, 

however, provide some good 

demographic information that 

could be of use. As the 

municipalities develop more 

comprehensive information, 

these databases will become 

more useful to the RVS 

screening. Figure 2-9 shows 

examples of the databases 

from two municipalities in the 

United States. 

2.6.5 Previous Studies

In a few cases, previous 

building inventories or studies 

of hazardous buildings or 

hazardous nonstructural elements (e.g., 

parapets) may have been 

performed. These studies may be limited to a 

particular structural or occupancy class, but they 

may contain useful maps or other relevant 

structural information and should be reviewed. 

Other important studies might address related 

seismic hazard issues such as liquefaction or 

landslide potential. Local historical societies may 

have published books or reports about older 

buildings in the community. Fire departments are 

often aware of the overall condition and 

composition of building interiors. 

2.6.6 Soils Information 

Soil type has a major influence on amplitude and 

duration of shaking, and thus structural damage. 

Generally speaking, the deeper the soils at a site, the 

more damaging the earthquake motion will be. The 

six soil types considered in the RVS procedure are 

the same as those specified in the FEMA 302 report, 

NEHRP Recommended Provisions for the Seismic 

Design of New Buildings and Other Structures

(BSSC, 1997): hard rock (type A); average rock 

(type B); dense soil (type C), stiff soil (type D); soft 

soil (type E), and poor soil (type F). Additional 

information on these soil types and how to identify 

Figure 2-8 Photographs of elevation views of buildings shown in Figure 2-7. 
16 2: Planning and Managing Rapid Visual Screening FEMA 154

City of Oakland, California 

Mecklenburg County, North Carolina 

Figure 2-9 Examples of in-house screen displays of municipal databases.
FEMA 154 2: Planning and Managing Rapid Visual Screening 17 

them are provided in the side bar. Buildings on 

soil type F cannot be screened effectively by the 

RVS procedure, other than to recommend that 

buildings on this soil type be further evaluated by 

a geotechnical engineer and design professional 

experienced in seismic design. 

Since soil conditions cannot be readily 

identified by visual methods in the field, geologic 

and geotechnical maps and other information 

should be collected during the planning stage and 

put into a readily usable map format for use during 

RVS. During the screening, or the planning stage, 

this soil type should also be documented on the 

Data Collection Form by circling the correct soil 

type, as designated by the letters A through F, (see 

Figure 2-10). If sufficient guidance or data are not 

available during the planning stage to classify the 

soil type as A through E, a soil type E should be 

assumed. However, for one-story or two-story 

buildings with a roof height equal to or less than 

25 feet, a class D soil type may be assumed when 

site conditions are not known. (See the note in 

preceding paragraph regarding soil type F.) 

2.7 Review of Construction 

Documents 

Whenever possible, design and construction 

documents should be reviewed prior to the 

conduct of field work to help the screener identify 

the type of lateral-force- resisting system for each 

building. The review of construction documents 

to identify the building type substantially improves 

the confidence in this determination. As described 

in Section 3.7, the RVS procedure requires that 

each building be identified as one of 15 model 

building types2

. Guidance for reviewing design 

and construction drawings is provided in 

Appendix C. 

 

2

The 15 model building types used in FEMA 154 are an 

abbreviated list of the 22 types now considered standard 

by FEMA; excluded from the FEMA 154 list are subclassifications of certain framing types that specify that 

the roof and floor diaphragms are either rigid or 

flexible. 

Soil Type Definitions and Related Parameters 

The six soil types, with measurable parameters that 

define each type, are: 

Type A (hard rock): measured shear wave velocity, vs

> 5000 ft/sec.

Type B (rock): vs between 2500 and 5000 ft/sec. 

Type C (soft rock and very dense soil): vs between 

1200 and 2500 ft/sec, or standard blow count N > 50, or 

undrained shear strength su > 2000 psf. 

Type D (stiff soil): vs between 600 and 1200 ft/sec, or 

standard blow count N between 15 and 50, or undrained 

shear strength, su between 1000 and 2000 psf. 

Type E (soft soil): More than 100 feet of soft soil with 

plasticity index PI > 20, water content w > 40%, and 

su < 500 psf; or a soil with vs ≤ 600 ft/sec. 

Type F (poor soil): Soils requiring site-specific 

evaluations: 

• Soils vulnerable to potential failure or collapse 

under seismic loading, such as liquefiable soils, 

quick and highly-sensitive clays, collapsible 

weakly-cemented soils. 

• Peats or highly organic clays (H > 10 feet of peat 

or highly organic clay, where H = thickness of 

soil.). 

• Very high plasticity clays (H > 25 feet with 

PI > 75). 

• More than 120 ft of soft or medium stiff clays. 

The parameters vs, N, and su are, respectively, the 

average values (often shown with a bar above) of shear 

wave velocity, Standard Penetration Test (SPT) blow 

count and undrained shear strength of the upper 100 

feet of soils at the site. 

Figure 2-10 Location on Data Collection Form 

where soil type information is 

recorded. 
18 2: Planning and Managing Rapid Visual Screening FEMA 154

2.8 Field Screening of Buildings 

RVS screening of buildings in the field should be 

carried out by teams consisting of two individuals. 

Teams of two are recommended to provide an 

opportunity to discuss issues requiring judgment 

and to facilitate the data collection process. If at 

all possible, one of the team members should be a 

design professional who can identify lateral-forceresisting systems. 

Relatively few tools or equipment are needed. 

Table 2-4 contains a checklist of items that may be 

needed in performing an RVS as described in this 

Handbook.

2.9 Checking the Quality and Filing 

the Field Data in the RecordKeeping System 

The last step in the implementation of rapid visual 

screening is checking the quality and filing the 

RVS data in the record-keeping system established 

for this purpose. If the data are to be stored in file 

folders or envelopes containing data for each 

building that was screened, or on microfilm, the 

process is straightforward, and requires careful 

organization. If the data are to be stored in digital 

form, it is important that the data input and 

verification process include either double entry of 

all data, or systematic in-depth review of print outs 

(item by item review) of all entered data. 

It is also recommended that the quality review 

be performed under the oversight of a design 

professional with significant experience in seismic 

design. 

Table 2-4 Checklist of Field Equipment 

Needed for Rapid Visual Screening 

 Binoculars, if high-rise buildings are to be 

evaluated 

 Camera, preferably instant or digital 

 Clipboard for holding Data Collection Forms 

 Copy of the FEMA 154 Handbook

 Laminated version of the Quick Reference Guide 

defining terms used on the Data Collection Form 

(see Appendix B) 

 Pen or pencil 

 Straight edge (optional for drawing sketches) 

 Tape or stapler, for affixing photo if instant 

camera is used 
FEMA 154 3: Completing the Data Collection Form 19 

Chapter 3 

Completing the 

Data Collection Form 

3.1 Introduction 

This chapter provides instructions on how to 

complete the Data Collection Form (Figure 

3-1). It is assumed that the Data Collection 

Form has already been selected, based on the 

seismicity level of the area to be screened (as 

per Chapter 2). The Data Collection Form is 

completed for each building screened through 

execution of the following steps: 

1. Verifying and updating the building 

identification information; 

2. Walking around the building to identify its 

size and shape, and sketching a plan and 

elevation view on the Data Collection 

Form; 

3. Determining and documenting occupancy; 

4. Determining soil type, if not identified 

during the pre-planning process; 

5. Identifying potential nonstructural falling 

hazards, if any, and indicating their 

existence on the Data Collection Form; 

6. Identifying the seismic lateral-load 

resisting system (entering the building, if 

possible, to facilitate this process) and 

circling the related Basic Structural Hazard 

Score on the Data Collection Form; 

7. Identifying and circling the appropriate 

seismic performance attribute Score 

Modifiers (e.g., number of stories, design 

date, and soil type) on the Data Collection 

Form; 

8. Determining the Final Score, S (by adjusting 

the Basic Structural Hazard Score with the 

Score Modifiers identified in Step 7), and 

deciding if a detailed evaluation is required; 

and 

9. Photographing the building and attaching the 

photo to the form (if an instant camera is 

used), or indicating a photo reference number 

on the form (if a digital camera is used). 

Full-sized copies of the Data Collection Forms 

(one for each seismicity region) are provided in 

Appendix B, along with a Quick Reference Guide 

defining terms used on the Data Collection Form. 

The form has been designed to be filled out in a 

progressive manner, with a minimum of writing 

(most items simply can be circled). 

Following are detailed instructions and 

guidance for each of the nine steps above. 

Figure 3-1 Example RVS Data Collection Form (high seismicity). 
20 3: Completing the Data Collection Form FEMA 154 

3.2 Verifying and Updating the 

Building Identification 

Information 

Space is provided in the upper right-hand portion 

of the Data Collection Form (see Figure 3-2) to 

document building identification information (i.e., 

address, name, number of stories, year built, and 

other data). As indicated in Chapter 2, it is 

desirable to develop and document this 

information during the pre-planning stage, if at all 

possible. This information may be entered 

manually, or be printed on a peel-off label. 

Proper identification and location of the 

building is critically important for subsequent use 

in hazard assessment and mitigation by the RVS 

authority. As described in Chapter 2, the authority 

may prefer to identify and file structures by street 

address, parcel number, building owner, or some 

other scheme. However, it is recommended that as 

a minimum the street address and zip code be 

recorded on the form. Zip code is important 

because it is universal to all municipalities, is an 

especially useful item for later collation and 

summary analyses. Assessor parcel number or lot 

number is also useful for jurisdictional recordkeeping purposes. 

Assuming the identification information is 

provided on a peel-off label, which is then affixed 

to the form, or preprinted directly on the form, 

such information should be verified in the field. If 

the building identification data are not developed 

during the pre-planning stage, it must be 

completed in the field. Documentation of the 

building address information and name, if it exists, 

is straightforward. Following is guidance and 

discussion pertaining to number of stories, year 

built, identification of the screener, and estimation 

of total floor area. 

3.2.1 Number of Stories 

The height of a structure is sometimes related to 

the amount of damage it may sustain. On soft 

soils, a tall building may experience considerably 

stronger and longer duration shaking than a shorter 

building of the same type. The number of stories 

is a good indicator of the height of a building 

(approximately 9-to-10 feet per story for 

residential, 12 feet per story for commercial or 

office). 

Counting the number of stories may not be a 

straightforward issue if the building is constructed 

on a hill or if it has several different roof levels. 

As a general rule, use the largest number (that is, 

count floors from the downhill side to the roof). 

In addition, the number of stories may not be 

unique. A building may be stepped or have a 

tower. Use the comment section and the sketch to 

indicate variations in the number of stories. 

3.2.2 Year Built 

This information is one of the key elements of the 

RVS procedure. Building age is tied directly to 

design and construction practices. Therefore, age 

can be a factor in determining building type and 

thus can affect the final scores. This information 

is not typically available at the site and thus should 

be included in pre-field data collection. 

There may be no single “year built.” Certain 

portions of the structure may have been designed 

and constructed before others. If this should be 

the case, the construction dates for each portion 

can be indicated in the comment section or on the 

sketch (see Section 3.3). Caution should also be 

used when interpreting design practices from date 

of construction. The building may have been 

designed several years before it was constructed 

and thus designed to an earlier code with different 

requirements for seismic detailing. 

If information on “year built” is not available 

during the RVS pre-field data acquisition stage 

(see Section 2.6), a rough estimate of age will be 

made on the basis of architectural style and 

building use. This is discussed in more detail in 

Appendix D, which provides additional guidance 

on determining building attributes from streetside. 

If the year built is only an approximation, an 

asterisk is used to indicate the entry is estimated. 

3.2.3 Screener Identification 

The screener should be identified, by name, 

initials, or some other type of code. At some later 

time it may be important to know who the screener 

was for a particular building, so this information 

should not be omitted. 

Figure 3-2 Portion of Data Collection Form for 

documenting building 

identification. 
FEMA 154 3: Completing the Data Collection Form 21 

3.2.4 Total Floor Area 

The total floor area, in some cases available from 

building department or assessor files (see Section 

2.6), will most likely be estimated by multiplying 

the estimated area of one story by the total number 

of stories in the building. The length and width of 

the building can be paced off or estimated (during 

the planning stage) from Sanborn or other parcel 

maps. Total floor area is useful for estimating 

occupancy load (see Section 3.5.2) and may be 

useful at a later time for estimating the value of the 

building. Indicate with an asterisk when total 

floor area is estimated. 

3.3 Sketching the Plan and 

Elevation Views 

As a minimum, a sketch of the plan of the building 

should be drawn on the Data Collection Form (see 

Figure 3-3). An elevation may also be useful in 

indicating significant features. The sketches are 

especially important, as they reveal many of the 

building’s attributes to the screener as the sketch is 

made. In other words, it forces the screener to 

systematically view all aspects of the building. 

The plan sketch should include the location of the 

building on the site and distance to adjacent 

buildings. One suggestion is to make the plan 

sketch from a Sanborn map as part of pre-field 

work (see Chapter 2), and then verify it in the 

field. This is especially valuable when access 

between buildings is not available. If all sides of 

the building are different, an elevation should be 

sketched for each side. Otherwise indicate that the 

sketch is typical of all sides. The sketch should 

note and emphasize special features such as 

existing significant cracks or configuration 

problems. 

Dimensions should be included. As indicated 

in the previous section, the length and width of the 

building can be paced off or estimated (during the 

planning stage) from Sanborn or other parcel 

maps. 

3.4 Determining Soil Type 

As indicated in Section 2.6.6, soil type should be 

identified and documented on the Data Collection 

Form (see Figure 3-4) during the pre-field soils 

data acquisition and review phase. If soil type has 

not been determined as part of that process, it 

needs to be identified by the screener during the Figure 3-3 Sample Data Collection Form 

showing location for sketches of 

building plan and elevation views. 

SKETCHES 

Figure 3-4 Location on Data Collection Form 

where soil type information is 

documented (circled). 
22 3: Completing the Data Collection Form FEMA 154 

building site visit. If there is no basis for 

classifying the soil type, a soil type E should be 

assumed. However, for one-story or two-story 

buildings with a roof height equal to or less than 

25 feet, a class D soil type may be assumed when 

site conditions are not known. 

3.5 Determining and Documenting 

Occupancy 

Two sets of information are needed relative to 

occupancy: (1) building use, and (2) estimated 

number of persons occupying the building. 

3.5.1 Occupancy 

Occupancy-related information is indicated by 

circling the appropriate information in the leftcenter portion of the form (see Figure 3-5). The 

occupancy of a building refers to its use, whereas 

the occupancy load is the number of people in the 

building (see Section 3.5.2). Although usually not 

bearing directly on the structural hazard or 

probability of sustaining major damage, the 

occupancy of a building is of interest and use 

when determining priorities for mitigation. 

Nine general occupancy classes that are easy 

to recognize have been defined. They are listed on 

the form as Assembly, Commercial, Emergency 

Services (Emer. Services), Government (Govt), 

Historic, Industrial, Office, Residential, School 

buildings. These are the same classes used in the 

first edition of FEMA 154. They have been 

retained in this edition for consistency, they are 

easily identifiable from the street, they generally 

represent the broad spectrum of building uses in 

the United States, and they are similar to the 

occupancy categories in the Uniform Building 

Code (ICBO, 1997). 

The occupancy class that best describes the 

building being evaluated should be circled on the 

form. If there are several types of uses in the 

building, such as commercial and residential, both 

should be circled. The actual use of the building 

may be written in the upper right hand portion of 

the form. For example, one might indicate that 

the building is a post office or a library on the line 

titled “use” in the upper right of the form (see 

Figure 3-2). In both of these cases, one would also 

circle “Govt”. If none of the defined classes seem 

to fit the building, indicate the use in the upper 

right portion of the form (the building 

identification area) or include an explanation in 

the comments section. The nine occupancy 

classes are described below (with general 

indications of occupancy load): 

• Assembly. Places of public assembly are those 

where 300 or more people might be gathered 

in one room at the same time. Examples are 

theaters, auditoriums, community centers, 

performance halls, and churches. (Occupancy 

load varies greatly and can be as much as 1 

person per 10 sq. ft. of floor area, depending 

primarily on the condition of the seating—

fixed versus moveable). 

• Commercial. The commercial occupancy 

class refers to retail and wholesale businesses, 

financial institutions, restaurants, parking 

structures and light warehouses. (Occupancy 

load varies; use 1 person per 50 to 200 sq. ft.). 

• Emergency Services. The emergency services 

class is defined as any facility that would 

likely be needed in a major catastrophe. These 

include police and fire stations, hospitals, and 

communications centers. (Occupancy load is 

typically 1 person per 100 sq. ft.). 

• Government. This class includes local, state 

and federal non-emergency related buildings 

(Occupancy load varies; use 1 person per 100 

to 200 sq. ft.). 

• Historic. This class will vary from community 

to community. It is included because historic 

buildings may be subjected to specific 

ordinances and codes. 
FEMA 154 3: Completing the Data Collection Form 23 

• Industrial. Included in the industrial 

occupancy class are factories, assembly plants, 

large warehouses and heavy manufacturing 

facilities. (Typically, use 1 person per 200 sq. 

ft. except warehouses, which are perhaps 1 

person per 500 sq. ft.). 

• Office. Typical office buildings house clerical 

and management occupancies (use 1 person 

per 100 to 200 sq. ft.). 

• Residential. This occupancy class refers to 

residential buildings such as houses, 

townhouses, dormitories, motels, hotels, 

apartments and condominiums, and residences 

for the aged or disabled. (The number of 

persons for residential occupancies varies 

from about 1 person per 300 sq. ft. of floor 

area in dwellings, to perhaps 1 person per 200 

sq. ft. in hotels and apartments, to 1 per 100 

sq. ft. in dormitories). 

• School. This occupancy class includes all 

public and private educational facilities from 

nursery school to university level. 

(Occupancy load varies; use 1 person per 50 to 

100 sq. ft.). 

When occupancy is used by a community as a 

basis for setting priorities for hazard mitigation 

purposes, the upgrade of emergency services 

buildings is often of highest priority. Some 

communities may have special design criteria 

governing buildings for emergency services. This 

information may be used to add a special Score 

Modifier to increase the score for specially 

designed emergency buildings. 

3.5.2 Occupancy Load 

Like the occupancy class or use of the building, 

the occupancy load may be used by an RVS 

authority in setting priorities for hazard mitigation 

plans. The community may wish to upgrade 

buildings with more occupants first. As can be 

seen from the form (Figure 3-5), the occupancy 

load is defined in ranges such as 1-10, 11-100, 

101-1000, and 1000+ occupants. The range that 

best describes the average occupancy of the 

building is circled. For example, if an office 

building appears to have a daytime occupancy of 

200 persons, and an occupancy of only one or two 

persons otherwise, the maximum occupancy load 

is 101-1000 persons. If the occupancy load is 

estimated from building size and use, an inserted 

asterisk will automatically indicate that these are 

approximate data. 

3.6 Identifying Potential 

Nonstructural Falling Hazards 

Nonstructural falling hazards such as chimneys, 

parapets, cornices, veneers, overhangs and heavy 

cladding can pose life-safety hazards if not 

adequately anchored to the building. Although 

these hazards may be present, the basic lateralload system for the building may be adequate and 

require no further review. A series of four boxes 

have been included to indicate the presence of 

nonstructural falling hazards (see Figure 3-6). The 

falling hazards of major concern are: 

• Unreinforced Chimneys. Unreinforced 

masonry chimneys are common in older 

masonry and wood-frame dwellings. They are 

often inadequately tied to the house and fall 

when strongly shaken. If in doubt as to 

whether a chimney is reinforced or 

unreinforced, assume it is unreinforced. 

• Parapets. Unbraced parapets are difficult to 

identify from the street as it is sometimes 

difficult to tell if a facade projects above the 

roofline. Parapets often exist on three sides of 

the building, and their height may be visible 

from the back of the structure. 

• Heavy Cladding. Large heavy cladding 

elements, usually precast concrete or cut 

Figure 3-6 Portion of Data Collection Form for 

documenting nonstructural falling 

hazards. 
24 3: Completing the Data Collection Form FEMA 154 

stone, may fall off the building during an 

earthquake if improperly anchored. The loss 

of panels may also create major changes to the 

building stiffness (the elements are considered 

nonstructural but often contribute substantial 

stiffness to a building), thus setting up plan 

irregularities or torsion when only some fall. 

(Glass curtain walls are not considered as 

heavy cladding in the RVS procedure.) The 

existence of heavy cladding is of concern if 

the connections were designed and installed 

before the jurisdiction adopted seismic 

anchorage requirements (normally twice that 

for gravity loads). The date of such code 

adoption will vary with jurisdiction and should 

be established by an experienced design 

professional in the planning stages of the RVS 

process (see Section 2.4.2). 

If any of the above nonstructural falling 

hazards exist, the appropriate box should be 

checked. If there are any other falling hazards, the 

“Other” box should be checked, and the type of 

hazard indicated on the line beneath this box. Use 

the comments section if additional space is 

required. 

The RVS authority may later use this 

information as a basis for notifying the owner of 

potential problems. 

3.7 Identifying the Lateral-LoadResisting System and 

Documenting the Related Basic 

Structural Score 

The RVS procedure is based on the premise that 

the screener will be able to determine the 

building’s lateral-load-resisting system from the 

street, or to eliminate all those that it cannot 

possibly be. It is further assumed that the lateralload-resisting system is one of fifteen types that 

have been observed to be prevalent, based on 

studies of building stock in the United States. The 

fifteen types are consistent with the model 

building types identified in the FEMA 310 Report 

and the predecessor documents that have 

addressed seismic evaluation of buildings (e.g., 

ATC, 1987; BSSC, 1992)). The fifteen model 

building types used in this document, however, are 

an abbreviated subset of the 22 types now 

considered standard by FEMA; excluded from the 

FEMA 154 list are sub-classifications of certain 

framing types that specify that the roof and floor 

diaphragms are either rigid or flexible. 

3.7.1 Fifteen Building Types Considered 

by the RVS Procedure and Related 

Basic Structural Scores 

Following are the fifteen building types used in the 

RVS procedure. Alpha-numeric reference codes 

used on the Data Collection Form are shown in 

parentheses. 

1. Light wood-frame residential and commercial 

buildings smaller than or equal to 5,000 square 

feet (W1) 

2. Light wood-frame buildings larger than 5,000 

square feet (W2) 

3. Steel moment-resisting frame buildings (S1) 

4. Braced steel frame buildings (S2) 

5. Light metal buildings (S3) 

6. Steel frame buildings with cast-in-place 

concrete shear walls (S4) 

7. Steel frame buildings with unreinforced 

masonry infill walls (S5) 

8. Concrete moment-resisting frame buildings 

(C1) 

9. Concrete shear-wall buildings (C2) 

10. Concrete frame buildings with unreinforced 

masonry infill walls (C3) 

11. Tilt-up buildings (PC1) 

12. Precast concrete frame buildings (PC2) 

13. Reinforced masonry buildings with flexible 

floor and roof diaphragms (RM1) 

14. Reinforced masonry buildings with rigid floor 

and roof diaphragms (RM2) 

15. Unreinforced masonry bearing-wall buildings 

(URM) 

For each of these fifteen model building types, 

a Basic Structural Hazard Score has been 

computed that reflects the estimated likelihood 

that building collapse will occur if the building is 

subjected to the maximum considered earthquake 

ground motions for the region. The Basic 

Structural Hazard Scores are based on the damage 

and loss estimation functions provided in the 

FEMA-funded HAZUS damage and loss 

estimation methodology (NIBS, 1999). For more 

information about the development of the Basic 

Structural Hazard Scores, see the companion 

FEMA 155 report (ATC, 2002). 

The Basic Structural Scores are provided on 

each Data Collection Form in the first row of the 
FEMA 154 3: Completing the Data Collection Form 25 

structural scoring matrix in the lower portion of 

the Data Collection Form (see Figure 3-7). In high 

and moderate seismicity regions, these scores 

apply to buildings built after the initial adoption 

and enforcement of seismic codes, but before the 

relatively recent significant improvement of codes 

(that is, before the applicable benchmark year, as 

defined in Table 2-2). In low seismicity regions, 

they apply to all buildings except those designed 

and constructed after the applicable benchmark 

year, as defined in Table 2-2. 

A key issue to be addressed in the planning 

stage (as recommended in Section 2.4.2) is the 

identification of those years in which seismic 

codes were initially adopted and later significantly 

improved. If the RVS authority in high and 

moderate seismicity regions is unsure of the 

year(s) in which codes were initially adopted, the 

default year for all but PC1 (tiltup) buildings is 

1941, (the default year specified in the HAZUS 

criteria, NIBS, 1999). For PC1 (tiltup) buildings, 

the initial year in which effective seismic codes 

were specified is 1973 (ICBO, 1973). As 

described in Sections 3.8.5 and 3.8.6, the Data 

Collection Form includes Score Modifiers that 

provide a means for modifying the Basic 

Structural Hazard Score as a function of design 

and construction date. 

Brief summaries of the physical characteristics 

and expected earthquake performance of each of 

the fifteen model building types, along with a 

photograph of a sample exterior view, and the 

Basic Structural Scores for regions of low (L), 

moderate (M), and high (H) seismicity are 

provided in Table 3-1. 

Additional background information on the 

physical characteristics and earthquake 

performance of these building types, not essential 

to the RVS procedure, is provided in Appendix E. 

3.7.2 Identifying the Lateral-ForceResisting System 

At the heart of the RVS procedure is the task of 

identifying the lateral-force-resisting system from 

the street. Once the lateral-force-resisting system 

is identified, the screener finds the appropriate 

alpha-numeric code on the Data Collection Form 

and circles the Basic Structural Hazard Score 

immediately beneath it (see Figure 3-7). 

Ideally, the lateral-force-resisting system for 

each building to be screened would be identified 

prior to field work through the review and 

interpretation of construction documents for each 

building (i.e., during the planning stage, as 

discussed in Section 2.7). 

If prior determination of the lateral-forceresisting system is not possible through the review 

of building plans, which is the most likely 

scenario, this determination must be made in the 

field. In this case, the screener reviews spacing 

and size of windows, and the apparent 

construction materials to determine the lateralforce resisting system. If the screener cannot 

identify with complete assuredness the lateralforce-resisting system from the street, the screener 

should enter the building interior to verify the 

building type selected (see Section 3.7.3 for 

additional information on this issue.) 

If the screener cannot determine the lateralforce-resisting system, and access to the interior is 

not possible, the screener should eliminate those 

lateral-force-resisting systems that are not possible 

and assume that any of the others are possible. In 

this case the Basic Structural Hazard Scores for all 

possible lateral-force-resisting systems would be 

circled on the Data Collection Form. More 

guidance and options pertaining to this issue are 

provided in Section 3.9. 

Figure 3-7. Portion of Data Collection 

Form containing Basic 

Structural Hazard Scores. 
26 3: Completing the Data Collection Form FEMA 154

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance

W1

Light wood 

frame residential and 

commercial 

buildings 

equal to or 

smaller than 

5,000 square 

feet

H = 2.8

M = 5.2

L = 7.4

● Wood stud walls are typically 

constructed of 2-inch by 4-

inch vertical wood members 

set about 16 inches apart (2-

inch by 6-inch for multiple 

stories).

● Most common exterior finish 

materials are wood siding, 

metal siding, or stucco.

● Buildings of this type performed very well in past earthquakes due to inherent 

qualities of the structural system and because they are 

lightweight and low rise. 

● Earthquake-induced cracks in 

the plaster and stucco (if any) 

may appear, but are classified 

as non-structural damage. 

● The most common type of 

structural damage in older 

buildings results from a lack of 

connection between the 

superstructure and the foundation, and inadequate chimney support.

W2

Light wood 

frame buildings greater 

than 5,000 

square feet

H = 3.8

M =4.8

L = 6.0

● These are large apartment 

buildings, commercial buildings or industrial structures 

usually of one to three stories, 

and, rarely, as tall as six stories.
FEMA 154 3: Completing the Data Collection Form 27

S1

Steel 

momentresisting 

frame

H = 2.8

M = 3.6

L = 4.6

● Typical steel moment-resisting frame structures usually 

have similar bay widths in 

both the transverse and longitudinal directions, around 

20-30 ft. 

● The floor diaphragms are usually concrete, sometimes over 

steel decking. This structural 

type is used for commercial, 

institutional and public buildings. 

● The 1994 Northridge and 

1995 Kobe earthquakes 

showed that the welds in steel 

moment- frame buildings 

were vulnerable to severe 

damage. The damage took the 

form of broken connections 

between the beams and columns.

S2

Braced steel 

frame

 Zoom-in of upper photo

H = 3.0

M = 3.6

L = 4.8

● These buildings are braced 

with diagonal members, 

which usually cannot be 

detected from the building 

exterior.

● Braced frames are sometimes 

used for long and narrow 

buildings because of their stiffness. 

● From the building exterior, it is 

difficult to tell the difference 

between steel moment 

frames, steel braced frames, 

and steel frames with interior 

concrete shear walls.

● In recent earthquakes, braced 

frames were found to have 

damage to brace connections, especially at the lower 

levels. 

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
28 3: Completing the Data Collection Form FEMA 154

S3

Light metal 

building

H = 3.2

M = 3.8

L = 4.6

● The structural system usually

consists of moment frames in 

the transverse direction and 

braced frames in the longitudinal direction, with corrugated sheet-metal siding. In 

some regions, light metal 

buildings may have partialheight masonry walls.

● The interiors of most of these 

buildings do not have interior 

finishes and their structural 

skeleton can be seen 

easily.

● Insufficient capacity of tension 

braces can lead to their elongation and consequent building damage during 

earthquakes.

● Inadequate connection to a 

slab foundation can allow the 

building columns to slide on 

the slab.

● Loss of the cladding can 

occur.

S4

Steel frames 

with cast-inplace concrete shear 

walls

H = 2.8

M = 3.6

L = 4.8

● Lateral loads are resisted by 

shear walls, which usually surround elevator cores and stairwells, and are covered by 

finish materials.

● An interior investigation will 

permit a wall thickness check. 

More than six inches in thickness usually indicates a concrete wall.

● Shear cracking and distress 

can occur around openings in 

concrete shear walls during 

earthquakes.

● Wall construction joints can 

be weak planes, resulting in 

wall shear failure below 

expected capacity.

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
FEMA 154 3: Completing the Data Collection Form 29

S5

Steel frames 

with unreinforced 

masonry infill 

walls

H = 2.0

M = 3.6

L = 5.0

● Steel columns are relatively 

thin and may be hidden in 

walls. 

● Usually masonry is exposed 

on exterior with narrow piers 

(less than 4 ft wide) between 

windows.

● Portions of solid walls will 

align vertically.

● Infill walls are usually two to 

three wythes thick. 

● Veneer masonry around columns or beams is usually 

poorly anchored and detaches 

easily.

C1

Concrete 

momentresisting 

frames

H = 2.5

M = 3.0

L = 4.4

● All exposed concrete frames 

are reinforced concrete (not 

steel frames encased in concrete).

● A fundamental factor governing the performance of concrete moment-resisting frames 

is the level of ductile detailing. 

● Large spacing of ties in columns can lead to a lack of 

concrete confinement and 

shear failure.

● Lack of continuous beam reinforcement can result in hinge 

formation during load reversal.

● The relatively low stiffness of 

the frame can lead to substantial nonstructural damage.

● Column damage due to 

pounding with adjacent buildings can occur.

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
30 3: Completing the Data Collection Form FEMA 154

C2

Concrete 

shear wall 

buildings

H = 2.8

M = 3.6

L = 4.8

● Concrete shear-wall buildings 

are usually cast in place, and 

show typical signs of cast-inplace concrete.

● Shear-wall thickness ranges 

from 6 to 10 inches.

● These buildings generally perform better than concrete 

frame buildings.

● They are heavier than steelframe buildings but more rigid 

due to the shear walls. 

● Damage commonly observed 

in taller buildings is caused by 

vertical discontinuities, 

pounding, and irregular configuration.

C3

Concrete 

frames with 

unreinforced 

masonry infill 

walls

H =1.6

M = 3.2

L = 4.4

● Concrete columns and beams 

may be full wall thickness and 

may be exposed for viewing 

on the sides and rear of the 

building. 

● Usually masonry is exposed 

on the exterior with narrow 

piers (less than 4 ft wide) 

between windows.

● Portions of solid walls will 

align vertically.

● This type of construction was 

generally built before 1940 in 

high-seismicity regions but 

continues to be built in other 

regions. 

● Infill walls tend to buckle and 

fall out-of-plane when subjected to strong lateral out-ofplane forces. 

● Veneer masonry around columns or beams is usually 

poorly anchored and detaches 

easily.

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
FEMA 154 3: Completing the Data Collection Form 31

PC1

Tilt-up buildings

Partial roof collapse due to failed diaphragm-to-wall connection

H = 2.6

M = 3.2

L = 4.4

● Tilt-ups are typically one or 

two stories high and are basically rectangular in plan. 

● Exterior walls were traditionally formed and cast on the 

ground adjacent to their final 

position, and then “tilted-up” 

and attached to the floor slab. 

● The roof can be a plywood 

diaphragm carried on wood 

purlins and glulam beams or a 

light steel deck and joist system, supported in the interior 

of the building on steel pipe 

columns. 

● Weak diaphragm-to-wall 

anchorage results in the wall 

panels falling and the collapse 

of the supported diaphragm 

(or roof). 

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
32 3: Completing the Data Collection Form FEMA 154

PC2

Precast concrete frame 

buildings

Building under construction

Detail of the precast components

Building nearing completion

H = 2.4

M = 3.2

L = 4.6

● Precast concrete frames are, 

in essence, post and beam 

construction in concrete. 

● Structures often employ concrete or reinforced masonry 

(brick or block) shear walls.

● The performance varies 

widely and is sometimes poor. 

● They experience the same 

types of damage as shear wall 

buildings (C2).

● Poorly designed connections 

between prefabricated elements can fail.

● Loss of vertical support can 

occur due to inadequate bearing area and insufficient connection between floor 

elements and columns.

● Corrosion of metal connectors 

between prefabricated elements can occur.

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
FEMA 154 3: Completing the Data Collection Form 33

RM1

Reinforced 

masonry 

buildings with 

flexible diaphragms

Truss-joists support plywood and lightweight concrete slab

Detail showing reinforced masonry

H = 2.8

M = 3.6

L = 4.8

● Walls are either brick or concrete block.

● Wall thickness is usually 8 

inches to 12 inches.

● Interior inspection is required 

to determine if diaphragms 

are flexible or rigid.

● The most common floor and 

roof systems are wood, light 

steel, or precast concrete.

● These buildings can perform 

well in moderate earthquakes 

if they are adequately reinforced and grouted, with sufficient diaphragm anchorage.

● Poor construction practice can 

result in ungrouted and unreinforced walls, which will fail 

easily. 

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
34 3: Completing the Data Collection Form FEMA 154

RM2

Reinforced 

masonry 

buildings with 

rigid diaphrams

H = 2.8

M = 3.4

L = 4.6

● Walls are either brick or concrete block.

● Wall thickness is usually 8 

inches to 12 inches.

● Interior inspection is required 

to determine if diaphragms 

are flexible or rigid.

● The most common floor and 

roof systems are wood, light 

steel, or precast concrete.

● These buildings can perform 

well in moderate earthquakes 

if they are adequately reinforced and grouted, with sufficient diaphragm anchorage.

● Poor construction practice can 

result in ungrouted and unreinforced walls, which will fail 

easily. 

URM

Unreinforced 

masonry 

buildings

H = 1.8

M = 3.4

L = 4.6

● These buildings often used 

weak lime mortar to bond the 

masonry units together. 

● Arches are often an architectural characteristic of older 

brick bearing wall buildings.

● Other methods of spanning 

are also used, including steel 

and stone lintels. 

● Unreinforced masonry usually shows header bricks in the 

wall surface.

● The performance of this type 

of construction is poor due to 

lack of anchorage of walls to 

floors and roof, soft mortar, 

and narrow piers between 

window openings.

Table 3-1 Build Type Descriptions, Basic Structural Hazard Scores, and Performance in Past Earthquakes

 (Continued)

Building 

Identifier Photograph

Basic Structural 

Hazard Score Characteristics and Performance
FEMA 154 3: Completing the Data Collection Form 35 

Determining the lateral-force-resisting 

system in the field is often difficult. A useful 

first step is to determine if the building structure 

is a frame or a bearing wall. Examples of frame 

structures and bearing wall structures are shown 

in Figure 3-8, 3-9, and 3-10. 

Information to assist the screener in 

distinguishing if the building is a bearing wall 

or frame structure is provided in the side bar. 

Once this determination has been made and the 

Distinguishing Between Frame and Bearing Wall Building 

Systems. 

A frame structure (for example, S1, S2, S3, S4, C1, PC2) is made 

up of beams and columns throughout the entire structure, resisting

both vertical and lateral loads. A bearing wall structure (for 

example, PC1 and URM) uses vertical-load-bearing walls, which 

are more or less solid, to resist the vertical and lateral loads. 

When a building has large openings on all sides, it is 

probably a frame structure as opposed to a bearing wall structure. 

A common characteristic of a frame structure is the rectangular 

grid patterns of the facade, indicating the location of the columns 

and girders behind the finish material. This is particularly 

revealing when windows occupy the entire opening in the frame, 

and no infill wall is used. A newer multistory commercial 

building should be assumed to be a frame structure, even though 

there may exist interior shear walls carrying the lateral loads (this 

would be a frame structure with shear walls). 

Bearing wall systems carry vertical and lateral loads with 

walls rather than solely with columns. Structural floor members 

such as slabs, joists, and beams, are supported by load-bearing 

walls. A bearing wall system is thus characterized by more or less 

solid walls and, as a rule of thumb, a load-bearing wall will have 

more solid areas than openings. It also will have no wide 

openings, unless a structural lintel is used. 

Some bearing-wall structures incorporate structural columns, 

or are partly frame structures. This is especially popular in 

multistory commercial buildings in urban lots where girders and 

columns are used in the ground floor of a bearing wall structure to 

provide larger openings for retail spaces. Another example is 

where the loads are carried by both interior columns and a 

perimeter wall. Both of these examples should be considered as 

bearing wall structures, because lateral loads are resisted by the 

bearing walls. Bearing wall structures sometimes utilize only two 

walls for load bearing. The other walls are non-load-bearing and 

thus may have large openings. Therefore, the openness of the 

front elevation should not be used to determine the structure type. 

The screener should also look at the side and rear facades. If at 

least two of the four exterior walls appear to be solid then it is 

likely that it is a bearing wall structure.

Window openings in older frame structures can sometimes be 

misleading. Since wide windows were excessively costly and 

fragile until relatively recently, several narrow windows separated 

by thin mullions are often seen in older buildings. These thin 

mullions are usually not load bearing. When the narrow windows 

are close together, they constitute a large opening typical of a 

frame structure, or a window in a bearing wall structure with steel 

lintels. 

Whereas open facades on all sides clearly indicate a frame 

structure, solid walls may be indicative of a bearing wall structure 

or a frame structure with solid infill walls. Bearing walls are 

usually much thicker than infill walls, and increase in thickness in 

the lower stories of multi-story buildings. This increase in wall 

thickness can be detected by comparing the wall thickness at 

windows on different floors. Thus, solid walls can be identified 

as bearing or non-bearing walls according to their thickness, if the 

structural material is known. 

A bearing wall system is sometimes called a box system. 

Figure 3-9 Typical bearing wall structure. 

Features include small window 

span, at least two mostly solid walls, 

and thick load-bearing walls. 

Figure 3-8 Typical frame structure. Features

include: large window spans, 

window openings on many 

sides, and clearly visible columnbeam grid pattern. 
36 3: Completing the Data Collection Form FEMA 154 

principal structural material is identified, the 

essential information for determining the lateralforce-resisting system has been established. It is 

then useful to know that: 

• unreinforced masonry and tilt-up buildings are 

usually bearing-wall type, 

• steel buildings and pre-cast concrete buildings 

are usually frame type, and 

• concrete and reinforced masonry buildings 

may be either type. 

A careful review of Table 3-1 and the 

information provided in Appendices D and E, 

along with training by knowledgeable building 

design professionals, should assist the screener in 

the determination of lateral-force-resisting 

systems. There will be some buildings for which 

the lateral-force-resisting system cannot be 

identified because of their facade treatment. In 

this case, the screener should eliminate those 

lateral-force-resisting systems that are not possible 

and assume that any of the others are possible. 

3.7.3 Interior Inspections 

Ideally, whenever possible, the screener should 

seek access to the interior of the building to 

identify, or verify, the lateral-force-resisting 

system for the building. In the case of reinforced 

masonry buildings, entry is particularly important 

so that the screener can distinguish between RM1 

buildings, which have flexible floor and roof 

diaphragms, and RM2 buildings, which have rigid 

floor and roof diaphragms. 

As with the exterior inspection, the interior 

process should be performed in a logical manner, 

either from the basement to the roof, or roof to 

basement. The screener should look at each floor 

thoroughly. 

The RVS procedure does not require the 

removal of finish materials that are otherwise 

permanently affixed to the structure. There are a 

number of places within a building where it is 

possible to see the exposed structure. The 

following are some ways to determine the 

structure type. 

1. If the building has a basement that is not 

occupied, the first-floor framing may be 

exposed. The framing will usually be 

representative of the floor framing throughout 

the building. 

2. If the structural system is a steel or concrete 

frame, the columns and beams will often be 

exposed in the basement. The basement walls 

will likely be concrete, but this does not mean 

that they are concrete all the way to the roof. 

3. High and mid-rise structures usually have one 

or more levels of parking below the building. 

When fireproofed steel columns and girders 

are seen, the screener can be fairly certain that 

the structure is a steel building (S1, S2, or S4 

see Figure 3-11). 

4. If the columns and beams are constructed of 

concrete, the structure type is most likely a 

concrete moment-frame building (C1, see 

Figure 3-12). However, this is not guaranteed 

as some buildings will use steel framing above 

the ground floor. To ascertain the building 

type, the screener will need to look at the 

columns above the first floor. 

5. If there is no basement, the mechanical 

equipment rooms may show what the framing 

is for the floor above. 

Example of a Frame Building

Example of a Bearing Wall Structure 

Figure 3-10 Frame and bearing wall structures 
FEMA 154 3: Completing the Data Collection Form 37 

6. If suspended ceilings are used, one of the 

ceiling tiles can be lifted and simply pushed 

back. In many cases, the floor framing will 

then be exposed. Caution should be used in 

identifying the framing materials, because 

prior to about 1960, steel beams were encased 

in concrete to provide fireproofing. If steel 

framing is seen with what appears to be 

concrete beams, most likely these are steel 

beams encased in concrete. 

7. If plastered ceilings are observed above 

suspended ceilings, the screener will not be 

able to identify the framing materials; 

however, post-1960 buildings can be 

eliminated as a possibility because these 

buildings do not use plaster for ceilings. 

8. At the exterior walls, if the structural system is 

a frame system, there will be regularly spaced 

furred out places. These are the building 

columns. If the exterior walls between the 

columns are constructed of brick masonry and 

the thickness of the wall is 9 inches or more, 

the structure type is either steel frame with 

unreinforced masonry infill (S5) or concrete 

frame with unreinforced masonry infill (C3). 

9. Pre-1930 brick masonry buildings that are six 

stories or less in height and that have woodfloor framing supported on masonry ledges in 

pockets formed in the wall are unreinforced 

masonry bearing-wall buildings (URM). 

3.7.4 Screening Buildings with More Than 

One Lateral-Force-Resisting System 

In some cases, the screener may observe buildings 

having more than one lateral-force-resisting 

system. Examples might include a wood-frame 

building atop a precast concrete parking garage, or 

a building with reinforced concrete shear walls in 

one direction and a reinforced moment-resisting 

frame in the other. 

Buildings that incorporate more than one 

lateral-force-resisting system should be evaluated 

for all observed types of structural systems, and 

the lowest Final Structural Score, S, should 

govern. 

Figure 3-11 Interior view showing fireproofed columns and beams, 

which indicate a steel 

building (S1, S2, or S4). 

 Figure 3-12 Interior view showing concrete columns and girders, which indicate a concrete moment frame (C1). 
38 3: Completing the Data Collection Form FEMA 154 

3.8 Identifying Seismic Performance 

Attributes and Recording Score 

Modifiers 

This section discusses major factors that 

significantly impact structural performance during 

earthquakes, and the assignment of Score 

Modifiers related to each of these factors 

(attributes). The severity of the impact on 

structural performance varies with the type of 

lateral-force-resisting system; thus the assigned 

Score Modifiers depend on building type. Score 

Modifiers associated with each performance 

attribute are indicated in the scoring matrix on the 

Data Collection Form (see Figure 3-13). Score 

Modifiers for the building being screened are 

circled in the appropriate column (i.e., under the 

reference code for the identified lateral-forceresisting system for that building). 

Following are descriptions of each 

performance attribute, along with guidance on 

how to recognize each from the street. If a 

performance attribute does not apply to a given 

building type, the Score Modifier is indicated with 

“N/A”, which indicates “not applicable.” 

3.8.1 Mid-Rise Buildings 

If the building has 4 to 7 stories, it is considered a 

mid-rise building, and the score modifier 

associated with this attribute should be circled. 

3.8.2 High-Rise Buildings 

If the building has 8 or more stories, it is 

considered a high-rise building, and the score 

modifier associated with this attribute should be 

circled. 

3.8.3 Vertical Irregularity 

This performance attribute applies to all building 

types. Examples of vertical irregularity include 

buildings with setbacks, hillside buildings, and 

buildings with soft stories (see illustrations of 

example vertical irregularities in Figure 3-14). 

If the building is irregularly shaped in 

elevation, or if some walls are not vertical, then 

apply the modifier (see example in Figure 3-15). 

If the building is on a steep hill so that over 

the up-slope dimension of the building the hill 

rises at least one story height, a problem may exist 

because the horizontal stiffness along the lower 

side may be different from the uphill side. In 

addition, in the up-slope direction, the stiff short 

columns attract the seismic shear forces and may 

fail. In this case the performance modifier is 

applicable. See Figure 3-14 for an example. 

Score Modifier

Figure 3-13. Portion of Data Collection Form 

containing attributes that modify 

performance and associated score 

modifiers. 
FEMA 154 3: Completing the Data Collection Form 39 

Figure 3-15 Example of setbacks (see Figure 3-14) and a soft first story. 

Setback

Soft Story

A soft story exists if the stiffness of one story 

is dramatically less than that of most of the others 

(see Figure 3-15). Examples are shear walls or 

infill walls not continuous to the foundation. Soft 

stories are difficult to verify without knowledge of 

how the building was designed and how the lateral 

forces are to be transferred from story to story. In 

other words, there may be shear walls in the 

building that are not visible from the street. 

However, if there is doubt, it is best to be 

conservative and indicate the existence of a soft 

story by circling the vertical irregularity Score 

Modifier. Use an asterisk and the comment 

section to explain the source of uncertainty. In 

many commercial buildings, the first story is soft 

due to large window openings for display 

purposes. If one story is particularly tall or has 

windows on all sides, and if the stories above have 

fewer windows, then it is probably a soft story. 

A building may be adequate in one direction 

but be “soft” in the perpendicular direction. For 

example, the front and back walls may be open but 

the side walls may be solid. Another common 

example of soft story is “tuck under” parking 

commonly found in apartment buildings (see 

Figure 3-16). Several past earthquakes in 

California have shown the vulnerability of this 

type of construction. 

Vertical irregularity is a difficult characteristic 

to define, and considerable judgment and 

experience are required for identification purposes. 

Setbacks Hillside Soft Story

Figure 3-14 Elevation views showing vertical irregularities, with arrows indicating locations of particular concern.
40 3: Completing the Data Collection Form FEMA 154 

3.8.4 Plan Irregularity 

If a building has a vertical or plan irregularity, as 

described below, this modifier applies. Plan 

irregularity can affect all building types. 

Examples of plan irregularity include buildings 

with re-entrant corners, where damage is likely to 

occur; buildings with good lateral-load resistance 

in one direction but not in the other; and buildings 

with major stiffness eccentricities in the lateralforce-resisting system, which may cause twisting 

(torsion) around a vertical axis. 

Buildings with re-entrant corners include those 

with long wings that are E, L, T, U, or + shaped 

(see Figures 3-17 and 3-18). See SEAOC (1996) 

for further discussion of this issue.) 

Plan irregularities causing torsion are 

especially prevalent among corner buildings, in 

which the two adjacent street sides of the building 

are largely windowed and open, whereas the other 

two sides are generally solid. Wedge-shaped 

buildings, triangular in plan, on corners of streets 

not meeting at 90°, are similarly susceptible (see 

Figure 3-19). 

Although plan irregularity can occur in all 

building types, primary concern lies with wood, 

tilt-up, pre-cast frame, reinforced masonry and 

unreinforced masonry construction. Damage at 

connections may significantly reduce the capacity 

of a vertical-load-carrying element, leading to 

partial or total collapse. 

3.8.5 Pre-Code 

This Score Modifier applies for buildings in high 

and moderate seismicity regions and is applicable 

if the building being screened was designed and 

constructed prior to the initial adoption and 

enforcement of seismic codes applicable for that 

building type (e.g., steel moment frame, S1). The 

year(s) in which seismic codes were initially 

adopted and enforced for the various model 

building types should have been identified as part 

Figure 3-16 Example of soft story conditions, 

where parking requirements result

in large weak openings. 

Figure 3-17 Plan views of various building configurations showing plan irregularities; arrows indicate possible 

areas of damage. 

L-Shaped T-Shaped U-Shaped 

Large Opening 

Weak Link Between Larger 

Building Plan Areas 
FEMA 154 3: Completing the Data Collection Form 41 

of the Data Collection Form review process during 

the pre-planning stage (as recommended in 

Section 2.4.2). If this determination was not made 

during the planning stage, the default year is 1941, 

for all building types except PC1, in which case it 

is 1973. Because of the method used to calculate 

the Basic Structural Hazard Scores, this modifier 

does not apply to buildings in the low seismicity 

region. 

3.8.6 Post-Benchmark 

This Score Modifier is applicable if the building 

being screened was designed and constructed after 

significantly improved seismic codes applicable 

for that building type (e.g., concrete moment 

frame, C1) were adopted and enforced by the local 

jurisdiction. The year in which such 

improvements were adopted is termed the 

“benchmark” year. Benchmark year(s) for the 

various model building types should have been 

identified as part of the Data Collection Form 

review process during the pre-planning stage (as 

recommended in Section 2.4.2). Benchmark years 

for the various building types (designed in 

accordance with various model codes) are 

provided in Table 2-2. 

3.8.7 Soil Type C, D, or E 

Score Modifiers are provided for Soil Type C, 

Type D, and Type E. The appropriate modifier 

should be circled if one of these soil types exists at 

the site (see Section 3.4 for additional discussion 

regarding the determination of soil type). If 

sufficient guidance or data are not available during 

the planning stage to classify the soil type as A 

through E, a soil type E should be assumed. 

However, for one- or two-story buildings with a 

roof height equal to or less than 25 feet, a class D 

soil type may be assumed if the actual site 

conditions are not known. 

There is no Score Modifier for Type F soil 

because buildings on soil type F cannot be 

screened effectively by the RVS procedure. A 

geotechnical engineer is required to confirm the 

soil type F and an experienced professional 

engineer is required for building evaluation. 

3.9 Determining the Final Score 

The Final Structural Score, S, is determined for a 

given building by adding (or subtracting) the 

Score Modifiers for that building to the Basic 

Structural Hazard Score for the building. The 

result is documented in the section of the form 

entitled Final Score (see Figure 3-20). Based on 

this information, and the “cut-off” score selected 

during the pre-planning process (see Section 

2.4.3), the screener then decides if a detailed 

evaluation is required for the building and circles 

“YES” or “NO” in the lower right-hand box (see 

Figure 3-20). Additional guidance on this issue is 

provided in Sections 4.1, and 4.2. 

When the screener is uncertain of the building 

type, an attempt should be made to eliminate all 

unlikely building types. If the screener is still left 

with several choices, computation of the Final 

Structural Score S may be treated several ways: 

1. The screener may calculate S for all the 

remaining options and choose the lowest 

Figure 3-19 Example of a building, triangular in 

plan, subject to torsion. 

Figure 3-18 Example of a building, with a plan 

irregularity, with two wings meeting at 

right angles. 
42 3: Completing the Data Collection Form FEMA 154 

Figure 3-20 Location on Data Collection Form 

where the final score, comments, and 

an indication if the building needs 

detailed evaluation are documented. 

score. This is a conservative approach, and 

has the disadvantage that it may be too 

conservative and the assigned score may 

indicate that the building presents a greater 

risk than it actually does. This conservative 

approach will not pose problems in cases 

where all the possible remaining building 

types result in scores below the cut-off value. 

In all these cases the building has 

characteristics that justify further review 

anyway by a design professional experienced 

in seismic design. 

2. If the screener has little or no confidence 

about any choice for the structural system, the 

screener should write DNK below the word 

“Building Type” (see Figure 3-7), which 

indicates the screener does not know. In this 

case there should be an automatic default to 

the need for a detailed review of the building 

by an experienced design professional. A more 

detailed field inspection would include 

entering the building, and examining the 

basement, roof, and all structural elements. 

Which of these two options the RVS authority 

wishes to adopt should be decided in the RVS 

planning phase (see Section 2.3). 

3.10 Photographing the Building 

At least one photograph of the building should be 

taken for identification purposes. The screener is 

not limited to one photograph. A photograph 

contains much more information, although perhaps 

less emphasized, than the elevation sketch. Large 

buildings are difficult to photograph from the 

street and the camera lens introduces distortion for 

high-rise buildings. If possible, the photograph 

should be taken from a sufficient distance to 

include the whole building, and such that adjacent 

faces are included. A wide angle or a zoom lens 

may be helpful. Strong sunlit facades should be 

avoided, as harsh contrasts between shadows and 

sunlit portions of the facade will be introduced. 

Lastly, if possible, the front of the building should 

not be obscured by trees, vehicles or other objects, 

as they obscure the lower (and often the most 

important) stories. 

3.11 Comments Section 

This last section of the form (see Figure 3-20) is 

for recording any comments the screener may 

wish to make regarding the building, occupancy, 

condition, quality of the data or unusual 

circumstances of any type. For example, if not all 

significant details can be effectively photographed 

or drawn, the screener could describe additional 

important information in the comments area. 

Comments may be made on the strength of mortar 

used in a masonry wall, or building features that 

can be seen at or through window openings. Other 

examples where comments are helpful are 

described throughout Chapter 3.
FEMA-154 4: Using the RVS Procedure Results 43 

Chapter 4 

Using the RVS Procedure Results 

The rapid visual screening procedure presented in 

this Handbook is meant to be the preliminary 

screening phase of a multi-phase procedure for 

identifying earthquake-hazardous buildings. 

Buildings identified by this procedure as 

potentially hazardous must be analyzed in more 

detail by an experienced seismic design 

professional. Because rapid visual screening is 

designed to be performed from the street, with 

interior inspection not always possible, hazardous 

details will not always be visible, and seismically 

hazardous buildings may not be identified as such. 

Conversely, buildings identified as potentially 

hazardous may prove to be adequate. 

Since the original publication of FEMA 154 in 

1988, the RVS procedure has been widely used by 

local communities and government agencies. A 

critical issue in the implementation of FEMA 154 

has been the interpretation of the Final Structural 

Score, S, and the selection of a “cut-off” score, 

below which a detailed seismic evaluation of the 

building by a design professional in seismic design 

is required. 

Following are discussions on: (1) interpretation and selection of the “cut-off” score; (2) prior 

uses of the FEMA 154 RVS procedure, including 

decisions regarding the “cut-off” score; and (3) 

other possible uses of the FEMA 154 RVS 

procedure, including resources needed for the 

various possible uses. These discussions are 

intended to illuminate both the limitations and 

potential applications of the RVS procedure. 

4.1 Interpretation of RVS Score 

Having employed the RVS procedure and 

determined the building’s Final Structural Score, 

S, which is based on the Basic Structural Hazard 

Score and Score Modifiers associated with the 

various performance attributes, the RVS authority 

is naturally faced with the question of what these S

scores mean. Fundamentally, the final S score is 

an estimate of the probability (or chance) that the 

building will collapse if ground motions occur that 

equal or exceed the maximum considered 

earthquake (MCE) ground motions (the current 

FEMA 310 ground motion specification for 

detailed seismic evaluation of buildings). These 

estimates of the score are based on limited 

observed and analytical data, and the probability 

of collapse is therefore approximate. For example, 

a final score of S = 3 implies there is a chance of 1 

in 103

, or 1 in 1000, that the building will collapse 

if such ground motions occur. A final score of S = 

2 implies there is a chance of 1 in 102

, or 1 in 100, 

that the building will collapse if such ground 

motions occur. (Additional information about the 

basis for the RVS scoring system is provided in 

the second edition of the companion FEMA 155 

Report, Rapid Visual Screening of Buildings for 

Potential Seismic Hazards: Supporting 

Documentation.) An understanding and 

appreciation of the physical essence of the scoring 

system, as described above, will facilitate the 

interpretation of results from implementation of 

the RVS procedure. 

4.2 Selection of RVS “Cut-Off” Score 

One of the most difficult issues pertaining to rapid 

visual screening is answering the question, “What 

is an acceptable S?” This is a question for the 

community that involves the costs of safety versus 

the benefits. The costs of safety include: 

• the costs of reviewing and investigating in 

detail hundreds or thousands of buildings in 

order to identify some fraction of those that 

would actually sustain major damage in an 

earthquake; and 

• the costs associated with rehabilitating those 

buildings finally determined to be 

unacceptably weak. 

The most compelling benefit is the saving of lives 

and prevention of injuries due to reduced damage 

in those buildings that are rehabilitated. This 

reduced damage includes not only less material 

damage, but fewer major disruptions to daily lives 

and businesses. The identification of hazardous 

buildings and the mitigation of their hazards are 

critical because there are thousands of existing 

buildings in all parts of the United States that may 

suffer severe damage or possible collapse in the 

event of strong ground shaking. Such damage or 
44 4: Using the RVS Procedure Results FEMA-154 

collapse can be accompanied by loss of life and 

serious injury. In a great earthquake deaths could 

number in the thousands. 

Each community needs to engage in some 

consideration of these costs and benefits of 

seismic safety, and decide what value of S is an 

appropriate “cut-off’ for their situation. The final 

decision involves many non-technical factors, and 

is not straightforward. Perhaps the best 

quantification of the risk inherent in modern 

building codes was a study regarding design 

practice by the National Bureau of Standards 

(NBS, 1980), which observed: 

In selecting the target reliability it was 

decided, after carefully examining the 

resulting reliability indices for the many 

design situations, that a β0 =3 is a 

representative average value for many 

frequently used structural elements when they 

are subjected to gravity loading, while β0 

=2.5 and β0 = 1.75 are representative values 

for loads that include wind and earthquake, 

respectively3

. 

In other words, present design practice is such 

that a value of S of about 3 is appropriate for dayto-day loadings, and a value of about 2, or 

somewhat less, is appropriate for infrequent, but 

possible, earthquake loadings. 

More recently, recommendations for seismic 

design criteria for new steel moment-frame 

buildings (SAC, 2000) concluded that: 

...it is believed that...structures designed in 

accordance with [these recommendations] 

provide in excess of 90% confidence of being 

able to withstand [shaking that has a 2% 

probability of exceedance in 50 years] without 

global collapse....

This statement can be shown to be equivalent to 

the findings in the NBS (1980) study. 

Unless a community itself considers the cost 

and benefit aspects of seismic safety, an S value of 

about 2.0 is a reasonable preliminary value to use 

within the context of RVS to differentiate 

adequate buildings from those potentially 

inadequate and thus requiring detailed review. Use 

of a higher cut-off S value implies greater desired 

safety but increased community-wide costs for 

evaluations and rehabilitation; use of a lower value 

of S equates to increased seismic risk and lower 

 

3 β0 as used in the National Bureau of Standards study 

is approximately equivalent to S as used herein. 

short-term community-wide costs for evaluations 

and rehabilitation (prior to an earthquake). 

Further guidance on cost and other societal 

implications of seismic rehabilitation of hazardous 

buildings is available in other publications of the 

FEMA report series on existing buildings (see 

FEMA-156 and FEMA-157, Typical Costs for 

Seismic Rehabilitation of Buildings, 2nd Edition, 

Volumes 1 and 2, and FEMA-255 and FEMA-256,

Seismic Rehabilitation of Federal Buildings – A 

Benefit/Cost Model, Volumes 1 and 2 (VSP, 

1994). 

4.3 Prior Uses of the RVS Procedure 

During the decade following publication of the 

first edition of the FEMA 154 Handbook, the rapid 

visual screening procedure was used by privatesector organizations and government agencies to 

evaluate more than 70,000 buildings nationwide 

(ATC, 2002). As reported at the FEMA 154 Users 

Workshop in San Francisco in September 2000 

(see second edition of FEMA 155 report for 

additional information), these applications 

included surveys of (1) commercial buildings in 

Beverly Hills, California, (2) National Park 

Service facilities, (3) pubic buildings and 

designated shelters in southern Illinois; (4) U. S. 

Army facilities, (5) facilities of the U. S. 

Department of the Interior and (6) buildings in 

other local communities and for other government 

agencies. The results from some of these efforts 

are described below. 

In its screening of 11,500 buildings using the 

FEMA 154 RVS procedure, the U. S. Army Corps 

of Engineers Civil Engineering Research 

Laboratory (CERL) used a cut-off score of 2.5, 

rather than 2.0 (S. Sweeney, oral communication, 

September 2000), with the specific intent of using 

a more conservative approach. As a result of the 

FEMA 154 screening, approximately 5,000 

buildings had final S scores less than 2.5. These 

buildings, along with a subset of buildings that had 

FEMA 154 scores higher than 2.5, but were of 

concern for other reasons, were further evaluated 

in detail using the FEMA 178 NEHRP Handbook 

for the Seismic Evaluation of Existing Buildings

[BSSC, 1992]). Results from the subsequent 

FEMA 178 evaluations indicated that some 

buildings that failed the FEMA 154 RVS 

procedure (that is, had scores less than 2.5) did not 

fail the FEMA 178 evaluations and that some that 

passed the FEMA 154 RVS procedure (with 

scores higher than 2.5) did not pass the FEMA 178 

evaluation (that is, were found to have inadequate 

seismic resistance). This finding emphasizes the 
FEMA 154 4: Using the RVS Procedure Results 45 

concern identified at the beginning of this chapter 

that the use of FEMA 154 may not identify 

potentially earthquake hazardous buildings as 

such, and that buildings identified as potentially 

hazardous may prove to be adequate. 

Other conclusions and recommendations 

pertaining to the use of the FEMA 154 RVS 

procedure that emanated from these applications 

included the following: 

• Involve design professionals in RVS 

implementation whenever possible to ensure 

that the lateral-force-resisting structural 

systems are correctly identified (such 

identification is particularly difficult in 

buildings that have been remodeled and added 

to over the years); 

• Conduct intensive training for screeners so 

that they fully understand how to implement 

the methodology, in all of its aspects; 

• Inspect both the exterior and, if at all possible, 

the interior of the building; 

• Review construction drawings as part of the 

screening process; 

• Review soils information prior to 

implementation of the methodology in the 

field; and 

• Interpret the results from FEMA 154 

screenings in a manner consistent with the 

level of resources available for the screening 

(for example, cut-off scores may be dictated 

by budget constraints). 

Most of these recommendations were incorporated 

in the updated RVS procedure described in this 

Handbook. 

4.4 Other Possible Uses of the RVS 

Procedure 

In addition to identifying potentially 

seismically hazardous buildings needing further 

evaluation, results from RVS surveys can also be 

used for other purposes, including: (1) designing 

seismic hazard mitigation programs for a 

community (or agency); (2) ranking a 

community’s (or agency’s) seismic rehabilitation 

needs; (3) developing inventories of buildings for 

use in regional earthquake damage and loss impact 

assessments; (4) developing inventories of 

buildings for use in planning postearthquake 

building safety evaluation efforts; and (5) 

developing building-specific seismic vulnerability 

information for purposes such as insurance rating, 

decision making during building ownership 

transfers, and possible triggering of remodeling 

requirements during the permitting process. 

Following are descriptions of how RVS results 

could be used for several of these purposes. 

4.4.1 Using RVS Scores as a Basis for 

Hazardous Building Mitigation 

Programs 

Communities need to develop hazard mitigation 

plans to establish a solid foundation for the 

detailed seismic evaluation and rehabilitation of 

buildings. In developing any hazardous buildings 

mitigation program, the cost effectiveness of the 

seismic evaluation and rehabilitation work must be 

determined. The costs should be evaluated against 

the direct benefits of the seismic rehabilitation 

program (that is, reduced physical damage, 

reduced injuries and loss of life). Additionally, 

secondary benefits to the community should be 

considered with the direct benefits. These 

secondary benefits are difficult to quantify in 

dollars, but must be considered. Secondary 

benefits are those that apply to the community as a 

whole. Examples include: 

• reduced interruption to business; 

• reduced potential for secondary damage (for 

example, fires) that could impact otherwise 

undamaged structures; 

• reduced potential for traffic flow problems 

around areas of significant damage; and 

• other reduced economic impacts. 

The process of selecting buildings to be 

rehabilitated begins with the determination of the 

cut-off Structural Score, S, below which detailed 

building seismic evaluation is required (e.g., by 

use of the FEMA 310 procedures). Such a 

determination allows estimates to be made on the 

costs of additional seismic evaluation and 

rehabilitation work. From this the benefits are 

determined. The most cost-effective solution will 

be the one where the least amount is spent in direct 

costs to gain the greatest direct and secondary 

benefits. 

After the RVS authority establishes the 

appropriate cut-off score and completes the 

screening process, it needs to determine the best 

way to notify building owners of the need for 

more review of buildings that score less than the 

cut-off (if the authority is not the owner of the 

buildings being screened). At the same time the 

community needs to develop the appropriate 

standards (for example, adoption of FEMA 356, 
46 4: Using the RVS Procedure Results FEMA-154 

Prestandard and Commentary on the Seismic 

Rehabilitation of Buildings [ASCE, 2000]) to 

accomplish the goal of the mitigation program. 

Ultimately, the mitigation program needs to 

address those buildings that represent the largest 

potential threat to life safety and the community. 

Timelines for compliance with the new standards 

and the mitigation program should be developed 

on a priority basis, such that the first priority 

actions relate to those buildings posing the most 

significant risk, after which those posing a lesser 

risk are addressed. 

4.4.2 Using RVS Data in Community 

Building Inventory Development 

RVS data can be used to establish building 

inventories that characterize a community’s 

seismic risk. For example, RVS data could be 

used to improve the HAZUS (NIBS, 1999) 

characterization of the local inventory, which has a 

default level based on population, economic 

factors, and regional trends. Similarly, RVS could 

be incorporated directly into a community’s 

Geographic Information System (GIS), allowing 

the community to generate electronic and paper 

maps that reflect the building stock of the 

community. Electronic color coding of the various 

types of buildings under the RVS authority, based 

on their ultimate vulnerability, allows the 

community to see at a glance where the vulnerable 

areas of the community are found. 

4.4.3 Using RVS Data to Plan Postearthquake Building-SafetyEvaluation Efforts 

In a postearthquake environment one of the initial 

response priorities is to determine rapidly the 

safety of buildings for continued occupancy. The 

procedure most often used is that represented in 

the ATC-20 Report, Procedures for 

Postearthquake Safety Evaluation of Buildings

(ATC, 1989, 1995). This procedure is similar in 

nature to that of the RVS procedure in that initial 

rapid evaluations are performed to find those 

buildings that are obviously unsafe (Red placard) 

and those that have no damage or damage that 

does not pose a threat to continued occupancy 

(Green placard). All other buildings fall into a 

condition where occupancy will need to be 

restricted in some form (Yellow placard). 

The database developed following the 

completion of the RVS process in a given 

community will be valuable in setting the 

priorities of where safety evaluation will be 

performed first, after a damaging earthquake. For 

example, a community could use HAZUS 

software, in combination with RVS-based 

inventory information, to determine areas where 

significant damage may exist for various 

earthquake scenarios. Similarly, a community 

could use an existing GIS containing RVS 

inventory data and computer-generated maps of 

strong ground shaking, such as the ShakeMaps 

developed by the USGS (ATC, in progress), to 

estimate the location and distribution of damaged 

buildings. With such information, community 

officials would be able to determine those areas 

where building safety evaluations should be 

conducted. 

Later, the data collected during the 

postearthquake building safety evaluations could 

be added to the RVS authority’s RVS-based 

building inventory database. Using GIS, maps can 

then be prepared showing the damage distribution 

within the community based on actual building 

damage. Building locations could be 

electronically color-coded in accordance with the 

color of the safety-evaluation placard that is 

placed on the building: Green, Yellow, or Red. 

4.4.4 Resources Needed for the Various 

Uses of the RVS Procedure 

For most applications of the RVS procedure, 

the resources needed to implement the process are 

similar, consisting principally of an RVS manager 

(the RVS authority), technical specialists to train 

screeners, a team of screeners, materials to be 

taken into the field (e.g., the Handbook and other 

items listed in Section 2.8), and building 

construction drawings. Most applications are 

assisted by the development and maintenance of a 

computerized database for recordkeeping and the 

use of geographic information systems (GIS). A 

matrix showing recommended resources for 

various FEMA 154 RVS applications is provided 

in Table 4-1. 
FEMA 154 4: Using the RVS Procedure Results 47 

Table 4-1 Matrix of Recommended Personnel and Material Resources for Various FEMA 154 RVS 

Applications* 

Resources 

Application 

RVS 

Manager 

RVS 

Trainer Screeners 

Screening 

Equipment 

and 

Supplies 

Building 

Drawings 

Computerized 

Record 

Keeping 

System GIS 

1. Ranking 

seismic 

rehabilitation 

needs 

X X X X X X X 

2. Designing 

seismic hazard 

mitigation 

programs 

X X X X X X X 

3. Developing 

inventories for 

regional 

earthquake 

damage and 

loss studies 

X X X X X X X 

4. Planning 

postearthquake 

building safety 

evaluation 

efforts 

X X X X X X X 

5. Developing 

building 

specific 

vulnerability 

information 

X X X X X 

 

*It is recommended that rapid visual screening projects be carried out under the oversight of a design professional 

with significant experience in seismic design. 

FEMA 154 5: Example Application of Rapid Visual Screening 49 

Chapter 5 

Example Application 

of Rapid Visual Screening 

Presented in this chapter is an illustrative 

application of the rapid visual screening procedure 

in the hypothetical community of Anyplace USA. 

The RVS implementation process (as depicted in 

Figure 2-1) is described, from budget development 

to selection of the appropriate Data Collection 

Form, to the screening of individual buildings in 

the field. Prior to implementation of the RVS 

procedure, the RVS authority (the Building and 

Planning Department of Anyplace) has reviewed 

the Handbook and established the purpose for the 

RVS. 

5.1 Step 1: Budget and Cost 

Estimation 

The RVS authority has been instructed by the city 

council to conduct the RVS process to identify all 

buildings in the city, excluding detached singlefamily and two-family dwellings, that are 

potentially earthquake hazardous and that should 

be further evaluated by a design professional 

experienced in seismic design (the principal 

purpose of the RVS procedure). It is understood 

that, depending on the results of the RVS, the city 

council may adopt future ordinances that establish 

policy on when, how and by whom low-scoring 

buildings should be evaluated and on future 

seismic rehabilitation requirements. It is also 

desired that the results from the RVS be 

incorporated in the geographic information system 

that the city recently installed to map and describe 

facilities throughout the city, including all 

buildings and utility systems within the city limits. 

The RVS authority has determined there are 

approximately 1,000 buildings in the city that are 

not detached single-family or two-family 

dwellings and that some of the buildings are at 

least 100 years old. The RVS authority plans 

(1) to conduct a pre-field data collection and 

evaluation process to examine and assess 

information in its existing files and to document 

building location, size, use, and other information 

on the Data Collection Forms prior to field 

screening; (2) to review available building plans 

prior to field screening; (3) to inspect the interiors 

of buildings whenever possible; (4) to establish an 

electronic RVS record-keeping system that is 

compatible with its GIS; and (5) to train screeners 

prior to sending them into the field. 

Costs to conduct these activities have been 

estimated, assuming an average of $40 per hour 

(salary plus benefits) for personnel who perform 

data evaluation, screening, and record 

management. Costs are in 2001 dollars. It is 

assumed that three persons will carry out the prefield data collection and evaluation process, that 

four two-person teams of design professionals will 

conduct the review of building plans and the field 

screening, that two persons will file all screening 

data, and that the entire RVS process will take 

approximately six months. Based on these rates 

and assumed times to conduct the various 

activities, the following RVS budget has been 

established: 

1. Pre-field data collection, evaluation, 

and processing (1,000 buildings × 

0.4 hr/building × $40/hr) $16,000 

2. Training, including trainer time 

(24 hours), screener time (8 hours 

per screener), and materials 4,000 

3. Review of available building plans 

(500 plan sets × 0.75 hr/plan set 

× $40/hr) 15,000 

4. Field screening (1,000 buildings 

× 0.75 hr/building × $40/hr) 30,000 

5. Record-keeping system 

development 5,000 

6. Electronic filing of Data Collection 

Forms, including verification of 

data input (1,000 forms × 

0.75 hour/form × $40/hour) 30,000

7. Subtotal $100,000 

8. Management (10% of item 7) 10,000

9. Total $110,000 
50 5: Example Application of Rapid Visual Screening FEMA 154 

5.2 Step 2: Pre-Field Planning 

During the pre-field planning process the RVS 

authority confirmed that the existing geographic 

information system was capable of being 

expanded to include RVS-related information and 

results. In addition, the RVS authority decided 

that sufficient soil information was available from 

the State Geologist to develop an overlay for their 

GIS containing soils information for the entire 

city. While not required as part of the RVS 

process, it was also determined that the city 

included an area that had isolated pockets of low 

liquefaction potential, and that there was no area 

with landslide potential. Consequently the RVS 

authority concluded that GIS overlays for liquefaction and landslide potential were not warranted. 

The RVS authority also verified that the 

existing GIS had reference tables containing 

address information for most of the properties in 

the city (developed earlier from the tax assessor’s 

files) and that these tables could be extracted and 

included in a new GIS-compatible electronic 

relational database containing the RVS results. It 

was also determined that other building and 

planning department’s files contained reliable 

information on building name, use, size (height 

and area), structural system, and age for buildings 

built or remodeled within the last 30 years, and 

that Sanborn maps, which contain size, age, and 

other building attribute information (see Section 

2.6.3) were available (at the local library) for most 

of the downtown sector. 

Based on this information, the RVS authority 

confirmed its prior preliminary decision under 

Step 1 to develop an electronic RVS record 

keeping system (relational database) that could be 

imported into the existing GIS. The RVS 

authority also decided to focus on the downtown 

sector of Anyplace during the initial phase of the 

RVS field work, and to expand to the outlying 

areas later. 

5.3 Step 3: Selection and Review of 

the Data Collection Form 

To choose the correct Data Collection Form, the 

RVS authority elected to establish the seismicity 

for Anyplace USA by using Method 2 (see Section 

2.4.1), rather than by selecting the seismicity 

region from the maps in Appendix A. Method 2, 

using the zip-code option, provides more precision 

than the Appendix A maps which use county 

boundaries. Method 2 was executed by accessing 

the USGS seismic hazard web site 

(http://geohazards.cr.usgs.gov/eq/), selecting 

Hazard by Zip Code, entering the zip code, 91234, 

and obtaining spectral acceleration (SA) values for 

0.2 second and 1.0 second for ground motions 

having a 2% probability of being exceeded in 50 

years (see Figure 5-1). The values of 2.10 g and 

0.88 g for 0.2 second and 1.0 second, respectively, 

were multiplied by 2/3 to obtain the reduced 

values of 1.40 g and 0.59 g, respectively, for 0.2 

The input zip-code is 91234. 

 ZIP CODE 91234 

 LOCATION 33.7754 Lat. -118.1860 Long. 

 DISTANCE TO NEAREST GRID POINT 3.0229 kms 

 NEAREST GRID POINT 33.8 Lat. -118.2 Long. 

 Probabilistic ground motion values, in %g, at the Nearest Grid 

 point are: 

 10%PE in 50 yr 5%PE in 50 yr 2%PE in 50 yr 

 PGA 51.809940 70.680931 96.476959 

 0.2 sec SA 118.997299 157.833496 210.003403 

 0.3 sec SA 114.200897 148.213104 194.634995 

 1.0 sec SA 42.566330 60.786320 88.084427 

Figure 5-1 Screen capture of USGS web page showing SA values for 0.2 sec and 1.0 sec for ground 

motions having 2% probability of being exceeded in 50 years (values shown in boxes).
FEMA 154 5: Example Application of Rapid Visual Screening 51 

second and 1.0 second. These reduced values were 

compared to the criteria in Table 2-1 to determine 

that the reduced (using the 2/3 factor) USGS 

assigned motions met the “high seismicity” criteria 

for both short-period and long-period motions 

(that is, 1.40 g is greater than 0.5 g for the 0.2 

second [short-period] motions, and 0.59 g is 

greater than 0.2 g for the 1.0 second [long-period] 

motions). All other zip codes in Anyplace were 

similarly input to the USGS web site, and the 

results indicated high seismicity in all cases. On 

this basis the RVS authority selected the Data 

Collection Form for high seismicity (Figure 5-2). 

Using the checklist of Table 2-3, the RVS 

authority reviewed the Data Collection Form to 

determine if the occupancy categories and 

occupancy loads were useful for their purposes 

and evaluated other parameters on the form, 

deciding that no changes were needed. The RVS 

authority also conferred with the chief building 

official, the department’s plan checkers, and local 

design professionals to establish key seismic code 

adoption dates for the various building lateralload-resisting systems considered by the RVS and 

for anchorage of heavy cladding. It was 

determined that Anyplace adopted seismic codes 

for W1, W2, S1, S5, C1, C3, RM1, and RM2 

building types in 1933, and that seismic codes 

were never adopted for URM buildings (after 1933 

they were no longer permitted to be built). For S2, 

S3, S4 and PC2 buildings, it was assumed for 

purposes of the RVS procedure that seismic codes 

were adopted in 1941, using the default year 

recommended in Section 2.4.2. For PC1 

buildings, it was assumed that seismic codes were 

first adopted in 1973 (per the guidance provided in 

Section 2.4.2). It was also determined that 

seismically rehabilitated URM buildings should be 

treated as buildings designed in accordance with a 

seismic code (that is, treated as if they were 

designed in 1933 or thereafter). Because Anyplace 

has been consistently adopting the Uniform 

Building Code since the early 1960s, benchmark 

years for all building types, except URM, were 

taken from the “UBC” column in Table 2-2. The 

year in which seismic anchorage requirements for 

heavy cladding was determined to be 1967. These 

findings were indicated on the Quick Reference 

Guide (See Figure 5-3). 

5.4 Step 4: Qualifications and 

Training for Screeners 

Anyplace USA selected RVS screeners from two 

sources: the staff of the Department of Building 

and Planning, and junior-level engineers from 

local engineering offices, who were hired on a 

temporary consulting basis. Training was carried 

out by one of the department’s most experienced 

plan checkers, who spent approximately 24 hours 

reading the FEMA 154 Handbook and preparing 

training materials. 

As recommended in this Handbook, the 

training was conducted in a classroom setting and 

consisted of: (1) discussions of lateral-forceresisting systems and how they behave when 

subjected to seismic loads; (2) how to use the Data 

Collection Form and the Quick Reference Guide; 

(3) a review of the Basic Structural Hazard Scores 

and Score Modifiers; (4) what to look for in the 

field; (5) how to account for uncertainty; and (6) 

an exercise in which screeners were shown interior 

and exterior photographs of buildings and asked to 

identify the lateral-load-resisting system and 

vertical and plan irregularities. The training class 

also included focused group interaction sessions, 

principally in relation to the identification of 

structural systems and irregularities using exterior 

and interior photographs. Screeners were also 

instructed on items to take into the field. 

5.5 Step 5: Acquisition and Review 

of Pre-Field Data 

As described in the Pre-Field Planning process 

(Step 2 above), the RVS authority of Anyplace 

USA already had electronic GIS reference tables 

containing street addresses and parcel numbers for 

most of the buildings in the city. These data 

(addresses and parcel numbers) were extracted 

from the electronic GIS system (see screen capture 

of GIS display showing parcel number and other 

available information for an example site, Figure 

5-4) and imported into a standard off-the-shelf 

electronic database as a table. To facilitate later 
52 5: Example Application of Rapid Visual Screening FEMA 154 

Figure 5-2 High seismicity Data Collection Form selected for Anyplace, USA. 
FEMA 154 5: Example Application of Rapid Visual Screening 53 

 Figure 5-3 Quick Reference Guide for Anyplace USA showing entries for years in which seismic codes were first 

adopted and enforced and benchmark years. 
54 5: Example Application of Rapid Visual Screening FEMA 154 

Figure 5-4 Property information at example site in city’s geographic information system. 

use in the GIS, the street addresses were 

subdivided into the following fields: the numeric 

part of the address; the street prefix (for example, 

“North”); the street name; and the street suffix (for 

example, “Drive”). A zip code field was added, 

zip codes for each street address were obtained 

using zip code lists available from the US Postal 

Service, and these data were also added to the 

database. This process yielded 950 street 

addresses, with parcel number and zip code, 

andestablished the initial information in 

Anyplace’s electronic “Building RVS Database”. 

Permitting files, which contained data on 

buildings constructed or remodeled within the last 

30 years (including parcel number), were then 

reviewed to obtain information on building name 

(if available), use, building height (height in feet 

and number of stories), total floor area, age (year 

built), and structural system. This process yielded 

information (from paper file folders) on 

approximately 500 buildings. Fields were added 

to the Building RVS Database for each of these 

attributes and data were added to the appropriate 

records (searching on parcel number) in the 

database; in the case of structure type, the entry 

included an asterisk to denote uncertainty. If an 

address was missing in the database, a new record 

containing that address and related data was 

added. On average, 30 minutes per building were 

required to extract the correct information from 

the permitting files and insert it into the electronic 

database. 

The city’s librarian provided copies of 

available Sanborn maps, which were reviewed to 

identify information on number of stories, year 

built, building size (square footage), building use, 

and limited information on structural type for 

approximately 200 buildings built prior to 1960. 

These data were added to the appropriate record 

(searching on address) in the Building RVS 

Database; in the case of structure type, the entry 

included an asterisk to denote uncertainty. If an 

address was missing in the database, a new record 

containing that address and related data was 

added. For this effort, 45 minutes per building, on 

average, were required to extract the correct 

information from the Sanborn maps and insert it 

into the electronic database.During the pre-field 

data collection and review process the RVS 

authority also obtained an electronic file of soils 

data (characterized in terms of the soil types 

described in Section 2.6.6) from the State 

Geologist and created an overlay of this 

information in the city’s GIS system. Points 

defined by the addresses in the GIS reference 

tables (including newly identified addresses added 

to the references tables as a result of the abovecited efforts) were combined with the soils type 

overlay, and soil type was then assigned to each 

point (address) by a standard GIS operating 
FEMA 154 5: Example Application of Rapid Visual Screening 55 

procedure. The soils type information for each 

address was then transferred back to the Building 

RVS Database table into a new field for each 

building’s soil type. 

Based on the above efforts, Anyplace’s 

Building RVS Database was expanded to include 

approximately 1,000 records with address, parcel 

number, zip code, and soils information, and 

approximately 700 of these records also contained 

information on building name (if any), use, 

number of stories, total floor area, year built, and 

structure type. 

5.6 Step 6: Review of Construction 

Documents 

Fortuitously, the city had retained microfilm 

copies of building construction documents 

submitted with each permit filing during the last 

30 years, and copies of these documents were 

available for 500 buildings (the same subset 

described in Step 5 above). Teams consisting of 

one building department staff member and one 

consulting engineer reviewed these documents to 

verify, or identify, the lateral-force-resisting 

system for each building. Any new or revised 

information on structure type derived as part of 

this process was then inserted in the Building RVS 

Database, in which case, previously existing 

information in this field, along with the associated 

asterisk denoting uncertainty, was removed. On 

average, this effort required approximately 30 

minutes per plan set, including database 

corrections. 

5.7 Step 7: Field Screening of 

Buildings 

Immediately prior to field screening (that is, at the 

conclusion of Step 6 above), the RVS authority 

acquired an electronic template of the Data 

Collection Form from the web site of the Applied 

Technology Council (www.atcouncil.org) and 

used this template to create individual Data 

Collection Forms for each record in the Building 

RVS Database. Each form contained unique 

information in the building identification portion 

of the form, with “Parcel Number” shown as 

“Other Identifiers” information (see Figure 5-2). 

In those instances where structure type 

information was included in the database, this 

information was also added as “Other Identifiers” 

information, with an asterisk if still uncertain. Soil 

type information was indicated on each form by 

circling the appropriate letter (and brief 

description) in the “Soil Type” section of the form 

(see Figure 5-2). 

The Data Collection Forms, including blank 

forms for use with buildings not yet in the 

Building RVS Database, were distributed to the 

RVS screeners along with their RVS assignments 

(on a block-by-block basis). Screeners were 

advised that some of the database information 

printed on the form (e.g., number of stories, 

structure type denoted with an *) would need to be 

verified in the field, that approximately 700 of the 

1,000 Data Collection Forms had substantially 

complete, but not necessarily verified, information 

in the location portion of the form, and that all 

1,000 forms had street, address, parcel number, zip 

code, and soil type information. 

Prior to field work, each screener was 

reminded to complete the Data Collection Form at 

each site before moving on to the next site, 

including adding his or her name as the screener 

and the screening date (in the building 

identification section of the form). 

Following are several examples illustrating 

rapid visual screening in the field and completion 

of the Data Collection Form. Some examples use 

forms containing relatively complete building 

identification information, including structure 

type, obtained during the pre-field data acquisition 

and review process (Step 5); others use forms 

containing less complete building identification 

information; and still others use blank forms 

completely filled in at the site. 

Example 1: 3703 Roxbury Street 

Upon arriving at the site the screeners 

observed the building as a whole (Figure 5-5) and 

began the process of verifying the information in 

the building identification portion of the form 

(upper right corner), starting with the street 

address. The building’s lateral-force-resisting 

system (S2, steel braced frame) was verified by 

looking at the building with binoculars (see Figure 

5-6). The number of stories (10), use (office), and 

year built (1986) were also confirmed by 

inspection. The base dimensions of the building 

were estimated by pacing off the distance along 

each face, assuming 3 feet per stride, resulting in 

the determination that it was 75 ft x 100 ft in plan. 
56 5: Example Application of Rapid Visual Screening FEMA 154 

On this basis, the listed square footage of 76,000 

square feet was verified as correct (see Figure 

5-7). The screeners also added their names and 

the date of the field screening to the building 

identification portion of the form. 

A sketch of the plan and elevation views of the 

building were drawn in the “Sketch” portion of the 

form. 

The building use was circled in the 

“Occupancy” portion, and from Section 3 of the 

Quick Reference Guide, the occupancy load was 

estimated at 75,000/150 = 500. Hence, the 

occupancy range of 101-1000 was circled. 

No falling hazards were observed, as glass 

cladding is not considered as heavy cladding. 

The next step in the process was to circle the 

appropriate Basic Structural Hazard Score and the 

appropriate Score Modifiers. Having verified the 

lateral-force-resisting system as S2, this code was 

circled along with the Basic Structural Score 

beneath it (see Figure 5-8). Because the building 

is high rise (8 stories or more) this modifier was 

circled. Noting that the soil is type D, as already 

determined during the pre-field data acquisition 

phase and indicated in the Soil Type portion of the 

form, the modifier for Soil Type D was circled. 

By adding the column of circled numbers, a Final 

Score of 3.2 was determined. Because this score 

was greater than the cut-off score of 2.0, the 

building did not require a detailed evaluation by an 

experienced seismic design professional. Lastly, 

an instant camera photo of the building was 

attached to the form. 

Figure 5-5 Exterior view of 3703 Roxbury Street.

Figure 5-6 Close-up view of 3703 Roxbury Street 

exterior showing perimeter braced steel

framing. 

Figure 5-7 Building identification portion of Data Collection Form for Example 1, 3703 Roxbury Street.
FEMA 154 5: Example Application of Rapid Visual Screening 57 

 Figure 5-8 Completed Data Collection Form for Example 1, 3703 Roxbury Street.
58 5: Example Application of Rapid Visual Screening FEMA 154 

Example 2: 3711 Roxbury Street 

Upon arrival at the site, the screeners observed the 

building as a whole (Figure 5-9). Unlike Example 

1, there was little information in the building 

identification portion of the form (only street 

address, zip code, and parcel number were 

provided). The screeners determined the number 

of stories to be 12 and the building use to be 

commercial and office. They paced off the 

building plan dimensions to estimate the plan size 

to be 58 feet x 50 feet. Based on this information, 

the total square footage was estimated to be 

34,800 square feet (12 x 50 x 58), and the number 

of stories, use, and square footage were written on 

the form. Based on a review of information in 

Appendix D of this Handbook, the year of 

construction was estimated to be 1944 and this 

date was written on the form. 

A sketch of the plan and elevation views of the 

building were drawn in the “Sketch” portion of the 

form. 

The building use was circled in the 

“Occupancy” portion, and from Section 3 of the 

Quick Reference Guide, the occupancy load was 

estimated at 34,800/135♦ = 258. Hence, the 

occupancy range of 101-1000 was circled. 

The cornices at roof level were observed, and 

entered on the form. 

Noting that the estimated construction date 

was 1944 and that it was a 12-story building , a 

review of the material in Table D-6 (Appendix D), 

indicated that the likely options for building type 

were S1, S2, S5, C1, C2, or C3. On more careful 

examination of the building exterior with the use 

of binoculars (see Figure 5-10), it was determined 

the building was type C3, and this alpha-numeric 

code, and accompanying Basic Structural Score, 

were circled on the Data Collection Form. 

Because the building was high-rise (more than 

7 stories), this modifier was circled, and because 

the four individual towers extending above the 

base represented a vertical irregularity, this 

modifier was circled. Noting that the soil is type 

D, as already determined during the pre-field data 

acquisition phase and indicated in the Soil Type 

portion of the form, the modifier for Soil Type D 

was circled. 

By adding the column of circled numbers, a 

Final Score of 0.5 was determined. Because this 

score was less than the cut-off score of 2.0, the 

building required a detailed evaluation by an 

experienced seismic design professional. Lastly, 

 

♦ The “135” value is the approximate average of the 

mid-range occupancy load for commercial buildings 

(125 sq. ft. per person) and the mid-range occupancy 

load for office buildings (150 sq. ft. per person). 

an instant camera photo of the building was 

attached to the Data Collection Form (a completed 

version of the form is provided in Figure 5-11). 

Figure 5-9 Exterior view of 3711 Roxbury. 

Figure 5-10 Close-up view of 3711 Roxbury 

Street building exterior showing 

infill frame construction. 
FEMA 154 5: Example Application of Rapid Visual Screening 59 

 Figure 5-11 Completed Data Collection Form for Example 2, 3711 Roxbury Street.
60 5: Example Application of Rapid Visual Screening FEMA 154 

Example 3: 5020 Ebony Drive 

Example 3 was a high-rise residential building 

(Figure 5-12) in a new part of the city in which 

new development had begun within the last few 

years. The building was not included in the 

electronic Building RVS Database, and 

consequently there was not a partially prepared 

Data Collection Form for this building. Based on 

visual inspection, the screeners determined that the 

building had 22 stories, including a tall-story 

penthouse, estimated that it was designed in 1996, 

and concluded that its use was both commercial 

(in the first story) and residential in the upper 

stories. The screeners paced off the building plan 

dimensions to estimate the plan size to be 

approximately 270 feet x 180 feet. Based on this 

information and considering the symmetric but 

non-rectangular floor plan, the total square footage 

was estimated to be 712,800 square feet. These 

data were written on the form, along with the 

names of the screeners and the date of the 

screening. The screeners also drew a sketch of a 

portion of the plan view of the building in the 

space on the form allocated for a “Sketch”. 

The building use (commercial and residential) 

was circled in the “Occupancy” portion, and from 

Section 3 of the Quick Reference Guide, the 

occupancy load was estimated at 712,800/200 = 

3,564. Based on this information, the occupancy 

range of 1000+ was circled. 

While the screeners reasonably could have 

assumed a type D soil, which was the condition at 

the adjacent site approximately 1⁄2 mile away, they 

concluded they had no basis for assigning a soil 

type. Hence they followed the instructions in the 

Handbook (Section 3.4), which specifies that if 

there is no basis for assigning a soil type, soil type 

E should be assumed. Accordingly, this soil type 

was circled on the form. 

Given the design date of 1996, the anchorage 

for the heavy cladding on the exterior of the 

building was assumed to have been designed to 

meet the anchorage requirements initially adopted 

in 1967 (per the information on the Quick 

Reference Guide). No other falling hazards were 

observed. 

The window spacing in the upper stories and 

the column spacing at the first floor level indicated 

the building was either a steel moment-frame 

building, or a concrete moment-frame building. 

The screeners attempted to view the interior but 

were not provided with permission to do so. They 

elected to indicate that the building was either an 

S1 or C1 type on the Data Collection Form and 

circled both types, along with their Basic 

Structural Scores. In addition, the screeners 

circled the modifiers for high rise (8 stories or 

more) and post-benchmark year, given that the 

estimated design date (1996) occurred after the 

benchmark years for both S1 and C1 building 

types (per the information on the Quick Reference 

Guide). They also circled the modifier for soil 

type E (in both the S1 and C1 columns). 

By adding the circled numbers in both the S1 

and C1 columns, Final Scores of 3.6 and 3.3 

respectively were determined for the two building 

types. Because both scores were greater than the 

cut-off score of 2.0, a detailed evaluation of the 

building by an experienced seismic design 

professional was not required. Before leaving the 

site, the screeners photographed the building and 

attached the photo to the Data Collection Form. A 

completed version of the Data Collection Form is 

provided in Figure 5-13. 

Figure 5-12 Exterior view of 5020 Ebony Drive.
FEMA 154 5: Example Application of Rapid Visual Screening 61 

Figure 5-13 Completed Data Collection Form for Example 3, 5020 Ebony Drive. 
62 5: Example Application of Rapid Visual Screening FEMA 154 

Figure 5-15 Building identification portion of Data Collection Form for Example 4, 1450 Addison Avenue.

Example 4: 1450 Addison Avenue 

The building at 1450 Addison Avenue (see Figure 

5-14) was a 1-story commercial building designed 

in 1990, per the information provided in the 

building identification portion of the Data 

Collection Form. By inspection the screeners 

confirmed the address, number of stories, use 

(commercial), and year built (Figure 5-15). The 

screeners paced off the building plan dimensions 

to estimate the plan size (estimated to be 10,125 

square feet), confirming the square footage shown 

on the identification portion of the form. The Lshaped building was drawn on the form, along 

with the dimensions of the various legs. 

The building’s commercial use was circled in 

the “Occupancy” portion, and from Section 3 of 

the Quick Reference Guide, the occupancy load 

was estimated at 10,200/125 = 80. Hence, the 

occupancy range of 11-100 was circled. No falling 

hazards were observed. 

The building type (W2) was circled on the 

form along with its Basic Structural Score. 

Because the building was L-shaped in plan the 

modifier for plan irregularity was circled. Because 

soil type C had been circled in the Soil Type box 

(based on the information in the Building RVS 

Database) the modifier for soil type C was circled. 

By adding the column of circled numbers, a 

Final Score of 5.3 was determined. Because this 

score was greater than the cut-off score of 2.0, the 

building did not require a detailed evaluation by an 

experienced seismic design professional. Lastly, 

an instant camera photo of the building was 

attached to the Data Collection Form. A 

completed version of the form is provided in 

Figure 5-16. 

Figure 5-14 Exterior view of 1450 Addison Avenue.
FEMA 154 5: Example Application of Rapid Visual Screening 63 

Figure 5-16 Completed Data Collection Form for Example 4, 1450 Addison Avenue.
64 5: Example Application of Rapid Visual Screening FEMA 154 

5.8 Step 8: Transferring the RVS 

Field Data to the Electronic 

Building RVS Database 

The last step in the implementation of rapid visual 

screening for Anyplace USA was transferring the 

information on the RVS Data Collection Forms 

into the relational electronic Building RVS 

Database. This required that all photos and 

sketches on the forms be scanned and numbered 

(for reference purposes), and that additional fields 

(and tables) be added to the database for those 

attributes not originally included in the database. 

For quality control purposes, data were 

entered separately into two different versions of 

the electronic database, except photographs and 

sketches, which were scanned only once. A 

double-entry data verification process was then 

used, whereby the data from one database were 

compared to the same entries in the second 

database to identify those entries that were not 

exactly the same. Non-identical entries were 

examined and corrected as necessary. The entire 

process, including scanning of sketches and 

photographs, required approximately 45 minutes 

per Data Collection Form. 

After the electronic Building RVS Database 

was verified, it was imported into the city’s GIS, 

thereby providing Anyplace with a state-of-the-art 

capability to identify and plot building groups 

based on any set of criteria desired by the city’s 

policy makers. Photographs and sketches of 

individual buildings could also be shown in the 

GIS simply by clicking on the dot or symbol used 

to represent each building and selecting the 

desired image. 
FEMA 154 A: Maps Showing Seismicity Regions 65

Appendix A

Maps Showing

Seismicity Regions
66 A: Maps Showing Seismicity Regions FEMA 154

Figure A-1 Seismicity Regions of the Conterminous United States.
FEMA 154 A: Maps Showing Seismicity Regions 67

Figure A-2 Seismicity Regions in California, Idaho, Nevada, Oregon, and Washington.
68 A: Maps Showing Seismicity Regions FEMA 154

Figure A-3 Seismicity Regions in Arizona, Montana, Utah, and Wyoming.
FEMA 154 A: Maps Showing Seismicity Regions 69

Figure A-4 Seismicity Regions in Colorado, Kansas, New Mexico, Oklahoma,

and Texas.
70 A: Maps Showing Seismicity Regions FEMA 154

Figure A-5 Seismicity Regions in Iowa, Michigan, Minnesota, Nebraska, North Dakota, South Dakota, 

and Wisconsin.
FEMA 154 A: Maps Showing Seismicity Regions 71

Figure A-6 Seismicity Regions in Illinois, Indiana, Kentucky, Missouri, and Ohio.
72 A: Maps Showing Seismicity Regions FEMA 154

Figure A-7 Seismicity Regions in Alabama, Arkansas, Louisiana, Mississippi, 

and Tennessee.
FEMA 154 A: Maps Showing Seismicity Regions 73

Figure A-8 Seismicity Regions in Connecticut, Maine, Massachusetts, 

New Hampshire, New York, Rhode Island, and Vermont.
74 A: Maps Showing Seismicity Regions FEMA 154

Figure A-9 Seismicity Regions in Delaware, Maryland, New Jersey, 

Pennsylvania, Virginia, and West Virginia.
FEMA 154 A: Maps Showing Seismicity Regions 75

Figure A-10 Seismicity Regions in Florida, Georgia, North Carolina, and 

South Carolina.
76 A: Maps Showing Seismicity Regions FEMA 154

Figure A-11 Seismicity Regions in Alaska and Hawaii.
FEMA 154 B: Data Collection Forms and Quick Reference Guide 77

Appendix B

Data Collection Forms and

Quick Reference Guide





FEMA 154 C: Review of Design and Construction Drawings 83

Appendix C

Review of Design and

Construction Drawings

Drawing styles vary among engineering offices, but 

the conventions used are very consistent. The following are some of the common designations:

1. Around the perimeter of the building, the exterior 

walls will be shown as a double line, if the space 

between the lines is empty, this will usually be a 

wood stud wall.

2. Concrete walls will be shaded.

3. Masonry walls will be cross hatched.

4. Horizontal beams and girders will be shown with 

a solid line for steel and wood, and a double solid 

or dotted line for concrete.

● Steel framing will have a notation of shape, 

depth, and weight of the member. The designations will include W, S, I, B and several 

others followed by the depth in inches, an 

“x,” and the weight in pounds per lineal foot. 

An example would be W8x10 (wide flange 

shape, 8” deep, 10 lbs/ft).

● Wood framing will have the width and depth 

of the member. An example would be 4x10 

(4” wide and 10” deep). Floor joists and roof 

rafters will be shown with the same call-out 

except not all members will be shown. A 

few at each end of the area being framed will 

show and there will be an arrow showing the 

extent and the call-out of the size members.

● Concrete framing will have the width and 

depth. Where steel and wood are shown as 

single line, concrete will be shown as a double line. An example of the call out would 

be 12x24 (12” wide and 24” deep). Additionally, or in lieu of the number call-out, the 

member might be given a letter and number 

(B-1 or G-1) with a reference to a schedule 

for the size and reinforcing. “B” stands for 

beam and “G” stands for girder. Usually, 

beams are smaller than girders and span 

between girders while girders will be larger 

and frame between columns.

5. Columns will show on the floor plans as their 

shape with a shading designation where appropriate:

● Steel column will be shown as an “H” 

rotated to the correct orientation for the location on the plan.

● Wood column will be an open square.

● Concrete column will be either a square or a 

circle depending on the column configuration. The square or circle will be 

shaded.

6. Steel moment frames will show the columns with 

a heavy line between the columns representing 

the beam or girder. At each end of the beam or 

girder at the column will be a small triangle 

shaded. This indicates that the connection 

between the beam or girder and the column is 

fully restrained.

FEMA 154 D: Exterior Screening for Seismic System and Age 85

Appendix D

Exterior Screening for Seismic

System and Age

D.1 Introduction

A successful evaluation of a building is dependent on 

the screener’s ability to identify accurately the construction materials, lateral-force-resisting system, 

age, and other attributes that would modify its earthquake performance (e.g., vertical or plan irregularities). This appendix includes discussions of 

inspection techniques that can be used while viewing 

from the street.

D.2 What to Look for and How to Find It

It may be difficult to identify positively the structural 

type from the street as building veneers often mask 

the structural skeleton. For example, a steel frame 

and a concrete frame may look similar from the outside. Features typical of a specific type of structure 

may give clues for successful identification. In some 

cases there may be more than one type of frame 

present in the structure. Should this be the case, the 

predominant frame type should be indicated on the 

form.

Following are attributes that should be considered when trying to determine a building lateralforce-resisting system from the street:

1. Age: The approximate age of a building can indicate the possible structure type, as well as indicating the seismic design code used during the 

building design process. Age is difficult to determine visually, but an approximation, accurate 

within perhaps a decade, can be estimated by 

looking at the architectural style and detail treatment of the building exterior, if the facade has 

not been renovated. If a building has been renovated, the apparent age is misleading. See Section D.3 for additional guidance.

2. Facade Pattern: The type of structure can sometimes be deduced by the openness of the facade, 

or the size and pattern of window openings. The 

facade material often can give hints to the structure beneath. Newer facade materials likely indicate that modern construction types were used in 

the design and may indicate that certain building 

types can be eliminated.

3. Height: The number of stories will indicate the 

possible type of construction. This is particularly 

useful for taller buildings, when combined with 

knowledge of local building practice. See Section D.4 for additional guidance.

4. Original Use: The original use can, at times, give 

hints as to the structural type. The original use 

can be inferred from the building character, if the 

building has not been renovated. The present use 

may be different from the original use. This is 

especially true in neighborhoods that have 

changed in character. A typical example of this is 

where a city’s central business district has grown 

rapidly, and engulfed what were once industrial 

districts. The buildings’ use has changed and 

they are now either mixed office, commercial or 

residential (for office workers).

D.3 Identification of Building Age

The ability to identify the age of a building by considering its architectural style and construction materials requires an extensive knowledge of architectural 

history and past construction practice. It is beyond 

the scope of this Handbook to discuss the various 

styles and construction practices. Persons involved in 

or interested in buildings often have a general knowledge of architectural history relevant to their region. 

Interested readers should refer to in-depth texts for 

more specific information.

Photographs, architectural character, and age of 

(1) residential, (2) commercial, and (3) mixed use 

and miscellaneous buildings, are illustrated in 

Tables D-1 through D-3, respectively. Photographs 

of several example steel frame and concrete frame 

buildings under construction are provided in 

Figure D-1. The screener should study these photographs and characteristics closely to assist in differentiating architectural styles and facade treatment of 

various periods. Facade renovation (see photos b and 

c in Figure D-1) can clearly alter the original appearance. When estimating building age, the screener 

should look at the building from all sides as facade 

renovation often occurs only at the building front. A 

new building will seldom look like an old one. That 
86 D: Exterior Screening for Seismic System and Age FEMA 154

Table D-1 Photographs, Architectural Characteristics, and Age of Residential Buildings

Examples Characteristics

a. 1965-1980

c. 1965-1980

e. Pre-1933 URM (rehabilitated)

b. 1965-1980

d. 1960-1975 reinforced concrete 

shear wall

Low-Rise Buildings

(1-3 stories):

● Typically wood or 

masonry

● May have ground 

floor or basement 

parking, a soft story

● Older buildings typically have more 

architectural detail, 

ornamentation

● 1950s and later are 

more ‘modern’ − 

lacking ornamentation, typically with 

more horizontal 

lines

Common structural 

types: W2, RM1, RM2, 

URM

Mid-Rise (4-7 stories) and High-Rise 

Buildings (8 stories 

and higher):

● Typically, reinforced concrete 

(older, URM)

● May have commercial ground floor, a 

soft story

● Older buildings typically have more 

cornices, architectural detail, ornamentation

● 1950s and later are 

lacking ornamentation, typically with 

stronger vertical or 

horizontal lines

Common structural 

types: W2, RM1, RM2, 

URM
FEMA 154 D: Exterior Screening for Seismic System and Age 87

Table D-2 Illustrations, Architectural Characteristics, and Age of Commercial Structures

Examples Characteristics

a. Pre-1930

c. 1920-1930

b. 1910-1920

(Steel frame with unreinforced masonry 

infill that has been seismically 

rehabilitated)

d. 1920-1930

e. 1890-1900

Pre-1950

● Building has flat roof with 

cornices, or several setbacks.

● Ornate decorative work in 

concrete, terra cotta, cast 

stone or iron.

● Large bell tower or clock 

tower is common.

● Simple pattern of windows on all sides.

● Floors are concrete slabs 

on steel or concrete 

beams.

● Exterior is stone, terra 

cotta or concrete.

Common Structure Types:

S2, S5, C2, C3
88 D: Exterior Screening for Seismic System and Age FEMA 154

f. 44 story, 1960s, L-shape on the left;

20 story, 1914, with setback on 

the right

h. 1940-1950

g. 1950-1975

i. 1950-1975

j. 1950-1975

1950-1975

● Flat roof, typically with no 

cornice.

● Building is square or rectangular full height, fewer 

setbacks.

● First story and top story 

can be taller than other 

stories. In some cases the 

top story could be shorter 

than others.

● Exterior finishes metal or 

glass, pre-cast stone or 

concrete.

● Floors are concrete slab 

over steel or concrete 

beams.

Common Structure Types:

S1, S2, S4, C1, C2

Table D-2 Illustrations, Architectural Characteristics, and Age of Commercial Structures (Continued)

Examples Characteristics
FEMA 154 D: Exterior Screening for Seismic System and Age 89

is, a building is usually at least as old as it looks. 

Even when designed to look old, telltale signs of 

modern techniques can usually be seen in the type of 

windows, fixtures, and material used.

D.4 Identification of Structural Type

The most common inspection that will be utilized 

with the RVS procedure will be the exterior or “sidewalk” or “streetside” survey. First, the evaluation 

should be as thorough as possible and performed in a 

logical manner. The street-facing front of the building is the starting point and the evaluation begins at 

the ground and progressively moves up the exterior 

wall to the roof or parapet line. For taller buildings, a 

pair of binoculars is useful. When a thorough inspection of the street-front elevation has been completed, 

the procedure is repeated on the next accessible wall.

From the exterior, the screener should be able to 

determine the approximate age of the building, its 

original occupancy, and count the number of stories. 

k. Post-1975

m. Post-1975

l. Post-1975

n. Post-1975

Post-1975

● Flat roof, typically with no 

cornice.

● Building is square or rectangular for its full height, 

fewer setbacks.

● First story and top story 

can be taller than other 

stories. (In some cases, 

though, the top story 

could be shorter than others.)

● Exterior finishes: metal or 

glass, pre-cast stone or 

concrete, with little ornamentation

● Floors are concrete slabs 

over steel or concrete 

beams.

Common Structure Types:

S1, S2, S4, C1, C2

o. Post-1975

Table D-2 Illustrations, Architectural Characteristics, and Age of Commercial Structures (Continued)

Examples Characteristics
90 D: Exterior Screening for Seismic System and Age FEMA 154

Table D-3 Photographs, Architectural Characteristics, and Age of Miscellaneous Structures

Examples Characteristics

a. 1920-1930

c. 1990-2000

d. 1990-2000; airport terminal

b. 1920-1950

 e. 1920-1930; windows create 

coupled shear walls.

Mixed use (residential with a 

commercial first floor), places 

of assembly, theatres, triangular 

buildings, halls, parking structures:

● Long spans

● Tall first story (for commercial use) − soft or weak story

● Atria or irregular floor-tofloor layout

f. Pre-1930

g. 1950 − 1965 parking 

structure

 h. 1920-1930; theater and shops complex, reinforced concrete
FEMA 154 D: Exterior Screening for Seismic System and Age 91

With this information, Tables D-4 through D-7 provide the most likely structural system type, based on 

original occupancy and number of stories. (These 

tables are based on expert judgment and would benefit from verification by design professionals and 

building regulatory personnel familiar with local 

design and construction practices.) 

In addition to using information on occupancy 

and number of stories, as provided in Tables D-4 

through D-7, the following are some locations that 

a. Building above is a high-rise steel dual system −

moment frame (heavy columns and beams on upper 

facade) with bracing around elevator core. Fireproofing is being applied to steel at mid-height (inside the 

shroud) and precast facade elements are being 

attached to frame in lower stories.

b. Reinforced concrete frame under renovation − demolition of older facade units.

 c. New precast facade units being applied to reinforced concrete frame buildings.

Figure D-1 Photos showing basic construction, in steel-frame buildings and reinforced concrete-frame 

buildings.
92 D: Exterior Screening for Seismic System and Age FEMA 154

Table D-4 Most Likely Structural Types for Pre-1930 Buildings

Number of Stories

Original Occupancy 1-2 3 4-6 7-15 15-30 30+

 Residential W W S5 S5

URM URM C3 C3

URM

 Commercial W W S1 S1 S1

S4 S4 S2 S2 S2

S5 S5 S4 S4 S4

C1 C1 S5 S5 S5

C2 C2 C1 C1 C1

C3 C3 C2 C2 C2

URM URM C3 C3 C3

URM

 Industrial W W

S1 S1

S2 S2

S3 S5

S5 C1

C1 C2

C2 C3

C3 URM

URM

Note: If it is not possible to identify immediately the structural type for a pre-1930 building, the original occupancy 

and number of stories will provide some guidance. The building will need further inspection for precise identification.

Table D-5 Most Likely Structural Types for 1930-1945 Buildings

Number of Stories

Original Occupancy 1-2 3 4-6 7-15 15-30 30+

 Residential W W S1 S1

URM URM S2 S2

S5 S5

URM

 Commercial W W S1 S1 S1 S2

S1 S1 S2 S2 S2 S5

S2 S2 S5 S5 S5

S5 S5 C1 C1 C1

C1 C1 C2 C2 C2

C2 C2 C3 C3 C3

C3 C3 RM1

RM1 RM1 RM2

RM2 RM2 URM

URM URM

 Industrial S3 S3 C1

S5 S5 C2

C1 C1 C3

C2 C2

C3 C3

RM1 RM1

RM2 RM2

URM URM

Note: If it is not possible to identify immediately the structural type for a 1930-1945 building, the original occupancy and number of stories will provide some guidance. The building will need further inspection for precise 

identification.
FEMA 154 D: Exterior Screening for Seismic System and Age 93

Table D-6 Most Likely Structural Types for 1945-1960 Buildings

Number of Stories

Original Occupancy 1-2 3 4-6 7-15 15-30 30+

 Residential W W S1 S1 S1 S1

RM RM S2 S2 S2 S2

URM* URM* C1 C1 C1 C1

C2 C2 C2 C2

RM1,2

URM*

 Commercial W W S1 S1 S1 S1

S1 S1 S2 S2 S2 S2

S2 S2 C1 C1 C1 C1

C1 C1 C2 C2 C2 C2

C2 C2 RM1

RM1,2 RM1,2 RM2

URM* URM* URM*

 Industrial C1 S1 S1

C2 S2 S2

PC1 C1 C1

RM1 C2 C2

RM2 RM1,2 RM1,2

URM* URM* URM*

Notes: If it is not possible to identify immediately the structural type for a 1945-1960 building, the original occupancy and number of stories will provide some guidance. The building will need further inspection for precise identification.

*By this period, URM was generally not permitted in California or other high-seismicity locations, so that 

only in the central or eastern U.S. would buildings of this age be URM.

Table D-7 Most Likely Structural Types for Post-1960 Buildings

Number of Stories

Original Occupancy 1-2 3 4-6 7-15 15-30 30+

 Residential W W W S1

S1 S1 S1 S2

S2 S2 S2 C1

C1 C1 C1 C2

C2 C2 C2 PC2

PC2 PC2 PC2 RM1

RM1,2 RM1,2 RM1,2 RM2

 Commercial W W W S1 S1 S1

S1 S1 S1 S2 S2 S2

S2 S2 S2 C1 C1 C1

C1 C1 C1 C2 C2 C2

C2 C2 C2 PC2 PC2

PC1 PC1 PC2 RM1

PC2 PC2 RM1 RM2

RM1,2 RM1,2 RM2

 Industrial S1 S1 S1 S1 C1

S2 S2 S2 S2 C2

S3 C1 C1 C1 PC2

C1 C2 C2 C2

C2 PC1 PC2 PC2

PC1 PC2 RM1

PC2 RM1 RM2

RM1,2 RM2

Note: If it is not possible to identify immediately the structural type for a post-1960 building, the original occupancy 

and number of stories will provide some guidance. The building will need further inspection for precise identification.
94 D: Exterior Screening for Seismic System and Age FEMA 154

the screener can look, without performing destructive 

investigations, to gain insight into the structure type: 

1. In newer frame construction the columns are 

often exposed on the exterior in the first story. If 

the columns are covered with a facade material, 

they are most likely steel columns, indicating a 

steel frame. If the frames are concrete, they are 

usually exposed and not covered with a facade. 

See Figures D-2 and D-3.

2. Some structures use a combination of shear walls 

in the transverse direction and frames in the longitudinal direction. This can be seen from the 

exterior as the shear walls usually extend through 

the exterior longitudinal wall and are exposed 

there. This is most common in hotels and other 

residential structures where balconies are 

included. See Figure D-4.

3. An inspection of doorways and window framing 

can determine wall thickness. When the thickness exceeds approximately 12 inches, the wall is 

most likely unreinforced masonry (URM). 

4. If there are vertical joints in the wall, regularly 

spaced and extending to the full height, the wall 

is constructed of concrete, and if three or less stories in height, the structure type is most likely a 

tilt-up (PC1). See Figure D-5.

5. If the building is constructed of brick masonry 

without header courses (horizontal rows of visible brick ends), and the wall thickness is approximately 8 inches, the structural type is most 

likely reinforced masonry (RM1 or RM2). See 

Figure D-6.

6. If the exterior wall shows large concrete block 

units (approximately 8 to 12 inches high and 12 

to 16 inches in length), either smooth or rough 

faced, the structure type may be reinforced concrete block masonry. See Figure D-7.

Because many buildings have been renovated, the 

screener should know where to look for clues to the 

original construction. Most renovations are done for 

commercial retail spaces, as businesses like to have 

an up-to-date image. Most exterior renovations are 

only to the front of the building or to walls that 

attract attention. Therefore, the original construction 

Figure D-2 Building with exterior columns covered 

with a facade material.

Figure D-3 Detail of the column facade of Figure D-2.

Figure D-4 Building with both shear walls (in the 

short direction) and frames (in the long 

direction).
FEMA 154 D: Exterior Screening for Seismic System and Age 95

can often be seen at the sides, or the rear, where people generally do not look. If the original material is 

covered in these areas, it is often just painted or 

lightly plastered. In this case, the pattern of the older 

material can often still be seen.

Clues helping identify the original material are 

apparent if one is looking for them. Two examples 

are included here:

● Figure D-8 shows a building with a 1970s polished stone and glass facade. The side of the 

building indicates that it is a pre-1930 URM 

bearing-wall structure. 

● Figure D-9 shows a building facade with typical 

1960s material. The side was painted. Showing 

through the paint, the horizontal board patterns in 

the poured-in-place concrete wall of pre-1940 

construction could still be seen.

D.5 Characteristics of Exposed Construction Materials

Accurate identification of the structural type often 

depends on the ability to recognize the exposed construction material. The screener should be familiar 

Figure D-5 Regular, full-height joints in a building’s 

wall indicate a concrete tilt-up.

Figure D-6 Reinforced masonry wall showing no 

course of header bricks (a row of visible 

brick ends).

Figure D-7 Reinforced masonry building with 

exterior wall of concrete masonry units, or 

concrete blocks.

Figure D-8 A 1970s renovated facade hides a URM 

bearing-wall structure.
96 D: Exterior Screening for Seismic System and Age FEMA 154

with how different materials look on existing buildings as well as how they have been installed. Brief 

descriptions of some common materials are included 

here:

● Unreinforced Masonry—Unreinforced masonry 

walls, when they are not veneers, are typically 

several wythes thick (a wythe is a term denoting 

the width of one brick). Therefore, header bricks 

will be apparent in the exposed surface. Headers 

are bricks laid with the butt end on the exterior 

face, and function to tie wythes of bricks 

together. Header courses typically occur every 

six or seven courses. (See Figures D-10 and 

D-11.) Sometimes, URM infill walls will not 

have header bricks, and the wythes of brick are 

held together only by mortar. Needless to say, 

URM will look old, and most of the time show 

wear and weathering. URM may also have a soft 

sand-lime mortar which may be detected by 

scratching with a knife, unless the masonry has 

been repointed.

● Reinforced Masonry—Most reinforced brick 

walls are constructed using the hollow grout 

method. Two wythes of bricks are laid with a 

hollow space in between. This space contains the 

reinforcement steel and is grouted afterward (see 

Figure D-12). This method of construction usually does not include header bricks in the wall 

surface. 

● Masonry Veneer—Masonry veneers can be of 

several types, including prefabricated panels, 

thin brick texture tiles, and a single wythe of 

brick applied onto the structural backing. 

Figures D-13 shows brick veneer panels. Note 

the discontinuity of the brick pattern interrupted 

by the vertica1 gaps. This indicates that the surface is probably a veneer panel. The scupper 

opening at the top of the wall, probably to let the 

rainwater on the roof to drain, also indicates that 

this is a thin veneer rather than a solid masonry 

Figure D-9 A concrete shear-wall structure with a 

1960s renovated facade.

Figure D-10 URM wall showing header courses 

(identified by arrows) and two washer 

plates indicating wall anchors.

Figure D-11 Drawing of two types of masonry pattern showing header bricks (shown with stipples).
FEMA 154 D: Exterior Screening for Seismic System and Age 97

wall. Good places to look for the evidence of 

veneer tile are at door or window openings where 

the edge of the tile will usually show. 

● Hollow Clay Tile—The exposed area of a hollow 

clay tile masonry unit is approximately 6 inches 

by 10 inches and often has strip indentations running the length of the tile. They are fragile, unreinforced, and without structural value, and 

usually are used for non-load-bearing walls. 

Figure D-14 shows a typical wall panel which 

has been punctured.

● False Masonry—Masonry pattern sidings can be 

made from sheet metal, plastic, or asphalt material (see Figures D-15 and D-16). These sidings 

come in sheets and are attached to a structural 

backing, usually a wood frame. These sidings 

can be detected by looking at the edges and by 

their sound when tapped.

● Cast-in-Place Concrete—Cast-in-place concrete, 

before the 1940s, will likely show horizontal patterns from the wooden formwork. The formwork 

was constructed with wood planks, and therefore 

the concrete also will often show the wood grain 

pattern. Since the plank edges were not smooth, 

Figure D-12 Diagram of common reinforced masonry 

construction. Bricks are left out of the 

bottom course at intervals to create 

cleanout holes, then inserted before 

grouting.

Figure D-13 Brick veneer panels.

Figure D-14 Hollow clay tile wall with punctured tile.

Figure D-15 Sheet metal siding with masonry pattern.
98 D: Exterior Screening for Seismic System and Age FEMA 154

the surface will have horizontal lines approximately 4, 6, 8, 10, or 12 inches apart (see 

Figure D-17). Newer cast-in-place concrete 

comes in various finishes. The most economic 

finish is that in which the concrete is cast against 

plywood formwork, which will reflect the wood 

grain appearance of plywood, or against metal or 

plastic-covered wood forms, which normally do 

not show a distinctive pattern. 

Figure D-16 Asphalt siding with brick pattern.

Figure D-17 Pre-1940 cast-in-place concrete with 

formwork pattern.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 99

Appendix E

Characteristics and Earthquake

Performance of RVS Building Types

E.1 Introduction

For the purpose of the RVS, building structural framing types have been categorized into fifteen types 

listed in Section 3.7.1 and shown in Table 3-1. This 

appendix provides additional information about each 

of these structural types, including detailed descriptions of their characteristics, common types of earthquake damage, and common seismic rehabilitation 

techniques.

E.2 Wood Frame (W1, W2)

E.2.1 Characteristics

Wood frame structures are usually detached residential dwellings, small apartments, commercial buildings or one-story industrial structures. They are 

rarely more than three stories tall, although older 

buildings may be as high as six stories, in rare 

instances. (See Figures E-1 and E-2)

Wood stud walls are typically constructed of 2-

inch by 4-inch wood members vertically set about 16 

inches apart. (See Figures E-3 and E-4). These walls 

are braced by plywood or equivalent material, or by 

diagonals made of wood or steel. Many detached single family and low-rise multiple family residences in 

the United States are of stud wall wood frame construction.

Post and beam construction, which consists of 

larger rectangular (6 inch by 6 inch and larger) or 

sometimes round wood columns framed together 

with large wood beams or trusses, is not common and 

is found mostly in older buildings. These buildings 

usually are not residential, but are larger buildings 

such as warehouses, churches and theaters.

Timber pole buildings (Figures E-5 and E-6) are 

a less common form of construction found mostly in 

suburban and rural areas. Generally adequate seismically when first built, they are more often subject to 

wood deterioration due to the exposure of the columns, particularly near the ground surface. Together 

with an often-found “soft story” in this building type, 

this deterioration may contribute to unsatisfactory 

seismic performance.

In the western United States, it can be assumed 

that all single detached residential houses (i.e., 

houses with rear and sides separate from adjacent 

structures) are wood stud frame structures unless 

visual or supplemental information indicates otherwise (in the Southwestern U.S., for example, some 

residential homes are constructed of adobe, rammed 

earth, and other non-wood materials). Many houses 

that appear to have brick exterior facades are actually 

wood frame with nonstructural brick veneer or brickpatterned synthetic siding.

In the central and eastern United States, brick 

walls are usually not veneer. For these houses the 

Figure E-1 Single family residence (an example of 

the W1 identifier, light wood-frame 

residential and commercial buildings less 

than 5000 square feet).

Figure E-2 Larger wood-framed structure, typically 

with room-width spans (W2, light, woodframe buildings greater than 5000 square 

feet).
100 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

brick-work must be examined closely to verify that it 

is real brick. Second, the thickness of the exterior 

wall is estimated by looking at a window or door 

opening. If the wall is more than 9 inches from the 

interior finish to exterior surface, then it may be a 

brick wall. Third, if header bricks exist in the brick 

pattern, then it may be a brick wall. If these features 

all point to a brick wall, the house can be assumed to 

be a masonry building, and not a wood frame.

In wetter, humid climates it is common to find 

homes raised four feet or more above the outside 

grade with this space totally exposed (no foundation 

walls). This allows air flow under the house, to minimize decay and rot problems associated with high 

humidity and enclosed spaces. These houses are supported on wood post and small precast concrete pads 

or piers. A common name for this construction is 

post and pier construction.

E.2.2 Typical Earthquake Damage

Stud wall buildings have performed well in past 

earthquakes due to inherent qualities of the structural 

system and because they are lightweight and lowrise. Cracks in any plaster or stucco may appear, but 

these seldom degrade the strength of the building and 

are classified as nonstructural damage. In fact, this 

Figure E-3 Drawing of wood stud frame construction.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 101

type of damage helps dissipate the earthquakeinduced energy of the shaking house. The most common type of structural damage in older buildings 

results from a lack of adequate connection between 

the house and the foundation. Houses can slide off 

their foundations if they are not properly bolted to 

the foundations. This movement (see Figure E-7) 

results in major damage to the building as well as to 

plumbing and electrical connections. Overturning of 

the entire structure is usually not a problem because 

of the low-rise geometry. In many municipalities, 

modern codes require wood structures to be adequately bolted to their foundations. However, the 

year that this practice was adopted will differ from 

community to community and should be checked.

Many of the older wood stud frame buildings 

have no foundations or have weak foundations of 

unreinforced masonry or poorly reinforced concrete. 

These foundations have poor shear resistance to horizontal seismic forces and can fail.

Another problem in older buildings is the stability of cripple walls. Cripple walls are short stud walls 

between the foundation and the first floor level. 

Often these have no bracing neither in-plane nor outof-plane and thus may collapse when subjected to 

horizontal earthquake loading. If the cripple walls 

collapse, the house will sustain considerable damage 

and may collapse. In some older homes, plywood 

sheathing nailed to the cripple studs may have been 

used to rehabilitate the cripple walls. However, if the 

sheathing is not nailed adequately to the studs and 

Figure E-4 Stud wall, wood-framed house.

Figure E-5 Drawing of timber pole framed house.

Figure E-6 Timber pole framed house.

Figure E-7 House off its foundation, 1983 Coalinga 

earthquake.
102 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

foundation sill plate, the cripple walls will still collapse (see Figure E-8).

Homes with post and pier perimeter foundations, 

which are constructed to provide adequate air flow 

under the structure to minimize the potential for 

decay, have little resistance to earthquake forces. 

When these buildings are subjected to strong earthquake ground motions, the posts may rotate or slip of 

the piers and the home will settle to the ground. As 

with collapsed cripple walls, this can be very expensive damage to repair and will result in the home 

building “red-tagged” per the ATC-20 post-earthquake safety evaluation procedures (ATC, 1989, 

1995). See Figure E-9.

Garages often have a large door opening in the 

front wall with little or no bracing in the remainder of 

the wall. This wall has almost no resistance to lateral 

forces, which is a problem if a heavy load such as a 

second story is built on top of the garage. Homes 

built over garages have sustained damage in past 

earthquakes, with many collapses. Therefore the 

house-over-garage configuration, which is found 

commonly in low-rise apartment complexes and 

some newer suburban detached dwellings, should be 

examined more carefully and perhaps rehabilitated.

Unreinforced masonry chimneys present a lifesafety problem. They are often inadequately tied to 

the house, and therefore fall when strongly shaken. 

On the other hand, chimneys of reinforced masonry 

generally perform well.

Some wood-frame structures, especially older 

buildings in the eastern United States, have masonry 

veneers that may represent another hazard. The 

veneer usually consists of one wythe of brick (a 

wythe is a term denoting the width of one brick) 

attached to the stud wall. In older buildings, the 

veneer is either insufficiently attached or has poor 

quality mortar, which often results in peeling of the 

veneer during moderate and large earthquakes.

Post and beam buildings (not buildings with post 

and pier foundations) tend to perform well in earthquakes, if adequately braced. However, walls often 

do not have sufficient bracing to resist horizontal 

motion and thus they may deform excessively.

E.2.3 Common Rehabilitation Techniques

In recent years, especially as a result of the 

Northridge earthquake, emphasis has been placed on 

addressing the common problems associated with 

light-wood framing. This work has concentrated 

mainly in the western United States with single-family residences.

The rehabilitation techniques focus on houses 

with continuous perimeter foundations and cripple 

walls. The rehabilitation work consists of bolting the 

house to the foundation and providing plywood or 

other wood sheathing materials to the cripple walls to 

strengthen them (see Figure E-10). This is the most 

cost-effective rehabilitation work that can be done on 

a single-family residence.

Little work has been done in rehabilitating timber pole buildings or post and pier construction. In 

timber pole buildings rehabilitation techniques are 

focused on providing resistance to lateral forces by 

bracing (applying sheathing) to interior walls, creating a continuous load path to the ground. For homes 

with post and pier perimeter foundations, the work 

has focused on providing partial foundations and 

bracing to carry the earthquake loads. 

Figure E-8 Failed cripple stud wall, 1992 Big Bear 

earthquake.

Figure E-9 Failure of post and pier foundation, 

Humboldt County.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 103

E.3 Steel Frames (S1, S2)

E.3.1 Characteristics

Steel frame buildings generally may be classified as 

either moment-resisting frames or braced frames, 

based on their lateral-force-resisting systems. 

Moment-resisting frames resist lateral loads and 

deformations by the bending stiffness of the beams 

and columns (there is no diagonal bracing). In concentric braced frames the diagonal braces are connected, at each end, to the joints where beams and 

columns meet. The lateral forces or loads are resisted 

by the tensile and compressive strength of the bracing. In eccentric braced frames, the bracing is 

slightly offset from the main beam-to-column connections, and the short section of beam is expected to 

deform significantly in bending under major seismic 

forces, thereby dissipating a considerable portion of 

the energy of the vibrating building. Each type of 

steel frame is discussed below.

Moment-Resisting Steel Frame

Typical steel moment-resisting frame structures usually have similar bay widths in both the transverse 

and longitudinal direction, around 20-30 ft 

(Figure E-11). The load-bearing frame consists of 

beams and columns distributed throughout the building. The floor diaphragms are usually concrete, 

Figure E-10 Seismic strengthening of a cripple wall, 

with plywood sheathing.

Figure E-11 Drawing of steel moment-resisting frame building.
104 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

sometimes over steel decking. Moment-resisting 

frame structures built since 1950 often incorporate 

prefabricated panels hung onto the structural frame 

as the exterior finish. These panels may be precast 

concrete, stone or masonry veneer, metal, glass or 

plastic. 

This structural type is used for commercial, institutional and other public buildings. It is seldom used 

for low-rise residential buildings.

Steel frame structures built before 1945 are usually clad or infilled with unreinforced masonry such 

as bricks, hollow clay tiles and terra cotta tiles and 

therefore should be classified as S5 structures (see 

Section E.6 for a detailed discussion). Other frame 

buildings of this period are encased in concrete. 

Wood or concrete floor diaphragms are common for 

these older buildings.

Braced Steel Frame 

Braced steel frame structures (Figures E-12 and 

E-13) have been built since the late 1800s with similar usage and exterior finish as the steel momentframe buildings. Braced frames are sometimes used 

for long and narrow buildings because of their stiffness. Although these buildings are braced with diagonal members, the bracing members usually cannot 

be detected from the building exterior. 

From the building exterior, it is usually difficult 

to tell the difference between steel moment frames, 

braced frames, and frames with shear walls. In most 

modern buildings, the bracing or shear walls are 

located in the interior or covered by cladding material. Figure E-14 shows heavy diagonal bracing for a 

high rise building, located at the side walls, which 

will be subsequently covered by finish materials and 

will not be apparent. In fact, it is difficult to differentiate steel frame structures and concrete frame structures from the exterior. Most of the time, the 

structural members are clad in finish material. In 

older buildings, steel members can also be encased in 

concrete. There are no positive ways of distinguishing these various frame types except in the two cases 

listed below:

1. If a building can be determined to be a braced 

frame, it is probably a steel structure.

Figure E-12 Braced frame configurations.

Figure E-13 Braced steel frame, with chevron and 

diagonal braces. The braces and steel 

frames are usually covered by finish 

material after the steel is erected.

Figure E-14 Chevron bracing in steel building under 

construction. 
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 105

2. If exposed steel beams and columns can be seen, 

then the steel frame structure is apparent. (Especially in older structures, a structural frame 

which appears to be concrete may actually be a 

steel frame encased in concrete.)

E.3.2 Typical Earthquake Damage

Steel frame buildings tend to be generally satisfactory in their earthquake resistance, because of their 

strength, flexibility and lightness. Collapse in earthquakes has been very rare, although steel frame 

buildings did collapse, for example, in the 1985 Mexico City earthquake. In the United States, these buildings have performed well, and probably will not 

collapse unless subjected to sufficiently severe 

ground shaking. The 1994 Northridge and 1995 

Kobe earthquakes showed that steel frame buildings 

(in particular S1 moment-frame) were vulnerable to 

severe earthquake damage. Though none of the damaged buildings collapsed, they were rendered unsafe 

until repaired. The damage took the form of broken 

welded connections between the beams and columns. 

Cracks in the welds began inside the welds where the 

beam flanges were welded to the column flanges. 

These cracks, in some cases, broke the welds or propagated into the column flange, “tearing” the flange. 

The damage was found in those buildings that experienced ground accelerations of approximately 20% of 

gravity (20%g) or greater. Since 1994 Northridge, 

many cities that experienced large earthquakes in the 

recent past have instituted an inspection program to 

determine if any steel frames were damaged. Since 

steel frames are usually covered with a finish material, it is difficult to find damage to the joints. The 

process requires removal of the finishes and removal 

of fireproofing just to see the joint.

Possible damage includes the following.

1. Nonstructural damage resulting from excessive 

deflections in frame structures can occur to elements such as interior partitions, equipment, and 

exterior cladding. Damage to nonstructural elements was the reason for the discovery of damage to moment frames as a result of the 1994 

Northridge earthquake. 

2. Cladding and exterior finish material can fall if 

insufficiently or incorrectly connected.

3. Plastic deformation of structural members can 

cause permanent displacements.

4. Pounding with adjacent structures can occur.

E.3.3 Common Rehabilitation Techniques

As a result of the 1994 Northridge earthquake many 

steel frame buildings, primarily steel moment frames, 

have been rehabilitated to address the problems discovered. The process is essentially to redo the connections, ensuring that cracks do not occur in the 

welds. There is careful inspection of the welding process and the electrodes during construction. Where 

possible, existing full penetration welds of the beams 

to the columns is changed so more fillet welding is 

used. This means that less heat is used in the welding 

process and consequently there is less potential for 

damage. Other methods include reducing welding to 

an absolute minimum by developing bolted connections or ensuring that the connection plates will yield 

(stretch permanently) before the welds will break. 

One other possibility for rehabilitating moment 

frames is to convert them to braced frames. 

The kind of damage discovered was not limited 

to moment frames, although they were the most 

affected. Some braced frames were found to have 

damage to the brace connections, especially at lower 

levels. 

Structural types other than steel frames are sometimes rehabilitated using steel frames, as shown for 

the concrete structure in Figure E-15. Probably the 

most common use of steel frames for rehabilitation is 

in unreinforced masonry bearing-wall buildings 

(URM). Steel frames are typically used at the storefront windows as there is no available horizontal 

resistance provided by the windows in their plane. 

Frames can be used throughout the first floor perimeter when the floor area needs to be open, as in a restaurant. See Figure E-16.

Figure E-15 Rehabilitation of a concrete parking 

structure using exterior X-braced steel 

frames.
106 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

When a building is encountered with this type of 

rehabilitation scheme, the building should be considered a frame type building S1 or S2. 

E.4 Light Metal (S3)

E.4.1 Characteristics

Most light metal buildings existing today were built 

after 1950 (Figure E-17).They are used for agricultural structures, industrial factories, and warehouses. 

They are typically one story in height, sometimes 

without interior columns, and often enclose a large 

floor area. Construction is typically of steel frames 

spanning the short dimension of the building, resisting lateral forces as moment frames. Forces in the 

long direction are usually resisted by diagonal steel 

rod bracing. These buildings are usually clad with 

lightweight metal or asbestos-reinforced concrete 

siding, often corrugated.

To identify this construction type, the screener 

should look for the following characteristics: Figure E-16 Use of a braced frame to rehabilitate an 

unreinforced masonry building.

Figure E-17 Drawing of light metal construction.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 107

1. Light metal buildings are typically characterized 

by industrial corrugated sheet metal or asbestosreinforced cement siding. The term, “metal 

building panels” should not be confused with 

“corrugated sheet metal siding.” The former are 

prefabricated cladding units usually used for 

large office buildings. Corrugated sheet metal 

siding is thin sheet material usually fastened to 

purlins, which in turn span between columns. If 

this sheet cladding is present, the screener should 

examine closely the fasteners used. If the heads 

of sheet metal screws can be seen in horizontal 

rows, the building is most likely a light metal 

structure (Figure E-18).

2. Because the typical structural system consists of 

moment frames in the transverse direction and 

frames braced with diagonal steel rods in the longitudinal direction, light metal buildings often 

have low-pitched roofs without parapets or overhangs (Figure E-19). Most of these buildings are 

prefabricated, so the buildings tend to be rectangular in plan, without many corners. 

3. These buildings generally have only a few windows, as it is difficult to detail a window in the 

sheet metal system.

4. The screener should look for signs of a metal 

building, and should knock on the siding to see if 

it sounds hollow. Door openings should be 

inspected for exposed steel members. If a gap, or 

light, can be seen where the siding meets the 

ground, it is certainly light metal or wood frame. 

For the best indication, an interior inspection will 

confirm the structural skeleton, because most of 

these buildings do not have interior finishes.

E.4.2 Typical Earthquake Damage

Because these building are low-rise, lightweight, and 

constructed of steel members, they usually perform 

relatively well in earthquakes. Collapses do not usually occur. Some typical problems are listed below:

1. Insufficient capacity of tension braces can lead to 

their elongation or failure, and, in turn, building 

damage.

2. Inadequate connection to the foundation can 

allow the building columns to slide.

3. Loss of the cladding can occur.

E.5 Steel Frame with Concrete Shear 

Wall (S4)

E.5.1 Characteristics

The construction of this structural type (Figure E-20) 

is similar to that of the steel moment-resisting frame 

in that a matrix of steel columns and girders is distributed throughout the structure. The joints, however, are not designed for moment resistance, and the 

lateral forces are resisted by concrete shear walls.

It is often difficult to differentiate visually 

between a steel frame with concrete shear walls and 

one without, because interior shear walls will often 

be covered by interior finishes and will look like 

interior nonstructural partitions. For the purposes of 

an RVS, unless the shear wall is identifiable from the 

exterior (i.e., a raw concrete finish was part of the 

architectural aesthetic of the building, and was left 

exposed), this building cannot be identified accurately. Figure E-21shows a structure with such an 

exposed shear wall. Figure E-22 is a close-up of 

shear wall damage. 

Figure E-18 Connection of metal siding to light metal 

frame with rows of screws (encircled).

Figure E-19 Prefabricated metal building (S3, light 

metal building).
108 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

E.5.2 Typical Earthquake Damage

The shear walls can be part of the elevator and service core, or part of the exterior or interior walls. 

This type of structure performs as well in earthquakes as other steel buildings. Some typical types of 

damage, other than nonstructural damage and pounding, are:

1. Shear cracking and distress can occur around 

openings in concrete shear walls.

2. Wall construction joints can be weak planes, 

resulting in wall shear failure at stresses below 

expected capacity.

3. Insufficient chord steel lap lengths can lead to 

wall bending failures.

E.6 Steel Frame with Unreinforced 

Masonry Infill (S5)

E.6.1 Characteristics

This construction type (Figures E-23 and E-24) consists of a steel structural frame and walls “infilled” 

with unreinforced masonry (URM). In older buildings, the floor diaphragms are often wood. Later 

buildings have reinforced concrete floors. Because of 

the masonry infill, the structure tends to be stiff. 

Because the steel frame in an older building is covered by unreinforced masonry for fire protection, it is 

easy to confuse this type of building with URM bearing-wall structures. Further, because the steel columns are relatively thin, they may be hidden in walls. 

An apparently solid masonry wall may enclose a 

series of steel columns and girders. These infill walls 

are usually two or three wythes thick. Therefore, 

header bricks will sometimes be present and thus 

mislead the screener into thinking the building is a 

URM bearing-wall structure, rather than infill. Often 

in these structures the infill and veneer masonry is 

exposed. Otherwise, masonry may be obscured by 

cladding in buildings, especially those that have 

undergone renovation.

When a masonry building is encountered, the 

screener should first attempt to determine if the 

masonry is reinforced, by checking the date of construction, although this is only a rough guide. A 

Figure E-20 Drawing of steel frame with interior 

concrete shear-walls.

Figure E-21 Concrete shear wall on building exterior.

Figure E-22 Close-up of exterior shear wall damage 

during a major earthquake.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 109

clearer indication of a steel frame structure with 

URM infill is when the building exhibits the characteristics of a frame structure of type S1 or S2. One 

can assume all frame buildings clad in brick and constructed prior to about 1940 are of this type.

Older frame buildings may be of several types—

steel frame encased with URM, steel frame encased 

with concrete, and concrete frame. Sometimes older 

buildings have decorative cladding such as terra cotta 

or stone veneer. Veneers may obscure all evidence of 

URM. In that case, the structural type cannot be 

determined. However, if there is evidence that a large 

amount of concrete is used in the building (for example, a rear wall constructed of concrete), then it is 

unlikely that the building has URM infill.

When the screener cannot be sure if the building 

is a frame or has bearing walls, two clues may help—

the thickness of the walls and the height. Because 

infill walls are constructed of two or three wythes of 

bricks, they should be approximately 9 inches thick 

(2 wythes). Furthermore, the thickness of the wall 

will not increase in the lower stories, because the 

structural frame is carrying the load. For buildings 

over six stories tall, URM is infill or veneer, because 

URM bearing-wall structures are seldom this tall 

and, if so, they will have extremely thick walls in the 

lower stories.

E.6.2 Typical Earthquake Damage

In major earthquakes, the infill walls may suffer substantial cracking and deterioration from in-plane or 

out-of-plane deformation, thus reducing the in-plane 

wall stiffness. This in turn puts additional demand on 

the frame. Some of the walls may fail while others 

remain intact, which may result in torsion or soft 

story problems. 

The hazard from falling masonry is significant as 

these buildings can be taller than 20 stories. As 

Figure E-23 Drawing of steel frame with URM infill.
110 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

described below, typical damage results from a variety of factors.

1. Infill walls tend to buckle and fall out-of-plane 

when subjected to strong lateral forces. Because 

infill walls are non-load-bearing, they tend to be 

thin (around 9") and cannot rely on the additional 

shear strength that accompanies vertical compressive loads. 

2. Veneer masonry around columns or beams is 

usually poorly anchored to the structural members and can disengage and fall.

3. Interior infill partitions and other nonstructural 

elements can be severely damaged and collapse.

4. If stories above the first are infilled, but the first 

is not (a soft story), the difference in stiffness 

creates a large demand at the ground floor columns, causing structural damage.

5. When the earthquake forces are sufficiently high, 

the steel frame itself can fail locally. Connections 

between members are usually not designed for 

high lateral loads (except in tall buildings) and 

this can lead to damage of these connections. 

Complete collapse has seldom occurred, but cannot be ruled out.

E.6.3 Common Rehabilitation Techniques

Rehabilitation techniques for this structural type have 

focused on the expected damage. By far the most significant problem, and that which is addressed in most 

rehabilitation schemes, is failure of the infill wall out 

of its plane. This failure presents a significant life 

safety hazard to individuals on the exterior of the 

building, especially those who manage to exit the 

building during the earthquake. To remedy this problem, anchorage connections are developed to tie the 

masonry infill to the floors and roof of the structure.

Another significant problem is the inherent lack 

of shear strength throughout the building. Some of 

the rehabilitation techniques employed include the 

following.

1. Gunite (with pneumatically placed concrete) the 

interior faces of the masonry wall, creating reinforced concrete shear elements.

2. Rehabilitate the steel frames by providing cross 

bracing or by fully strengthening the connections 

to create moment frames. In this latter case, the 

frames are still not sufficient to resist all the lateral forces, and reliance on the infill walls is necessary to provide adequate strength.

For concrete moment frames the rehabilitation techniques have been to provide ductile detailing. This is 

usually done by removing the outside cover of concrete (a couple of inches) exposing the reinforcing 

ties. Additional ties are added with their ends embedded into the core of the column. The exterior concrete is then replaced. This process results in a detail 

that provides a reasonable amount of ductility but not 

as much as there would have been had the ductility 

been provided in the original design.

E.7 Concrete Moment-Resisting Frame 

(C1)

E.7.1 Characteristics

Concrete moment-resisting frame construction consists of concrete beams and columns that resist both 

lateral and vertical loads (see Figure E-25). A fundamental factor in the seismic performance of concrete 

moment-resisting frames is the presence or absence 

of ductile detailing. Hence, several construction subtypes fall under this category: 

a. non-ductile reinforced-concrete frames with 

unreinforced infill walls,

b. non-ductile reinforced-concrete frames with 

reinforced infill walls,

c. non-ductile reinforced-concrete frames, and

Figure E-24 Example of steel frame with URM infill 

walls (S5).
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 111

d. ductile reinforced-concrete frames.

Ductile detailing refers to the presence of special 

steel reinforcing within concrete beams and columns. 

The special reinforcement provides confinement of 

the concrete, permitting good performance in the 

members beyond the elastic capacity, primarily in 

bending. Due to this confinement, disintegration of 

the concrete is delayed, and the concrete retains its 

strength for more cycles of loading (i.e., the ductility 

is increased). See Figure E-26 for a dramatic example of ductility in concrete.

Ductile detailing (Figure E-27) has been practiced in high-seismicity areas since 1967, when ductility requirements were first introduced into the 

Uniform Building Code (the adoption and enforcement of ductility requirements in a given jurisdiction 

Figure E-25 Drawing of concrete moment-resisting frame building.

Figure E-26 Extreme example of ductility in concrete, 

1994 Northridge earthquake.
112 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

may be later, however). Prior to that time, nonductile 

or ordinary concrete moment-resisting frames were 

the norm (and still are, for moderate seismic areas). 

In high-seismicity areas additional tie reinforcing 

was required following the 1971 San Fernando earthquake and appeared in the Uniform Building Code in 

1976. 

In many low-seismicity areas of the United 

States, non-ductile concrete frames of type (a), (b), 

and (c) continue to be built. This group includes large 

multistory commercial, institutional, and residential 

buildings constructed using flat slab frames, waffle 

slab frames, and the standard beam-and-column 

frames. These structures generally are more massive 

than steel-frame buildings, are under-reinforced (i.e., 

have insufficient reinforcing steel embedded in the 

concrete) and display low ductility.

This building type is difficult to differentiate 

from steel moment-resisting frames unless the structural concrete has been left relatively exposed (see 

Figure E-28). Although a steel frame may be encased 

in concrete and appear to be a concrete frame, this is 

seldom the case for modern buildings (post 1940s). 

For the purpose of the RVS procedures, it can be 

assumed that all exposed concrete frames are concrete and not steel frames.

E.7.2 Typical Earthquake Damage

Under high amplitude cyclic loading, lack of confinement will result in rapid disintegration of nonductile concrete members, with ensuing brittle failure 

and possible building collapse (see Figure E-29).

Causes and types of damage include:

1. Excessive tie spacing in columns can lead to a 

lack of concrete confinement and shear failure.

2. Placement of inadequate rebar splices all at the 

same location in a column can lead to column 

failure.

3. Insufficient shear strength in columns can lead to 

shear failure prior to the full development of 

moment hinge capacity.

4. Insufficient shear tie anchorage can prevent the 

column from developing its full shear capacity.

5. Lack of continuous beam reinforcement can 

result in unexpected hinge formation during load 

reversal.

Figure E-27 Example of ductile reinforced concrete 

column, 1994 Northridge earthquake; 

horizontal ties would need to be closer 

for greater demands. Figure E-28 Concrete moment-resisting frame 

building (C1) with exposed concrete, 

deep beams, wide columns (and with 

architectural window framing).
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 113

6. Inadequate reinforcing of beam-column joints or 

the positioning of beam bar splices at columns 

can lead to failures.

7. The relatively low stiffness of the frame can lead 

to substantial nonstructural damage.

8. Pounding damage with adjacent buildings can 

occur.

E.7.3 Common Rehabilitation Techniques

Rehabilitation techniques for reinforced concrete 

frame buildings depend on the extent to which the 

frame meets ductility requirements. The costs associated with the upgrading an existing, conventional 

beam-column framing system to meet the minimum 

standards for ductility are high and this approach is 

usually not cost-effective. The most practical and 

cost-effective solution is to add a system of shear 

walls or braced frames to provide the required seismic resistance (ATC, 1992). 

E.8 Concrete Shear Wall (C2)

E.8.1 Characteristics

This category consists of buildings with a perimeter concrete bearing-wall structural system or frame 

structures with shear walls (Figure E-30). The structure, including the usual concrete floor diaphragms, 

is typically cast in place. Before the 1940s, bearingwall systems were used in schools, churches, and 

industrial buildings. Concrete shear-wall buildings 

constructed since the early 1950s are institutional, 

commercial, and residential buildings, ranging from 

one to more than thirty stories. Frame buildings with 

shear walls tend to be commercial and industrial. A 

common example of the latter type is a warehouse 

with interior frames and perimeter concrete walls. 

Residential buildings of this type are often mid-rise 

towers. The shear walls in these newer buildings can 

be located along the perimeter, as interior partitions, 

or around the service core.

Frame structures with interior shear walls are difficult to identify positively. Where the building is 

clearly a box-like bearing-wall structure it is probably a shear-wall structure. Concrete shear wall buildings are usually cast in place. The screener should 

look for signs of cast-in-place concrete. In concrete 

bearing-wall structures, the wall thickness ranges 

from 6 to 10 inches and is thin in comparison to that 

of masonry bearing-wall structures.

Figure E-29 Locations of failures at beam-to-column joints in nonductile frames, 1994 Northridge earthquake.
114 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

E.8.2 Typical Types of Earthquake Damage

This building type generally performs better than 

concrete frame buildings. The buildings are heavy 

compared with steel frame buildings, but they are 

also stiff due to the presence of the shear walls. Damage commonly observed in taller buildings is caused 

by vertical discontinuities, pounding, and irregular 

configuration. Other damage specific to this building 

type includes the following.

1. During large seismic events, shear cracking and 

distress can occur around openings in concrete 

shear walls and in spandrel beams and link 

beams between shear walls (See Figures E-31 

and E-32.)

2. Shear failure can occur at wall construction 

joints usually at a load level below the expected 

capacity. 

3. Bending failures can result from insufficient vertical chord steel and insufficient lap lengths at 

the ends of the walls.

E.8.3 Common Rehabilitation

Reinforced concrete shear-wall buildings can be 

rehabilitated in a variety of ways. Techniques 

include: (1) reinforcing existing walls in shear by 

applying a layer of shotcrete or poured concrete; (2) 

where feasible, filling existing window or door openings with concrete to add shear strength and eliminate critical bending stresses at the edge of openings; 

and (3) reinforcing narrow overstressed shear panels 

in in-plane bending by adding reinforced boundary 

elements (ATC, 1992).

E.9 Concrete Frame with Unreinforced 

Masonry Infill (C3)

E.9.1 Characteristics

These buildings (Figures E-33 and E-34) have been, 

and continue to be, built in regions where unreinforced masonry (URM) has not been eliminated by 

code. These buildings were generally built before 

1940 in high-seismicity regions and may continue to 

be built in other regions.

The first step in identification is to determine if 

the structure is old enough to contain URM. In contrast to steel frames with URM infill, concrete frames 

with URM infill usually show clear evidence of the 

concrete frames. This is particularly true for industrial buildings and can usually be observed at the side 

or rear of commercial buildings. The concrete colFigure E-30 Drawing of concrete shear-wall building.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 115

umns and beams are relatively large and are usually 

not covered by masonry but left exposed.

A case in which URM infill cannot be readily 

identified is the commercial building with large windows on all sides; these buildings may have interior 

URM partitions. Another difficult case occurs when 

the exterior walls are covered by decorative tile or 

Figure E-31 Tall concrete shear-wall building: walls 

connected by damaged spandrel beams.

Figure E-32 Shear-wall damage, 1989 Loma Prieta 

earthquake.

Figure E-33 Concrete frame with URM infill.

Figure E-34 Blow-up (lower photo) of distant view of 

C3 building (upper photo) showing 

concrete frame with URM infill (left wall), 

and face brick (right wall).
116 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

stone veneer. The infill material can be URM or a 

thin concrete infill.

E.9.2 Typical Earthquake Damage

The hazards of these buildings, which in the western 

United States are often older, are similar to and perhaps more severe than those of the newer concrete 

frames. Where URM infill is present, a falling hazard 

exists. The failure mechanisms of URM infill in a 

concrete frame are generally the same as URM infill 

in a steel frame.

E.9.3 Common Rehabilitation Techniques

Rehabilitation of unreinforced masonry infill in a 

concrete frame is identical to that of the URM infill 

in a steel frame. See Section E.6.3. Anchorage of the 

wall panels for out-of-plane forces is the key component, followed by providing sufficient shear strength 

in the building. 

E.10 Tilt-up Structures (PC1)

E.10.1 Characteristics

In traditional tilt-up buildings (Figures E-35 through 

E-37), concrete wall panels are cast on the ground 

Figure E-35 Drawing of tilt-up construction typical of the western United States. Tilt-up construction in the eastern 

United States may incorporate a steel frame.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 117

and then tilted upward into their final positions. More 

recently, wall panels are fabricated off-site and 

trucked to the site. 

Tilt-up buildings are an inexpensive form of light 

industrial and commercial construction and have 

become increasingly popular in the western and central United States since the 1940s. They are typically 

one and sometimes two stories high and basically 

have a simple rectangular plan. The walls are the lateral-force-resisting system. The roof can be a plywood diaphragm carried on wood purlins and gluelaminated (glulam) wood beams or a light steel deck 

and joist system, supported in the interior of the 

building on steel pipe columns. The wall panels are 

attached to concrete cast-in-place pilasters or to steel 

columns, or the joint is simply closed with a later 

concrete pour. These joints are typically spaced about 

20 feet apart.

The major defect in existing tilt-ups is a lack of 

positive anchorage between wall and diaphragm, 

which has been corrected since about 1973 in the 

western United States.

In the western United States, it can be assumed 

that all one-story concrete industrial warehouses with 

flat roofs built after 1950 are tilt-ups unless supplementary information indicates otherwise.

E.10.2 Typical Earthquake Damage

Before 1973 in the western United States, many tiltup buildings did not have sufficiently strong connections or anchors between the walls and the roof and 

floor diaphragms. The anchorage typically was nothing more than the nailing of the plywood roof sheathing to the wood ledgers supporting the framing.

During an earthquake, the weak anchorage broke 

the ledgers, resulting in the panels falling and the 

supported framing to collapse. When mechanical 

anchors were used they pulled out of the walls or 

split the wood members to which they were attached, 

causing the floors or roofs to collapse. See 

Figures E-38 and E-39. The connections between the 

concrete panels are also vulnerable to failure. Without these connections, the building loses much of its 

lateral-force-resisting capacity. For these reasons, 

many tilt-up buildings were damaged in the 1971 San 

Figure E-36 Tilt-up industrial building, 1970s.

Figure E-37 Tilt-up industrial building, mid- to late 

1980s.

Figure E-38 Tilt-up construction anchorage failure.

Figure E-39 Result of failure of the roof beam 

anchorage to the wall in tilt-up building.
118 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

Fernando, California, earthquake. Since 1973, tiltup construction practices have changed in California 

and other high-seismicity regions, requiring positive 

wall-diaphragm connection. (Such requirements may 

not have yet been made in other regions of the country.) However, a large number of these older, pre1970s-vintage tilt-up buildings still exist and have 

not been rehabilitated to correct this wall-anchor 

defect. Damage to these buildings was observed 

again in the 1987 Whittier, California, earthquake, 

1989 Loma Prieta, California earthquake, and the 

1994 Northridge, California, earthquake. These 

buildings are a prime source of seismic hazard.

In areas of low or moderate seismicity, inadequate wall anchor details continue to be used. Severe 

ground shaking in such an area may produce major 

damage in tilt-up buildings.

E.10.3 Common Rehabilitation Techniques

The rehabilitation of tilt-up buildings is relatively 

easy and inexpensive. The most common form of 

rehabilitation is to provide a positive anchorage connection at the roof and wall intersection. This is usually done by using pre-fabricated metal hardware 

attached to the framing member and to a bolt that is 

installed through the wall. On the outside of the wall 

a large washer plate is used. See Figure E-40 for 

examples of new anchors.

Accompanying the anchorage rehabilitation is 

the addition of ties across the building to develop the 

anchorage forces from the wall panels fully into the 

diaphragm. This is accomplished by interconnecting 

framing members from one side of the building to the 

other, and then increasing the connections of the diaphragm (usually wood) to develop the additional 

forces.

E.11 Precast Concrete Frame (PC2)

E.11.1 Characteristics

Precast concrete frame construction, first developed 

in the 1930s, was not widely used until the 1960s. 

The precast frame (Figure E-41) is essentially a post 

and beam system in concrete where columns, beams 

and slabs are prefabricated and assembled on site. 

Various types of members are used. Vertical-loadcarrying elements may be Ts, cross shapes, or arches 

and are often more than one story in height. Beams 

are often Ts and double Ts, or rectangular sections. 

Prestressing of the members, including pretensioning 

and post-tensioning, is often employed. The identification of this structure type cannot rely solely on 

construction date, although most precast concrete 

frame structures were constructed after 1960. Some 

typical characteristics are the following.

1. Precast concrete, in general, is of a higher quality 

and precision compared to cast-in-place concrete. It is also available in a greater range of textures and finishes. Many newer concrete and 

steel buildings have precast concrete panels and 

column covers as an exterior finish (See 

Figure E-42). Thus, the presence of precast concrete does not necessarily mean that it is a precast concrete frame.

2. Precast concrete frames are, in essence, post and 

beam construction in concrete. Therefore, when 

a concrete structure displays the features of a 

post-and-beam system, it is most likely that it is a 

precast concrete frame. It is usually not economical for a conventional cast-in-place concrete 

frame to look like a post-and-beam system. Features of a precast concrete post-and-beam system 

include:

a. exposed ends of beams and girders that project 

beyond their supports or project away from the 

building surface,

Figure E-40 Newly installed anchorage of roof beam 

to wall in tilt-up building.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 119

b. the absence of small joists, and

c. beams sitting on top of girders rather than meeting at a monolithic joint (see Figure E-43)

The presence of precast structural components is usually a good indication of this system, although these 

components are also used in mixed construction. Precast structural components come in a variety of 

shapes and sizes. The most common types are sometimes difficult to detect from the street. Less common 

but more obvious examples include the following.

a. Ts or double Ts—These are deep beams with thin 

webs and flanges and with large span capacities. 

(Figure E-44 shows one end of a double-T beam 

as it is lowered onto its seat.)

b. Cross or T-shaped units of partial columns and 

beams — These are structural units for constructing moment-resisting frames. They are usually 

joined together by field welding of steel connectors cast into the concrete. Joints should be 

clearly visible at the mid-span of the beams or 

the mid-height of the columns. See Figure E-45. 

c. Precast arches—Precast arches and pedestals are 

popular in the architecture of these buildings.

d. Column—When a column displays a precast finish without an indication that it has a cover (i.e., 

Figure E-41 Drawing of precast concrete frame building.
120 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

no vertical seam can be found), the column is 

likely to be a precast structural column.

It is possible that a precast concrete frame may not 

show any of the above features, however.

E.11.2 Typical Earthquake Damage

The earthquake performance of this structural type 

varies widely and is sometimes poor. This type of 

building can perform well if the detailing used to 

connect the structural elements have sufficient 

strength and ductility (toughness). Because structures 

of this type often employ cast-in-place concrete or 

reinforced masonry (brick or block) shear walls for 

lateral-load resistance, they experience the same 

types of damage as other shear-wall building types. 

Some of the problem areas specific to precast frames 

are listed below.

1. Poorly designed connections between prefabricated elements can fail.

2. Accumulated stresses can result due to shrinkage 

and creep and due to stresses incurred in transportation.

3. Loss of vertical support can occur due to inadequate bearing area and insufficient connection 

between floor elements and columns.

4. Corrosion of the metal connectors between prefabricated elements can occur.

E.11.3 Common Rehabilitation Techniques

Seismic rehabilitation techniques for precast concrete 

frame buildings are varied, depending on the elements being strengthened. Inadequate shear capacity 

of floor diaphragms can be addressed by adding reinforced concrete topping to an untopped system when 

Figure E-42 Typical precast column cover on a steel 

or concrete moment frame.

Figure E-43 Exposed precast double-T sections and

overlapping beams are indicative of 

precast frames.

Figure E-44 Example of precast double-T section 

during installation.

Figure E-45 Precast structural cross; installation joints 

are at sections where bending is 

minimum during high seismic demand.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 121

possible, or adding new shear walls to reduce the 

seismic shear forces in the diaphragm. Corbels with 

inadequate vertical shear or bending strength can be 

strengthened by adding epoxied horizontal shear 

dowels through the corbel and into the column. 

Alternatively, vertical shear capacity can be 

increased by adding a structural steel bolster under 

the corbel, bolted to the column, or a new steel column or reinforced concrete column can be added 

(ATC, 1992). 

E.12 Reinforced Masonry (RM1 and 

RM2)

E.12.1 Characteristics

Reinforced masonry buildings are mostly low-rise 

structures with perimeter bearing walls, often with 

wood diaphragms (RM1 buildings) although precast 

concrete is sometimes used (RM2 buildings). Floor 

and roof assemblies usually consist of timber joists 

and beams, glued-laminated beams, or light steel 

joists. The bearing walls consist of grouted and reinforced hollow or solid masonry units. Interior supports, if any, are often wood or steel columns, wood 

stud frames, or masonry walls. Occupancy varies 

from small commercial buildings to residential and

industrial buildings. Generally, they are less than five 

stories in height although many taller masonry buildings exist. Reinforced masonry structures are usually 

basically rectangular structures (See Figure E-46).

To identify reinforced masonry, one must determine separately if the building is masonry and if it is 

reinforced. To obtain information on how to recognize a masonry structure, see Appendix D, which 

describes the characteristics of construction materials. The best way of assessing the reinforcement condition is to compare the date of construction with the 

date of code requirement for the reinforcement of 

masonry in the local jurisdiction.

The screener also needs to determine if the building is veneered with masonry or is a masonry building. Wood siding is seldom applied over masonry. If 

the front facade appears to be reinforced masonry 

whereas the side has wood siding, it is probably a 

wood frame that has undergone facade renovation. 

The back of the building should be checked for signs 

of the original construction type.

If it can be determined that the bearing walls are 

constructed of concrete blocks, they may be reinforced. Load-bearing structures using these blocks 

are probably reinforced if the local code required it. 

Concrete blocks come in a variety of sizes and textures. The most common size is 8 inches wide by 16 

inches long by 8 inches high. Their presence is obvious if the concrete blocks are left as the finish surface.

E.12.2 Typical Earthquake Damage

Reinforced masonry buildings can perform well in 

moderate earthquakes if they are adequately reinforced and grouted, and if sufficient diaphragm 

anchorage exists. A major problem is control of the 

workmanship during construction. Poor construction practice can result in ungrouted and unreinforced 

walls. Even where construction practice is adequate, 

insufficient reinforcement in the design can be 

responsible for heavy damage of the walls. The lack 

of positive connection of the floor and roof diaphragms to the wall is also a problem.

E.12.3 Common Rehabilitation Techniques

Techniques for seismic rehabilitation of reinforced 

masonry bearing wall buildings are varied, depending on the element being rehabilitated. Techniques 

for rehabilitating masonry walls include: (1) applying 

a layer of concrete or shotcrete to the existing walls; 

(2) adding vertical reinforcing and grouting into 

ungrouted block walls; and (3) filling in large or critical openings with reinforced concrete or masonry 

dowelled to the surrounding wall. Wood or steel 

deck diaphragms in RM1 buildings can be rehabilitated by adding an additional layer of plywood to 

strengthen and stiffen an existing wood diaphragm, 

by shear welding between sections of an existing 

steel deck or adding flat sheet steel reinforcement, or 

by adding additional vertical elements (for example, 

shear walls or braced frames) to decrease diaphragm 

spans and stresses. Precast floor diaphragms in RM2 

buildings can be strengthen by adding a layer of concrete topping reinforced with mesh (if the supporting 

structure has the capacity to carry the additional vertical dead load), or by adding new shear walls to 

reduce the diaphragm span (ATC, 1992).

Figure E-46 Modern reinforced brick masonry.
122 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

E.13 Unreinforced Masonry (URM)

E.13.1 Characteristics

Most unreinforced masonry (URM) bearing-wall 

structures in the western United States (Figures E-47 

through E-51) were built before 1934, although this 

construction type was permitted in some jurisdictions 

having moderate or high seismicity until the late 

1940s or early 1950s (in some jurisdictions URM 

may still be a common type of construction, even 

today). These buildings usually range from one to six 

stories in height and function as commercial, residential, or industrial buildings. The construction varies 

according to the type of use, although wood floor and 

roof diaphragms are common. Smaller commercial 

and residential buildings usually have light wood 

floor joists and roof joists supported on the typical 

perimeter URM wall and interior, wood, load-bearing partitions. Larger buildings, such as industrial 

warehouses, have heavier floors and interior columns, usually of wood. The bearing walls of these 

industrial buildings tend to be thick, often as much as 

24 inches or more at the base. Wall thickness of residential, commercial, and office buildings range from 

9 inches at upper floors to 18 inches a lower floors.

The first step in identifying buildings of this type 

is to determine if the structure has bearing walls. Second, the screener should determine the approximate 

age of the building. Some indications of unreinforced 

masonry are listed below.

1. Weak mortar was used to bond the masonry units 

together in much of the early unreinforced 

Figure E-47 Drawing of unreinforced masonry bearing-wall building, 2-story.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 123

masonry construction in the United States. As the 

poor earthquake performance of this mortar type 

became known in the 1930s, and as cement mortar became available, this weaker mortar was not 

used and thus is not found in more recent 

masonry buildings. If this soft mortar is present, 

it is probably URM. Soft mortar can be scratched 

with a hard instrument such as a penknife, screwdriver, or a coin. This scratch testing, if permitted, should be done in a wall area where the 

original structural material is exposed, such as 

the sides or back of a building. Newer masonry 

may be used in renovations and it may look very 

much like the old. Older mortar joints can also be 

repointed (i.e., regular maintenance of the 

masonry mortar), or repaired with newer mortar 

during renovation. The original construction may 

also have used a high-quality mortar. Thus, even 

if the existence of soft mortar cannot be detected, 

it may still be URM.

2. An architectural characteristic of older brick 

bearing-wall structures is the arch and flat arch 

Figure E-48 Drawing of unreinforced masonry bearing-wall building, 4-story.
124 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

Figure E-49 Drawing of unreinforced masonry bearing-wall building, 6-story.

Figure E-50 East coast URM bearing-wall building. Figure E-51 West coast URM bearing-wall building.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 125

window heads (see Figure E-52). These arrangements of masonry units function as a header to 

carry the load above the opening to either side. 

Although masonry-veneered wood-frame structures may have these features, they are much 

more widely used in URM bearing-wall structures, as they were the most economical method 

of spanning over a window opening at the time 

of construction. Other methods of spanning are 

also used, including steel and stone lintels, but 

these methods are generally more costly and usually employed in the front facade only.

3. Some structures of this type will have anchor 

plates visible at the floor and roof lines, approximately 6-10 feet on center around the perimeter 

of the building. Anchor plates are usually square 

or diamond-shaped steel plates approximately 6 

inches by 6 inches, with a bolt and nut at the center. Their presence indicates anchor ties have 

been placed to tie the walls to the floors and roof. 

These are either from the original construction or 

from rehabilitation under local ordinances. 

Unless the anchors are 6 feet on center or less, 

they are not considered effective in earthquakes. 

If they are closely spaced, and appear to be 

recently installed, it indicates that the building 

has been rehabilitated. In either case, when these 

anchors are present all around the building, the 

original construction is URM bearing wall.

4. When a building has many exterior solid walls 

constructed from hollow clay tile, and no columns of another material can be detected, it is 

probably not a URM bearing wall but probably a 

wood or metal frame structure with URM infill.

5. One way to distinguish a reinforced masonry 

building from an unreinforced masonry building 

is to examine the brick pattern closely. Reinforced masonry usually does not show header 

bricks in the wall surface.

Figure E-52 Drawings of typical window head features in URM bearing-wall buildings.
126 E: Characteristics and Earthquake Performance of RVS Building Types FEMA 154

If a building does not display the above features, or if 

the exterior is covered by other finish material, the 

building may still be URM.

E.13.2 Typical Earthquake Damage

Unreinforced masonry structures are recognized as 

the most hazardous structural type. They have been 

observed to fail in many modes during past earthquakes. Typical problems include the following.

1. Insufficient Anchorage—Because the walls, parapets, and cornices are not positively anchored to 

the floors, they tend to fall out. The collapse of 

bearing walls can lead to major building collapses. Some of these buildings have anchors as a 

part of the original construction or as a rehabilitation. These older anchors exhibit questionable 

performance. (See Figure E-53 for parapet damage.)

2. Excessive Diaphragm Deflection—Because 

most of the floor diaphragms are constructed of 

finished wood flooring placed over 3⁄4”-thick 

wood sheathing, they tend to be stiff compared 

with other types of wood diaphragms. This stiffness results in rotations about a vertical axis, 

accompanying translations in the direction of the 

open front walls of buildings, due to a lack of inplane stiffness in these open fronts. Because 

there is little resistance in the masonry walls for 

out-of-plane loading, the walls allow large diaphragm displacements and cause the failure of 

the walls out of their plane. Large drifts occurring at the roof line can cause a masonry wall to 

overturn and collapse under its own weight.

3. Low Shear Resistance—The mortar used in these 

older buildings was often made of lime and sand, 

with little or no cement, and had very little shear 

strength. The bearing walls will be heavily damaged and collapse under large loads. (See 

Figure E-54)

4. Slender Walls —Some of these buildings have 

tall story heights and thin walls. This condition, 

especially in non-load-bearing walls, will result 

in buckling out-of-plane under severe lateral 

load. Failure of a non-load-bearing wall represents a falling hazard, whereas the collapse of a 

load-bearing wall will lead to partial or total collapse of the structure.

E.13.3 Common Rehabilitation Techniques

Over the last 10 years or more, jurisdictions in California have required that unreinforced masonry bearing-wall buildings be rehabilitated or demolished. To 

minimize the economical impact on owners of having to rehabilitate their buildings, many jurisdictions 

implemented phased programs such that the critical 

items were dealt with first. The following are the key 

elements included in a typical rehabilitation program.

1. Roof and floor diaphragms are connected to the 

walls for both anchorage forces (out of the plane 

of the wall) and shear forces (in the plane of the 

Figure E-53 Parapet failure leaving an uneven roof 

line, due to inadequate anchorage, 1989 

Loma Prieta earthquake.

Figure E-54 Damaged URM building,

1992 Big Bear earthquake.
FEMA 154 E: Characteristics and Earthquake Performance of RVS Building Types 127

wall). Anchorage connections are placed at 6 feet 

spacing or less, depending on the force requirements. Shear connections are usually placed at 

around 2 feet center to center. Anchors consist of 

bolts installed through the wall, with 6-inchsquare washer plates, and connected to hardware 

attached to the wood framing. Shear connections 

usually are bolts embedded in the masonry walls 

in oversized holes filled with either a non-shrink 

grout or an epoxy adhesive. See Figure E-55.

2. In cases when the height to thickness ratio of the 

walls exceeds the limits of stability, rehabilitation consists of reducing the spans of the wall to 

a level that their thickness can support. Parapet 

rehabilitation consists of reducing the parapet to 

what is required for fire safety and then bracing 

from the top to the roof.

3. If the building has an open storefront in the first 

story, resulting in a soft story, part of the storefront is enclosed with new masonry or a steel 

frame is provided there, with new foundations.

4. Walls are rehabilitated by either closing openings 

with reinforced masonry or with reinforced 

gunite.

Figure E-55 Upper: Two existing anchors above three 

new wall anchors at floor line using 

decorative washer plates. Lower: 

Rehabilitation techniques include closely 

spaced anchors at floor and roof levels.

FEMA 154 F: Earthquakes and How Buildings Resist Them 129

Appendix F

Earthquakes and How Buildings

Resist Them

F.1 The Nature of Earthquakes

In a global sense, earthquakes result from motion 

between plates comprising the earth’s crust (see 

Figure F-1). These plates are driven by the convective motion of the material in the earth’s mantle 

between the core and the crust, which in turn is 

driven by heat generated at the earth’s core. Just as in 

a heated pot of water, heat from the earth’s core 

causes material to rise to the earth’s surface. Forces 

between the rising material and the earth’s crustal 

plates cause the plates to move. The resulting relative 

motions of the plates are associated with the generation of earthquakes. Where the plates spread apart, 

molten material fills the void. An example is the 

ridge on the ocean floor, at the middle of the Atlantic 

Ocean. This material quickly cools and, over millions 

of years, is driven by newer, viscous, fluid material 

across the ocean floor.

These large pieces of the earth’s surface, termed 

tectonic plates, move very slowly and irregularly. 

Forces build up for decades, centuries, or millennia at 

the interfaces (or faults) between plates, until a large 

releasing movement suddenly occurs. This sudden, 

violent motion produces the nearby shaking that is 

felt as an earthquake. Strong shaking produces strong 

horizontal forces on structures, which can cause 

direct damage to buildings, bridges, and other manmade structures as well as triggering fires, landslides, 

road damage, tidal waves (tsunamis) and other damaging phenomena.

Figure F-1 The separate tectonic plates comprising the earth’s crust superimposed on a map of the world.
130 F: Earthquakes and How Buildings Resist Them FEMA 154

A fault is like a “tear” in the earth’s crust and its 

fault surface may be from one to over one hundred 

miles deep. In some cases, faults are the physical 

expression of the boundary between adjacent tectonic 

plates and thus are hundreds of miles long. In addition, there are shorter faults, parallel to, or branching 

out from, a main fault zone. Generally, the longer a 

fault, the larger magnitude earthquake it can generate. Beyond the main tectonic plates, there are many 

smaller sub-plates, “platelets” and simple blocks of 

crust which can move or shift due to the “jostling” of 

their neighbors and the major plates. The known 

existence of these many sub-plates implies that 

smaller but still damaging earthquakes are possible 

almost anywhere.

With the present understanding of the earthquake 

generating mechanism, the times, sizes and locations 

of earthquakes cannot be reliably predicted. Generally, earthquakes will be concentrated in the vicinity 

of faults, and certain faults are more likely than others to produce a large event, but the earthquake generating process is not understood well enough to 

predict the exact time of earthquake occurrence. 

Therefore, communities must be prepared for an 

earthquake to occur at any time.

Four major factors can affect the severity of 

ground shaking and thus potential damage at a site. 

These are the magnitude of the earthquake, the type 

of earthquake, the distance from the source of the 

earthquake to the site, and the hardness or softness of 

the rock or soil at the site. Larger earthquakes will 

shake longer and harder, and thus cause more damage. Experience has shown that the ground motion 

can be felt for several seconds to a minute or longer. 

In preparing for earthquakes, both horizontal (side to 

side) and vertical shaking must be considered.

There are many ways to describe the size and 

severity of an earthquake and associated ground 

shaking. Perhaps the most familiar are earthquake 

magnitude and Modified Mercalli Intensity (MMI, 

often simply termed “intensity”). Earthquake magnitude is technically known as the Richter magnitude, a 

numerical description of the maximum amplitude of 

ground movement measured by a seismograph 

(adjusted to a standard setting). On the Richter scale, 

the largest recorded earthquakes have had magnitudes of about 8.5. It is a logarithmic scale, and a unit 

increase in magnitude corresponds to a ten-fold 

increase in the adjusted ground displacement amplitude, and to approximately a thirty-fold increase in 

total potential strain energy released by the earthquake.

Modified Mercalli Intensity (MMI) is a subjective scale defining the level of shaking at specific 

sites on a scale of I to XII. (MMI is expressed in 

Roman numerals, to connote its approximate nature.) 

For example, slight shaking that causes few instances 

of fallen plaster or cracks in chimneys constitutes 

MMI VI. It is difficult to find a reliable precise relationship between magnitude, which is a description 

of the earthquake’s total energy level, and intensity, 

which is a subjective description of the level of shaking of the earthquake at specific sites, because shaking intensity can vary with earthquake magnitude, 

soil type, and distance from the event.

The following analogy may be worth remembering: earthquake magnitude and intensity are similar 

to a light bulb and the light it emits. A particular light 

bulb has only one energy level, or wattage (e.g., 100 

watts, analogous to an earthquake’s magnitude). Near 

the light bulb, the light intensity is very bright (perhaps 100 foot-candles, analogous to MMI IX), while 

farther away the intensity decreases (e.g., 10 footcandles, MMI V). A particular earthquake has only 

one magnitude value, whereas it has intensity values 

that differ throughout the surrounding land.

MMI is a subjective measure of seismic intensity 

at a site, and cannot be measured using a scientific 

instrument. Rather, MMI is estimated by scientists 

and engineers based on observations, such as the 

degree of disturbance to the ground, the degree of 

damage to typical buildings and the behavior of people. A more objective measure of seismic shaking at 

a site, which can be measured by instruments, is a 

simple structure’s acceleration in response to the 

ground motion. In this Handbook, the level of ground 

shaking is described by the spectral response acceleration.

F.2 Seismicity of the United States

Maps showing the locations of earthquake epicenters 

over a specified time period are often used to characterize the seismicity of given regions. Figures F-2, 

F-3, and F-4 show the locations of earthquake epicenters4

 in the conterminous United States, Alaska, 

and Hawaii, respectively, recorded during the time 

period, 1977-1997. It is evident from Figures F-2 

through F-4 that some parts of the country have experienced more earthquakes than others. The boundary 

between the North American and Pacific tectonic 

plates lies along the west coast of the United States 

and south of Alaska. The San Andreas fault in California and the Aleutian Trench off the coast of 

Alaska are part of this boundary. These active seismic zones have generated earthquakes with Richter 

4An epicenter is defined as the point on the earth’s 

surface beneath which the rupture process for a 

given earthquake commenced.
FEMA 154 F: Earthquakes and How Buildings Resist Them 131

magnitudes greater than 8. There are many other 

smaller fault zones throughout the western United 

States that are also participating intermittently in 

releasing the stresses and strains that are built up as 

the tectonic plates try to move past one another. 

Because earthquakes always occur along faults, the 

seismic hazard will be greater for those population 

centers close to active fault zones.

In California the earthquake hazard is so significant that special study zones have been created by the 

legislature, and named Alquist-Priola Special Study 

Zones. These zones cover the larger known faults 

and require special geotechnical studies to be performed in order to establish design parameters.

On the east coast of the United States, the 

sources of earthquakes are less understood. There is 

no plate boundary and few locations of faults are 

known. Therefore, it is difficult to make statements 

about where earthquakes are most likely to occur. 

Several significant historical earthquakes have 

occurred, such as in Charleston, South Carolina, in 

1886 and New Madrid, Missouri, in 1811 and 1812, 

indicating that there is potential for large earthquakes. However, most earthquakes in the eastern 

United States are smaller magnitude events. Because 

of regional geologic differences, specifically, the 

hardness of the crustal rock, eastern and central U.S. 

earthquakes are felt at much greater distances from 

their sources than those in the western United States, 

sometimes at distances up to a thousand miles.

F.3 Earthquake Effects

Many different types of damage can occur in buildings. Damage can be divided into two categories: 

structural and nonstructural, both of which can be 

hazardous to building occupants. Structural damage 

means degradation of the building’s structural support systems (i.e., vertical- and lateral-force-resisting 

systems), such as the building frames and walls. 

Nonstructural damage refers to any damage that does 

not affect the integrity of the structural support systems. Examples of nonstructural damage are chimneys collapsing, windows breaking, or ceilings 

falling. The type of damage to be expected is a complex issue that depends on the structural type and age 

of the building, its configuration, construction materials, the site conditions, the proximity of the building to neighboring buildings, and the type of nonstructural elements.

Figure F-2 Seismicity of the conterminous United States 1977 − 1997 (from the website at http://neic.usgs.gov/

neis/general/seismicity/us.html). This reproduction shows earthquake locations without regard to 

magnitude or depth. The San Andreas fault and other plate boundaries are indicated with white lines.
132 F: Earthquakes and How Buildings Resist Them FEMA 154

Figure F-3 Seismicity of Alaska 1977 − 1997. The white line close to most of the earthquakes is the plate 

boundary, on the ocean floor, between the Pacific and North America plates.

Figure F-4 Seismicity of Hawaii 1977 − 1997. See Figure F-2 caption.
FEMA 154 F: Earthquakes and How Buildings Resist Them 133

When strong earthquake shaking occurs, a building is thrown mostly from side to side, and also up 

and down. That is, while the ground is violently 

moving from side to side, taking the building foundation with it, the building structure tends to stay at 

rest, similar to a passenger standing on a bus that 

accelerates quickly. Once the building starts moving, 

it tends to continue in the same direction, but the 

ground moves back in the opposite direction (as if 

the bus driver first accelerated quickly, then suddenly 

braked). Thus the building gets thrown back and 

forth by the motion of the ground, with some parts of 

the building lagging behind the foundation movement, and then moving in the opposite direction. The 

force F that an upper floor level or roof level of the 

building should successfully resist is related to its 

mass m and its acceleration a, according to Newton’s 

law, F = ma. The heavier the building the more the 

force is exerted. Therefore, a tall, heavy, reinforcedconcrete building will be subject to more force than a 

lightweight, one-story, wood-frame house, given the 

same acceleration.

Damage can be due either to structural members 

(beams and columns) being overloaded or differential movements between different parts of the structure. If the structure is sufficiently strong to resist 

these forces or differential movements, little damage 

will result. If the structure cannot resist these forces 

or differential movements, structural members will 

be damaged, and collapse may occur.

Building damage is related to the duration and 

the severity of the ground shaking. Larger earthquakes tend to shake longer and harder and therefore 

cause more damage to structures. Earthquakes with 

Richter magnitudes less than 5 rarely cause significant damage to buildings, since acceleration levels 

(except when the site is on the fault) and duration of 

shaking for these earthquakes are relatively small.

In addition to damage caused by ground shaking, 

damage can be caused by buildings pounding against 

one another, ground failure that causes the degradation of the building foundation, landslides, fires and 

tidal waves (tsunamis). Most of these “indirect” 

forms of damage are not addressed in this Handbook.

Generally, the farther from the source of an 

earthquake, the less severe the motion. The rate at 

which motion decreases with distance is a function of 

the regional geology, inherent characteristics and 

details of the earthquake, and its source location. The 

underlying geology of the site can also have a significant effect on the amplitude of the ground motion 

there. Soft, loose soils tend to amplify the ground 

motion and in many cases a resonance effect can 

make it last longer. In such circumstances, building 

damage can be accentuated. In the San Francisco 

earthquake of 1906, damage was greater in the areas 

where buildings were constructed on loose, manmade fill and less at the tops of the rocky hills. Even 

more dramatic was the 1985 Mexico City earthquake. This earthquake occurred 250 miles from the 

city, but very soft soils beneath the city amplified the 

ground shaking enough to cause weak mid-rise buildings to collapse (see Figure F-5). Resonance of the 

building frequency with the amplified ground shaking frequency played a significant role. Sites with 

rock close to or at the surface will be less likely to 

amplify motion. The type of motion felt also changes 

with distance from the earthquake. Close to the 

source the motion tends to be violent rapid shaking, 

whereas farther away the motion is normally more of 

a swaying nature. Buildings will respond differently 

to the rapid shaking than to the swaying motion. 

Each building has its own vibrational characteristics that depend on building height and structural 

type. Similarly, each earthquake has its own vibrational characteristics that depend on the geology of 

the site, distance from the source, and the type and 

site of the earthquake source mechanism. Sometimes 

a natural resonant frequency of the building and a 

prominent frequency of the earthquake motion are 

similar and cause a sympathetic response, termed 

resonance. This causes an increase in the amplitude 

of the building’s vibration and consequently 

increases the potential for damage. 

Resonance was a major problem in the 1985 

Mexico City earthquake, in which the total collapse 

of many mid-rise buildings (Figure F-5) caused 

many fatalities. Tall buildings at large distances from 

the earthquake source have a small, but finite, probability of being subjected to ground motions containing frequencies that can cause resonance.

Where taller, more flexible, buildings are susceptible to distant earthquakes (swaying motion) shorter 

Figure F-5 Mid-rise building collapse, 1985 Mexico 

City earthquake.
134 F: Earthquakes and How Buildings Resist Them FEMA 154

and stiffer buildings are more susceptible to nearby 

earthquakes (rapid shaking). Figure F-6 shows the 

effects on shorter, stiffer structures that are close to 

the source. The inset picture shows the interior of the 

house. Accompanying the near field effects is surface 

faulting also shown in Figure F-6.

The level of damage that results from a major 

earthquake depends on how well a building has been 

designed and constructed. The exact type of damage 

cannot be predicted because no two buildings 

undergo identical motion. However, there are some 

general trends that have been observed in many 

earthquakes.

● Newer buildings generally sustain less damage 

than older buildings designed to earlier codes. 

● Common problems in wood-frame construction 

are the collapse of unreinforced chimneys 

(Figure F-7) houses sliding off their foundations 

(Figure F-8),collapse of cripple walls 

(Figure F-9), or collapse of post and pier foundations (Figure F-10). Although such damage may 

be costly to repair, it is not usually life threatening.

● The collapse of load bearing walls that support 

an entire structure is a common form of damage 

in unreinforced masonry structures 

(Figure F-11). 

● Similar types of damage have occurred in many 

older tilt-up buildings (Figure F-12). 

From a life-safety perspective, vulnerable buildings need to be clearly identified, and then strengthened or demolished.

F.4 How Buildings Resist Earthquakes

As described above, buildings experience horizontal 

distortion when subjected to earthquake motion. 

When these distortions get large, the damage can be 

catastrophic. Therefore, most buildings are designed 

Figure F-6 Near-field effects, 1992 Landers earthquake, showing house (white arrow) close to surface faulting 

(black arrow); the insert shows a house interior.

Figure F-7 Collapsed chimney with damaged roof, 

1987 Whittier Narrows earthquake.
FEMA 154 F: Earthquakes and How Buildings Resist Them 135

with lateral-force-resisting systems (or seismic systems), to resist the effects of earthquake forces. In 

many cases seismic systems make a building stiffer 

against horizontal forces, and thus minimize the 

amount of relative lateral movement and consequently the damage. Seismic systems are usually 

designed to resist only forces that result from horizontal ground motion, as distinct from vertical 

ground motion.

The combined action of seismic systems along 

the width and length of a building can typically resist 

earthquake motion from any direction. Seismic systems differ from building to building because the 

type of system is controlled to some extent by the 

basic layout and structural elements of the building. 

Basically, seismic systems consist of axial-, shearand bending-resistant elements.

In wood-frame, stud-wall buildings, plywood 

siding is typically used to prevent excessive lateral 

deflection in the plane of the wall. Without the extra 

strength provided by the plywood, walls would distort excessively or “rack,” resulting in broken windows and stuck doors. In older wood frame houses, 

Figure F-8 House that slid off foundation, 

1994 Northridge earthquake.

Figure F-9 Collapsed cripple stud walls dropped 

this house to the ground, 1992 Landers 

and Big Bear earthquakes.

Figure F-10 This house has settled to the ground due 

to collapse of its post and pier 

foundation.

Figure F-11 Collapse of unreinforced masonry 

bearing wall, 1933 Long Beach 

earthquake.

Figure F-12 Collapse of a tilt-up bearing wall.
136 F: Earthquakes and How Buildings Resist Them FEMA 154

this resistance to lateral loads is provided by either 

wood or steel diagonal bracing.

The earthquake-resisting systems in modern steel 

buildings take many forms. In moment-resisting steel 

frames, the connections between the beams and the 

columns are designed to resist the rotation of the column relative to the beam. Thus, the beam and the 

column work together and resist lateral movement 

and lateral displacement by bending. Steel frames 

sometimes include diagonal bracing configurations, 

such as single diagonal braces, cross-bracing and “Kbracing.” In braced frames, horizontal loads are 

resisted through tension and compression forces in 

the braces with resulting changed forces in the beams 

and columns. Steel buildings are sometimes constructed with moment-resistant frames in one direction and braced frames in the other.

In concrete structures, shear walls are sometimes 

used to provide lateral resistance in the plane of the 

wall, in addition to moment-resisting frames. Ideally, 

these shear walls are continuous reinforced-concrete 

walls extending from the foundation to the roof of 

the building. They can be exterior walls or interior 

walls. They are interconnected with the rest of the 

concrete frame, and thus resist the horizontal motion 

of one floor relative to another. Shear walls can also 

be constructed of reinforced masonry, using bricks or 

concrete blocks.
FEMA-154 References 137 

References 

ASCE, 1998, Handbook for the Seismic 

Evaluation of Buildings — A Pre-standard, 

prepared by the American Society of Civil 

Engineers for the Federal Emergency 

Management Agency, FEMA 310 Report, 

Washington D.C. 

ASCE, 2000, Prestandard and Commentary for 

the Seismic Rehabilitation of Buildings, 

prepared by the American Society of Civil 

Engineers for the Federal Emergency 

Management Agency, FEMA 356 Report, 

Washington, D.C. 

ATC, 1987, Evaluating the Seismic Resistance of 

Existing Buildings, Applied Technology 

Council, ATC-14 Report, Redwood City, 

California. 

ATC, 1989, Procedures for Postearthquake Safety 

Evaluation of Buildings, Applied Technology 

Council, ATC-20 Report, Redwood City, 

California. 

ATC, 1992, Procedures for Building Seismic 

Rehabilitation (Interim), Applied Technology 

Council, ATC-26-4 Report, Redwood City, 

California 

ATC, 1995, Addendum to the ATC-20 

Postearthquake Building Safety Procedures

Applied Technology Council, ATC-20-2 

Report, Redwood City, California. 

ATC, 1988a, Rapid Visual Screening of Buildings 

for Potential Seismic Hazards: A Handbook, 

prepared by the Applied Technology Council 

for the Federal Emergency Management 

Agency, FEMA 154 Report, Washington, 

D.C. 

ATC, 1988b, Rapid Visual Screening of Buildings 

for Potential Seismic Hazards: Supporting 

Documentation, prepared by the Applied 

Technology Council for the Federal 

Emergency Management Agency, FEMA 155 

Report, Washington, D.C. 

ATC, 1997a, 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, 

FEMA 273 Report, Washington, D.C. 

ATC, 1997b, 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, FEMA 274 

Report, Washington, D.C. 

ATC, 2002, Rapid Visual Screening of Buildings 

for Potential Seismic Hazards: Supporting 

Documentation (2nd edition), prepared by the 

Applied Technology Council for the Federal 

Emergency Management Agency, FEMA 155 

Report, Washington, D.C. 

BSSC, 1992, NEHRP Handbook for the Seismic 

Evaluation of Existing Buildings, prepared by 

the Building Seismic Safety Council for the 

Federal Emergency Management Agency, 

FEMA 178 Report, Washington D.C. 

BSSC, 1997, NEHRP Recommended Provisions 

for the Seismic Regulations for New Buildings 

and Other Structures, and Commentary, 

prepared by the Building Seismic Safety 

Council for the Federal Emergency 

Management Agency, FEMA 302 and 303 

Reports, Washington, D.C. 

BSSC, 2000, NEHRP Recommended Provisions 

for the Seismic Regulations for New Buildings 

and Other Structures, and Commentary, 2000 

Edition, prepared by the Building Seismic 

Safety Council for the Federal Emergency 

Management Agency, FEMA 368 and 369 

Reports, Washington, D.C. 

EERI, 1998, Seismic Rehabilitation of Buildings: 

Strategic Plan 2005, prepared by the 

Earthquake Engineering Research Institute for 

the Federal Emergency Management Agency, 

FEMA 315 Report, Washington, D.C. 

FEMA, 1995, Typical Costs for Seismic 

Rehabilitation of Buildings, Second Edition, 

FEMA 156 and 157 Reports, Federal 
138 References FEMA 154 

Emergency Management Agency, 

Washington, D.C. 

ICBO, 1973, 1997, Uniform Building Code, 

International Conference of Building Officials, 

Whittier, California.

NBS, 1980, Development of a Probability Based 

Load Criterion for American National 

Standard A58.1, NBS Special Publication 577, 

National Bureau of Standards, Washington, 

D.C. 

NIBS, 1999, Earthquake Loss Estimation 

Methodology HAZUS, Technical Manual, 

Vol. 1, prepared by the National Institute of 

Building Sciences for the Federal Emergency 

Management Agency, Washington, D.C. 

ROA, 1998, Planning for Seismic Rehabilitation: 

Societal Issues, developed for the Building 

Seismic Safety Council, by Robert Olson 

Associates, Inc., for the Federal Emergency 

Management Agency, FEMA-275 Report, 

Washington, D.C. 

SAC, 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, FEMA 350 Report, 

Washington, D.C. 

VSP, 1994, Seismic Rehabilitation of Federal 

Buildings: A Benefit/Cost Model; Volume 1: A 

Users Manual and Volume 2: Supporting 

Documentation; prepared by VSP Associates, 

Sacramento California, for the Federal 

Emergency Management Agency, FEMA-255 

and FEMA-256 Reports, Washington, D.C. 

Web pages 

Sanborn Map Company 

www.sanbornmap.com 

www.lib.berkeley.edu/EART/sanborn.html 
FEMA-154 Project Participants 139 

Project Participants 

Project Management

Mr. Christopher Rojahn (Principal Investigator) 

Applied Technology Council 

555 Twin Dolphin Drive, Suite 550 

Redwood City, California 94065 

Dr. Charles Scawthorn (Co-Principal 

Investigator and Project Director) 

ABS Consulting 

1111 Broadway, 10th Floor 

Oakland, California 94607 

FEMA Management

Mr. Ugo Morelli 

Federal Emergency Management Agency 

500 C Street, Room 416 

Washington, DC 20472 

Project Advisory Panel 

Prof. Thalia Anagnos 

(San Jose State University) 

2631 South Court 

Palo Alto, California 94306 

Mr. John Baals, Seismic Safety Program 

Coordinator, U.S. Department of the Interior 

Bureau of Reclamation 

Denver Federal Center, Building 67 

P.O. Box 25007, D-8110 

Denver, Colorado 80225-0007 

Mr. James Cagley* 

Cagley & Associates 

6141 Executive Blvd. 

Rockville, Maryland 20852 

Mr. Melvyn Green 

Melvyn Green & Associates 

21307 Hawthorne Blvd., Suite 250 

Torrance, California 90503 

Mr. Terry Hughes, CBO 

Code Specialist 

Hnedak Bobo Group, Inc. 

104 South Front Street 

Memphis, Tennessee 38103 

Prof. Anne S. Kiremidjian 

(Stanford University) 

1421 Berry Hills Court, 

Los Altos, California 94305 

Ms. Joan MacQuarrie 

Chief Building Official 

City of Berkeley 

2120 Milvia Street 

Berkeley, California 94704 

Mr. Chris D. Poland 

Degenkolb Engineers 

225 Bush Street, Suite 1000 

San Francisco, California 94104 

Prof. Lawrence D. Reaveley 

(University of Utah) 

1702 Cannes Way 

Salt Lake City, Utah 84121 

Mr. Doug Smits 

Chief Building/Fire Official 

City of Charleston 

75 Calhoun Street, Division 320 

Charleston, South Carolina 29401 

Mr. Ted Winstead 

Winstead Engineering, Inc. 

2736 Gerald Ford Drive, East 

Cordova, Tennessee 38016 *

ATC Board Contact 
140 Project Participants FEMA-154

Technical Consultants 

Mr. Kent David 

ABS Consulting 

1111 Broadway, 10th Floor 

Oakland, California 94607-5500 

Dr. Stephanie A. King 

Weidlinger Associates 

4410 El Camino Real, Suite 110 

Los Altos, California 94022 

Mr. Vincent Prabis 

ABS Consulting 

1111 Broadway, 10th Floor 

Oakland, California 94607-5500 

Mr. Richard Ranous 

ABS Consulting 

300 Commerce Drive, Suite 200 

Irvine, California 92602 

Dr. Nilesh Shome 

ABS Consulting 

1111 Broadway, 10th Floor 

Oakland, California 94607-5500 

Workshop Consultants 

Mr. William Holmes (Facilitator) 

Rutherford & Chekene 

427 Thirteenth Street 

Oakland, California 94612 

Dr. Keith Porter (Recorder) 

California Institute of Technology 

1200 E. California Blvd., MC 104-44 

Pasadena, California 91125 

Report Production and Editing 

Dr. Gerald Brady 

Applied Technology Council 

555 Twin Dolphin Drive, Suite 550 

Redwood City, California 94065 

Mr. Peter Mork 

Applied Technology Council 

555 Twin Dolphin Drive, Suite 550 

Redwood City, California 94065 

Ms. Michelle Schwartzbach 

Applied Technology Council 

555 Twin Dolphin Drive, Suite 550 

Redwood City, California 94065