FEMA

Substantial Improvement/

Substantial Damage 

Desk Reference

FEMA P-758 / May 2010

Substantial 

Improvement/ 

Substantial Damage 

Desk Reference

FEMA P-758 / May 2010

SI/SD Desk Reference

Preface

When buildings undergo repair or improvement, it is an opportunity for local flo

management programs to reduce flood damage to existing structures. More than 21,000 communities participate in the National Flood Insurance Program (NFIP), which is m

the Federal Emergency Management Agency (FEMA). To participate in the NFIP, communi

must adopt and enforce regulations and codes that apply to new development in Special Flo

Hazard Areas (SFHAs). Local floodplain management regulations and codes contain min

NFIP requirements that apply not only to new structures, but also to existing structures wh

are “substantially improved (SI)” or “substantially damaged (SD)

Enforcing the SI/SD requirements is a very important part of a community’s floodplain management responsibilities. There are many factors that local officials will need to 

several scenarios they may encounter while implementing the SI/SD requirements. This

Reference provides practical guidance and suggested procedures to implement the NFIP requirements for SI

This Desk Reference provides guidance on the minimum requirements of the NFIP regula

State or locally-adopted requirements that are more restrictive take precedence (often referr

to as “exceeding the NFIP minimums” or “higher standard

SI/SD Desk Reference i

Acknowledgments

FEMA would like to thank the following individuals who provided information, data, review, 

and guidance in developing this publication.

John Ingargiola 

FEMA Building Science Branch

Lois Forster

FEMA Floodplain Management Branch

Jack Anderson 

FEMA Regional and Disaster Support 

Branch

Jhun de la Cruz

FEMA Underwriting Branch

Lilah Haxton

FEMA Grants Policy Branch

Mary Colvin

FEMA Region II

Alan Springett 

FEMA Region II

Henry Chau

FEMA Region III

Joseph Zagone

FEMA Region III

Judy Marvel

FEMA Region IV

John Plisich

FEMA Region IV

Ross Richardson 

FEMA Region VI

Roger Connell 

FEMA Region VII

Mark Marik 

Formerly FEMA Region IX 

Michael Powell 

Delaware Department of Natural Resources 

and Environmental Control

Lisa Jones

South Carolina Department of Natural 

Resources

Ken Ford

Formerly National Association of Home 

Builders, Inc. 

Kim Paarlberg 

International Code Council, Inc.

Tom McDonald 

City of Savannah, GA

Tom Richards 

City of Findlay, OH 

Tim Condit 

Pikes Peak Regional Building Department. 

CO

Bob Croft 

Pikes Peak Regional Building Department.

CO

Jeannine Lewis 

Pikes Peak Regional Building Department. 

CO

Tom Leatherbee 

Del City, OK

Christopher P. Jones, P.E.

Consultant

Rebecca C. Quinn

RCQuinn Consulting, Inc.
iv SI/SD Desk Referenc

Acknowledgments

Jimmy Yeung

Greenhorne & O’Mara, Inc.

Hilary Kendro

Greenhorne & O’Mara, Inc.

Deb Daly

Greenhorne & O’Mara, Inc.

Julie Liptak

Greenhorne & O’Mara, Inc.
Table of Contents

Preface.........................................................................................................................................i

Acknowledgments............................................................................................................. iii

Chapter 1

1 Introduction......................................................................................................................... 1-1

1.1 Overview ............................................................................................................................. 1-1

1.2 What is Covered in This Desk Reference?.........................................................................1-2

1.3 Relevant Requirements.......................................................................................................1-3

1.4 Answers to Questions About SI/SD...................................................................................1-3

1.5 Where to Get Help..............................................................................................................1-4

Chapter 2

2 The NFIP: Roles and Responsibilities..................................................................................................... 2-1

2.1 Purposes and Overview of the NFIP.................................................................................. 2-1

2.2 The Community’s Role.......................................................................................................2-2

2.3 The State’s Role..................................................................................................................2-3

2.4 The Federal Role................................................................................................................2

Chapter 3

3 NFIP Substantial Improvement/Substantial Damage: Requirements and Definitions .............. 3-1

3.1 Overview.............................................................................................................................. 3-1

3.2 Introduction to the SI/SD Requirements......................................................................... 3-1

3.3 NFIP Regulations for SI/SD...............................................................................................3-2

3.4 Selected Definitions and Terms.........................................................................................3-4

3.4.1 Definitions: NFIP Regulations ...............................................................................3-5

3.4.2 Comparison of Definitions and Terms: NFIP and I-Codes...................................3-6

SI/SD Desk Reference
TABLE OF CONTENTS

Chapter 4

4 Making Substantial Improvement and Substantial Damage Determinations........................... 4-1

4.1 Overview.............................................................................................................................. 4-1

4.2 Accuracy and Verification...................................................................................................4-2

4.3 Making SI/SD Determinations .........................................................................................4-2

4.3.1 SI/SD Provisions in the 2006 and 2009 I-Codes ..................................................4-3

4.4 Determining Costs of Improvements and Costs to Repair...............................................4-4

4.4.1 Costs That Must be Included in SI/SD Determinations......................................4-5

4.4.2 Costs That May be Excluded from SI/SD Determinations..................................4-7

4.4.3 Acceptable Sources of Cost Information ..............................................................4-7

4.4.4 Estimates of Donated or Discounted Materials.....................................................4-8

4.4.5 Estimates of Owner and Volunteer Labor.............................................................4-8

4.4.6 Demolition and Construction Debris Disposal.....................................................4-9

4.4.7 Clean-up and Trash Removal ................................................................................4-9

4.4.8 Costs to Correct Existing Health, Safety, and Sanitary Code Violations..............4-9

4.5 Determining Market Value .............................................................................................. 4-11

4.5.1 Professional Property Appraisals..........................................................................4-13

4.5.2 Adjusted Assessed Value.......................................................................................4-14

4.5.3 Actual Cash Value.................................................................................................4-15

4.5.4 Qualified Estimates ..............................................................................................4-15

Chapter 5

5 Administering Substantial Improvement and Substantial Damage Requirements .................. 5-1

5.1 Overview.............................................................................................................................. 5-1

5.2 Community Responsibilities .............................................................................................. 5-1

5.3 Property Owner/Applicant Responsibilities.....................................................................5-2

5.4 Important Community Actions .........................................................................................5-3

5.5 Informing the Public..........................................................................................................5-4

5.5.1 Permit Application Forms......................................................................................5-4

5.5.2 Websites and Handouts..........................................................................................5-4

5.6 Administering the SI/SD Requirements...........................................................................5

vi SI/SD Desk Referenc
TABLE OF CONTENTS

5.6.1 Combinations of Types of Work.............................................................................5-5

5.6.2 Phased Improvements............................................................................................5-6

5.6.3 Incremental Repair of Damaged Buildings...........................................................5-7

5.6.4 Damaged Buildings.................................................................................................5-7

5.6.5 Special Circumstances (Damaged Buildings).......................................................5-8

5.6.6 Appeals of Decisions ..............................................................................................5-9

5.6.7 Variances to the Requirements .............................................................................5-9

5.6.8 Floodways............................................................................................................... 5-11

5.6.9 V Zones..................................................................................................................5-12

5.6.10 Coastal Barrier Resource Areas............................................................................5-12

5.6.11 Revisions of the FIRM ..........................................................................................5-13

5.6.12 Inspections............................................................................................................5-13

5.6.13 Enforcement and Violations................................................................................5-14

5.6.14 Recordkeeping......................................................................................................5-15

5.6.15 Issuing SI/SD Determination Letters..................................................................5-16

5.6.16 Rescinding SI/SD Determinations......................................................................5-16

5.7 Exceeding NFIP Minimum Requirements......................................................................5-17

5.7.1 Community Rating System...................................................................................5-17

5.7.2 Lower Threshold for SI/SD.................................................................................5-18

5.7.3 Cumulative SI/SD.................................................................................................5-19

5.8 Recommendations to Improve Flood Resistance ..........................................................5-20

Chapter 6

6 Factors to Consider and Illustrations of Substantial Improvement and Repair of 

Substantial Damage ...........................................................................................................6-1

6.1 Overview.............................................................................................................................. 6-1

6.2 Factors to Consider When Evaluating Permit Applications for Improvements

and Repairs ........................................................................................................................6-1

6.2.1 Pre-FIRM or Post-FIRM...........................................................................................6-1

6.2.2 A Zone or V Zone .................................................................................................. 6-2

6.2.3 More Than One Flood Zone ................................................................................ 6-3

6.2.4 Residential or Non-Residential............................................................................. 6-3

6.3 Bringing Substantially Improved and Substantially Damaged Buildings into

Compliance........................................................................................................................ 6-3

SI/SD Desk Reference v
TABLE OF CONTENTS

6.3.1 Lowest Floor Elevations..........................................................................................6-4

6.3.2 Enclosures...............................................................................................................6-5

6.3.3 Basements................................................................................................................6-6

6.3.4 Utility and Building Service Equipment................................................................6-6

6.3.5 Flood Damage-Resistant Materials.........................................................................6-7

6.3.6 Making Buildings Reasonably Safe from Flooding ..............................................6-7

6.4 Illustrations of Improvements and Repairs.......................................................................6-8

6.4.1 Rehabilitation and Remodeling...........................................................................6-10

6.4.2 Lateral Additions ..................................................................................................6-12

6.4.3 Vertical Additions .................................................................................................6-19

6.4.4 Repair, Reinforce, or Replace Foundations ....................................................... 6-21

6.4.5 Repair of Damaged Buildings..............................................................................6-22

6.4.6 Reconstruction of Demolished or Destroyed Buildings.....................................6-22

6.4.7 Work on Post-FIRM Buildings..............................................................................6-22

6.4.8 Work on Buildings Where Flood Maps Have Been Revised...............................6-22

6.5 Requirements for Certain Structures..............................................................................6-23

6.5.1 Historic Structures................................................................................................6-23

6.5.2 Manufactured Homes ..........................................................................................6-24

6.5.3 Accessory Structures and Certain Agricultural Structures.................................6-26

6.6 NFIP Flood Insurance Implications ................................................................................6-27

Chapter 7

7 Substantial Damage in the Disaster Recovery Environment.................................................. 7-1

7.1 Overview.............................................................................................................................. 7

7.2 Preparing for Post-Disaster Recovery................................................................................. 7-1

7.2.1 Sources of Assistance..............................................................................................7-2

7.3 Assessing Building Damage................................................................................................7-3

7.3.1 Preliminary Damage Assessments..........................................................................7-3

7.3.2 Rapid Evaluations and Detailed Safety Evaluations .............................................7-3

7.4 Using Estimates of Repair Costs and Market Values to Screen for Substantial

Damage............................................................................................................................... 7-4

7.4.1 Insurance Estimates of Repair Costs......................................................................7-5

7.4.2 Unadjusted Assessed Values as Estimates of Market Values.................................7-6

viii SI/SD Desk Referenc
TABLE OF CONTENTS

7.4.3 Replacement Cost Values as Estimates of Market Values.....................................7

7.5 Damage Assessments for Substantial Damage Determinations...................................... 7-6

7.5.1 FEMA’s Substantial Damage Estimator Software..................................................7-7

7.6 Increased Cost of Compliance Coverage...........................................................................7

7.7 Post-Disaster Permits and Inspections............................................................................. 7-11

7.8 Appeals and Variances...................................................................................................... 7-11

7.9 Post-Disaster Communications with Property Owners...................................................7-12

7.9.1 Information About Clean-up and Repairs...........................................................7-12

7.9.2 Information About Permits..................................................................................7-12

7.9.3 Information About Increased Cost of Compliance Coverage............................7-13

7.9.4 Interactions with the Public During Damage Assessments................................7-13

7.9.5 Providing Substantial Damage Determination Letters to Owners.....................7-14

Chapter 8

8 Mitigation Projects...................................................................................................................8-1

8.1 Overview.............................................................................................................................. 8-1

8.2 Mitigation Planning............................................................................................................ 8

8.3 Types of Flood Mitigation Projects ...................................................................................8-2

8.3.1 Identifying Flood Mitigation Projects....................................................................8-2

8.3.2 Property Acquisition/Demolition and Relocation...............................................8-3

8.3.3 Building Elevation ..................................................................................................8-3

8.3.4 Relocation................................................................................................................8-4

8.3.5 Floodproofing for Non-Residential Structures or Historic Structures ...............8-4

8.3.6 Other Types of Projects .........................................................................................8-4

8.4 FEMA’s Mitigation Grant Programs...................................................................................8-4

8.4.1 Elements Common to All Grant Programs...........................................................8-5

8.4.2 Pre-Disaster Mitigation Program............................................................................8

8.4.3 Hazard Mitigation Grant Program ........................................................................8-6

8.4.4 Flood Mitigation Assistance Program....................................................................8-7

8.4.5 Repetitive Flood Claims Program .........................................................................8-7

8.4.6 Severe Repetitive Loss Program.............................................................................8-8

8.5 Additional Information......................................................................................................8-9

SI/SD Desk Reference 
TABLE OF CONTENTS

Appendices

A. FEMA Regional Offices, NFIP State Coordinating Agencies, and State Hazard Mitigation

Offices

B. References

C Glossary and Acronyms

D Sample Notices to Property Owners, Sample Affidavits, and Other Material

E Sample Letters of Determination

Tables

Chapter 1

Table 1-1. Desk Reference Organization......................................................................................1-2

Chapter 3

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes ..............................3-7

Chapter 5

Table 5-1a. Tracking Cumulative Substantial Improvements, Determining Market Value for Each

Permit Application (shows increases in market value)..............................................................5-20

Table 5-1b. Tracking Cumulative Substantial Improvements, Determining Market Value for Each

Permit Application (shows decrease, then increase in market value).......................................5-20

Chapter 6

Table 6-1a. Compliance Matrix (A Zones)....................................................................................6-9

Table 6-1b. Compliance Matrix (V Zones)..................................................................................6-10

Table 6-2. Substantial Improvement and NFIP Flood Insurance Implications.........................6-28

Figures

Chapter 4

Figure 4-1. Make the SI/SD determination (overview)................................................................4-3

Figure 4-2. Determine the cost of work (overview)......................................................................4-5

Figure 4-3. Determine the market value (overview)...................................................................4-12

x SI/SD Desk Referenc
TABLE OF CONTENTS

Chapter 6

Figure 6-1. Rehabilitation or remodel (no increase in footprint) of residential building in

an A zone – the proposed work was determined to be a substantial improvement. ............... 6-11

Figure 6-2. Rehabilitation or remodel (no increase in footprint) of non-residential building

in an A zone – the proposed work was determined to be a substantial improvement. ...........6-12

Figure 6-3. Lateral addition to a pre-FIRM building in an A zone – the proposed work is only the

addition (no work was performed on the original building and no structural modification was

made to the common wall or roof). ...........................................................................................6-14

Figure 6-4. Lateral addition to a pre-FIRM building in an A zone – the proposed work includes

an addition and work on the original building, including structural modification of the common wall or roof. The proposed work was determined to be a substantial improvement.......6-14

Figure 6-5. Lateral addition to a residential building in a V zone – the proposed work includes

work on the original building. The lateral addition and improvements constitute substantial improvement.....................................................................................................................................6-15

Figure 6-6. Lateral addition to a pre-FIRM manufactured home in an A zone – the proposed work includes improvements to the existing home. The work constitutes substantial

improvement.................................................................................................................................6-16

Figure 6-7. Lateral addition to a non-residential building in an A zone – the proposed work is

only the addition (no work on the existing building and no structural modification of the common wall or roof). The work constitutes substantial improvement. ........................................6-17

Figure 6-8. Lateral addition to a post-FIRM building in any flood zone (map revision has

not changed the effective BFE). All improvements or repairs to a post-FIRM building must

comply with the NFIP requirements regardless of the value of that work................................6-18

Figure 6-9. Lateral addition to a post-FIRM building in an A zone (a map revision has increased

the BFE). The proposed work is a lateral addition with no work in the original building and no

structural modification of the common wall or roof..................................................................6-18

Figure 6-10. Vertical addition to a pre-FIRM residential building (in any zone) – the proposed work is a new upper story that involves structural modification. The work is a substantial

improvement. ...............................................................................................................................6-19

Figure 6-11. Vertical addition to a pre-FIRM residential building (in any zone) – the proposed work is a new lower story that involves structural modification. The work constitutes a

ubstantial improvement...............................................................................................................6-19

Figure 6-12. Vertical addition to a pre-FIRM, non-residential building in an A zone. The work

constitutes a substantial improvement........................................................................................6-20

Figure 6-13. New foundation or repair of foundation under a pre-FIRM (in an A zone)

residential building. The work was determined to be a substantial improvement. ................. 6-21

SI/SD Desk Reference 
TABLE OF CONTENTS

Figure 6-14. The cost of NFIP flood insurance policy varies depending on how a substantially

damaged building is repaired. This illustration is for $150,000 in structure coverage with the

rates as of October 2009. The figure is for comparison purposes only. ..................................6-29

Chapter 7

Figure 7-1. SDE data displayed using mapping software..............................................................7-9

xii SI/SD Desk Referenc
SI/SD Desk Reference 

1	 Introduction

1.1	 Overview

When buildings undergo repair or improvement, it is an opportunity for floodplain management programs to reduce flood damage to existing structures. More than 21,000 communities 

participate in the National Flood Insurance Program (NFIP) by adopting and enforcing regulations and codes that apply to development in Special Flood Hazard Areas (SFHAs). Local 

floodplain management regulations and codes contain minimum NFIP requirements that are 

not only for new structures, but also for existing structures with proposed “substantial improvements” or repair of “substantial damage.” 

Local officials in communities that participate in the NFIP must determine whether proposed 

work qualifies as a substantial improvement or repair of substantial damage (referred to as 

an “SI/SD determination”). If work on buildings constitutes SI/SD, then structures must be 

brought into compliance with NFIP requirements for new construction, including the requirement that lowest floors be elevated to or above the base flood elevation (BFE). Meeting this 

requirement can also be accomplished by demolition followed by construction of new buildings 

that meet the NFIP requirements on the same sites or by relocating buildings to locations outside of the SFHA. In some cases after a disaster, communities have worked with owners to buy 

damaged homes in order to demolish the buildings and preserve the land as open space. The 

NFIP defines SI/SD as follows: 

n Substantial improvement (SI) means any reconstruction, rehabilitation, addition, or other 

improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the 

structure (or smaller percentage if established by the community) before the “start of construction” of the 

improvement. This term includes structures that have incurred “substantial damage,” regardless of the 

actual repair work performed.

n Substantial damage (SD) means damage of any origin sustained by a structure whereby the cost 

of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the 

market value of the structure before the damage occurred. Work on structures that are determined to be 

substantially damaged is considered to be substantial improvement, regardless of the actual repair work 

performed.

The 50 percent threshold was chosen as a compromise between two extremes. One extreme 

would be to prohibit all investment in existing structures that do not meet minimum NFIP 

requirements. The other extreme would be to allow structures in flood hazard areas to be 

improved in any fashion without regard to the flood risk. In the first alternative, there is the 

potential for causing hardship to those who have located in flood hazard areas without knowledge of the risk because the structure was constructed prior to the designation of the area as 

flood-prone. These individuals would not be able to improve their structures as damage or age 

contributed to deterioration. The second alternative provides no mechanism to ensure that 

increased investment in flood hazard areas will receive needed protection from the flood risk, 
1- SI/SD Desk Referenc

1 INTRODUCTION

thus contributing to the increased peril to life and property. Thus, the threshold of 50 percent 

is a compromise at a half-way point and was chosen because it conforms to similar building code 

and zoning standards that also use this threshold. 

This Desk Reference is designed for local officials who are responsible for the administration of 

local codes and regulations, including the SI/SD requirements. It also is intended for State officials who provide technical assistance to communities on the NFIP.

1.2	 What is Covered in This Desk Reference?

Enforcing the SI/SD requirements is a very important part of a community’s floodplain management responsibilities. There are many factors that local officials will need to consider and 

several scenarios they may encounter while implementing the SI/SD requirements. This Desk 

Reference provides guidance and suggested procedures to implement the NFIP requirements 

for SI/SD. Table 1-1 summarizes the content of each chapter and lists the appendices. 

Table 1-1. Desk Reference Organization

Chapter Description of Content

1: Introduction Provides an overview of the Desk Reference, other relevant 

requirements, and suggestions for where to obtain additional help.

2: The NFIP: Roles and 

Responsibilities 

Outlines the purposes of the NFIP, offers an overview of how the 

program’s three components work together to support the long-term 

reduction of flood losses, and explains the roles and responsibilities 

of communities, State agencies, and the Federal Emergency 

Management Agency (FEMA). 

3: NFIP Substantial Improvement/

Substantial Damage: 

Requirements and Definitions

Provides an introduction to the NFIP’s SI/SD requirements and lists 

selected definitions and terms (and compares them with those of the 

building codes published by the International Code Council, Inc. [ICC]). 

4: Making Substantial Improvement 

and Substantial Damage 

Determinations

Explains how costs of improvements, costs of repairs, and market 

values are used to make the SI/SD determination, and describes ways 

to obtain or to estimate costs and values.

5: Administering Substantial 

Improvement and Substantial 

Damage Requirements

Outlines community and property owner responsibilities and 

provides detailed guidance for local officials who are responsible for 

administering and enforcing the SI/SD requirements.

6: Factors to Consider and 

Illustrations of Substantial 

Improvement and Repair of 

Substantial Damage

Describes the key aspects of bringing buildings into compliance with 

all of the NFIP requirements and illustrates examples of improvements 

and repairs. 

7: Substantial Damage in the 

Disaster Recovery Environment

Offers suggestions to prepare for disasters, an overview of the postdisaster process, methods to estimate costs and market values after 

major disasters, and describes FEMA’s Substantial Damage Estimator.

8: Mitigation Projects Describes the most common types of mitigation projects and briefly 

summarizes FEMA’s five mitigation grant programs.
SI/SD Desk Reference 1

INTRODUCTION 1

Appendices Description of Content

Appendix A FEMA Regional Offices, NFIP State Coordinating Agencies, and State 

Hazard Mitigation Offices

Appendix B References 

Appendix C Glossary and Acronyms

Appendix D Sample Notice to Property Owners, Worksheet, and Other Material

Appendix E Sample Letters of Determination

1.3	 Relevant Requirements

This Desk Reference provides guidance on the minimum 

requirements of the NFIP regulations. State or locally-adopted requirements that are more restrictive take 

precedence (often referred to as “exceeding the NFIP 

minimums” or “higher standards”).

Many States and communities have adopted one or more 

of the codes in the family of codes published by the International Code Council, Inc. (I-Codes®) or use the I-Codes 

as the basis of their own codes. These codes contain 

provisions for buildings in flood hazard areas, including provisions related to substantial improvement and 

substantial damage. The pertinent codes are the International Building Code® (IBC®), International Residential Code®

(IRC®), and International Existing Building Code® (IEBC®). Each references Flood Resistant Design 

and Construction (ASCE 24-05), the national consensus standard produced by the American Society of Civil Engineers, Inc. (ASCE).

1.4	 Answers to Questions About SI/SD

FEMA 213, Answers to Questions about Substantially Damaged Buildings, is a FEMA publication that

summarizes answers to certain key questions regarding substantial damage and a few questions 

related to substantial improvement. This SI/SD Desk Reference provides expanded discussion 

and more detailed guidance on making substantial damage determinations, along with detailed 

guidance on administering the substantial improvement requirements. 

The most common floodplain management requirement that exceeds 

NFIP minimums and also applies to 

SI/SD is freeboard – added height 

to raise the lowest floor above the 

BFE. 

Communities that have a building 

code and floodplain management 

regulations must administer the 

more restrictive provisions. 

Table 1-1. Desk Reference Organization (continued)
1- SI/SD Desk Referenc

1 INTRODUCTION

1.5	 Where to Get Help

Each State has a designated State Coordinating Agency for the NFIP, with an individual identified as the NFIP State Coordinator. State Coordinators provide a link between the Federal 

government and local governments on matters related to floodplain management. Additional 

assistance may be sought from FEMA’s Regional Offices. Appendix A includes contact information for FEMA Regional Offices, NFIP State Coordinating Agencies, and State Hazard Mitigation 

Offices.

FEMA produces extensive guidance materials and publications related to floodplain management. Many NFIP State Coordinating Agencies also publish guidance documents. Appendix 

B lists references pertinent to administering the SI/SD requirements and other resources for 

managing development in floodplains. FEMA publications are available from the FEMA library 

at http://www.fema.gov/library or by calling 1-800-480-2520.
SI/SD Desk Reference 2

2	 The NFIP: Roles and

Responsibilities

2.1	 Purposes and Overview of the NFIP

The original authorizing legislation for the NFIP was passed in 1968. Congress expressly found

that “a program of flood insurance can promote the public interest by encouraging sound land 

use by minimizing exposure of property to flood losses...” 

Thte NFIP is intended to encourage States and local governments to recognize and incorporate flood hazards in their land use and development decisions. In some communities, this is 

achieved by guiding development to areas with lower risk. When a proposal is made to develop 

within a flood hazard area, application of the criteria set forth in Federal regulation (Title 44 

Code of Federal Regulations [CFR] Section (§) 60.3) is intended to minimize exposure and 

flood-related damage.

The NFIP is administered by FEMA, which is part of the Department of Homeland Security 

(DHS). The NFIP has three main elements:

1. Hazard identification and mapping, in which engineering studies are conducted and

flood maps are prepared to delineate areas that are predicted to be subject to flooding 

under certain conditions; 

2. Floodplain management criteria, which establish the minimum requirements for communities to adopt and apply to development within mapped flood hazard areas; and 

3. Flood insurance, which provides financial protection for property owners to cover floodrelated damage to buildings and contents. 

Federal flood insurance is designed to provide an alternative to disaster assistance and disaster 

loans for home and business owners. Disaster assistance rarely comes close to covering all of 

the costs to repair and clean up. While available to qualified victims, disaster loans do not significantly ease the financial burden due to repayment terms. It is important to remember that 

disaster assistance is available only after floods have been declared major disasters by the President of the United States. In contrast, flood insurance claims will be paid any time damage from 

a qualifying flood event occurs. 

Another important objective of the NFIP is to break the cycle of flood damage. Many buildings 

have been flooded, repaired or rebuilt, and flooded again. In some parts of the country, this 

cycle occurs every couple of years. Before communities adopted floodplain management regulations, people tended to rebuild in the same flood-prone areas using the same construction 

techniques that did not adequately protect the structure when the first event occurred. On the 
2- SI/SD Desk Referenc

2 THE NFIP: ROLES AND RESPONSIBILITIES

other hand, structures built to NFIP floodplain management requirements experience, on average, 80 percent less damage through reduced frequency of inundation and severity of losses. 

By encouraging communities to guide development to lower risk areas, and by requiring the 

elevation of new buildings and certain existing buildings, one of the long-term objectives of the 

NFIP can be achieved: reducing flood damage and losses. Older buildings may be removed or 

replaced, or they may be upgraded or modified with techniques that lead to little or no flood 

damage.

The NFIP establishes distinct responsibilities for the Federal, State, and local levels of government. For local officials who must administer the SI/SD requirements of their regulations and 

codes, it is important to recognize how these established roles affect responsibilities for SI/SD. 

As outlined in the NFIP regulations:

n Communities are responsible for regulating all development in mapped flood hazard 

areas, issuing permits, and enforcing the requirements, including SI/SD requirements for 

improvements and repairs of buildings.

n States generally are responsible for providing technical assistance to communities, 

monitoring community programs, and coordinating between communities and the NFIP. 

Some States also administer regulatory programs and many are engaged in flood hazard 

mapping initiatives.

n FEMA, through administration of the NFIP, promulgates the minimum regulatory 

requirements, supports State programs, provides technical assistance, monitors community 

programs, and produces flood hazard maps.

2.2	 The Community’s Role

The NFIP regulations contained in 44 CFR § 59.22 and § 60.3 outline the responsibilities that 

communities must accept in order to become and remain eligible to participate in the NFIP. 

The key responsibilities include:

n Designate an agency that is charged with the responsibility to administer floodplain 

management requirements

n Determine whether proposed development activities are located in SFHAs

n Review development proposals to ensure compliance with the requirements of applicable 

floodplain management regulations and building codes

n Require that new subdivisions and development proposals with more than 50 lots or larger 

than five acres include BFEs

n Issue or deny permits for floodplain development

n Inspect all development in SFHAs to ensure compliance

n Maintain records of issued permits, elevation data, inspections, and enforcement actions

n Assist in the preparation and revision of floodplain maps
SI/SD Desk Reference 

THE NFIP: ROLES AND RESPONSIBILITIES 2

n Help residents obtain information on flood hazards, floodplain map data, and compliant 

construction measures 

For existing buildings that are located in SFHAs, community responsibilities include the following, in addition to the requirements above:

n Determine whether proposed improvements are “substantial improvements;” substantial 

improvement of buildings triggers requirements for permits and compliance.

n Determine whether work necessary to restore a damaged building to its pre-damage condition 

constitutes repair of “substantial damage;” repair of substantially damage buildings triggers 

requirements for permits and compliance.

Chapter 3 describes the NFIP SI/SD requirements and definitions. Chapter 4 outlines making 

SI/SD determinations; Chapter 5 outlines community responsibilities that are specifically related to administering these requirements. Chapter 6 includes factors to be considered when 

determining SI/SD and illustrations of substantial improvement and substantial damage. More 

guidance on administering and enforcing all aspects of local floodplain management regulations is found in FEMA 480, NFIP Floodplain Management Requirements: A Study Guide and Desk 

Reference. Chapter 7 suggests actions that communities can take to prepare for disasters, methods communities can use to obtain the costs to restore the structure and the market value of the 

structure before the damage occurred to make a substantial damage determination, and also 

describes a tool that communities can use to facilitate collecting data to make substantial damage determinations, FEMA’s Substantial Damage Estimator.

2.3	 The State’s Role

Each State’s governor has designated an NFIP State Coordinating Agency. This agency, often 

referred to as the NFIP State Coordinator’s Office, is specifically charged with being a link between Federal, State, 

and local governments. The NFIP State Coordinator stays 

current on NFIP issues and can advise communities on 

specific provisions and any State requirements. 

While the explicit role of the NFIP State Coordinator may 

vary among States, the NFIP regulations [44 CFR § 60.25] 

outline the following key responsibilities:

n Encourage and provide assistance for communities to 

qualify for participation in the NFIP

n Guide and assist communities to develop, implement, and maintain floodplain management 

regulations

n Provide technical assistance to communities

n Participate in training opportunities 

Some States have their own floodplain management statutes and 

regulations, and some administer 

regulatory programs pertaining to 

flood hazards. State requirements 

related to work on existing buildings must be satisfied in addition 

to local requirements.
2- SI/SD Desk Referenc

2 THE NFIP: ROLES AND RESPONSIBILITIES

n Assist in the delineation of flood-prone areas

n Notify FEMA of problems with community programs, if such problems cannot be resolved 

through technical assistance

2.4 	 The Federal Role

Several Federal agencies have programs and responsibilities that relate to flooding, managing 

flood hazards, and responding to flood events. Only FEMA’s role is directly pertinent to the purpose of this Desk Reference. 

Located at FEMA Headquarters in Washington, DC, the Flood Insurance and Mitigation Administration (FIMA) implements the three main elements of the NFIP (flood hazard identification, 

floodplain management, and flood insurance). The Directorate sets National policy, issues interpretations, enrolls communities in the NFIP, researches floodplain construction practices, 

and administers the flood hazard mapping and flood insurance elements of the program. Specifically, FEMA develops publications to help States and participating communities fulfill their 

responsibilities and to provide guidance to property owners, architects, engineers, and others 

proposing to develop in the floodplain.

FEMA implements its program responsibilities through 10 Regional Offices. Each Regional Office has a Mitigation Division that works with States and communities on matters related to the

NFIP. Each Regional Office covers four to eight States and territories; together they work with 

over 21,000 participating communities. The responsibilities of the Regional Offices include

n Assist the NFIP State Coordinating Agencies

n Advise local officials responsible for administering floodplain management regulations

n Assess community compliance with the minimum NFIP criteria

n Answer questions from design professionals, builders, and the public

n Provide information about flood insurance and respond to questions from citizens

n Maintain and revise flood hazard maps and data

n Provide information and training on many aspects of the NFIP, including administration of 

the SI/SD requirements

n Work with States and communities to resolve identified problems with community 

programs 
SI/SD Desk Reference 3

3	 NFIP Substantial Improvement/

Substantial Damage:

Requirements and Definitions

3.1	 Overview

This chapter provides NFIP regulations for substantial improvement and substantial damage, 

and includes key definitions for implementing the SI/SD requirements (also see the glossary 

and acronyms in Appendix C). This chapter also compares the NFIP’s terminology with terms 

and definitions used in the I-Codes. 

3.2	 Introduction to the SI/SD Requirements

The NFIP includes a requirement that new buildings and substantially improved buildings be 

constructed in ways that minimize or prevent damage during a flood. This requirement grew 

out of the recognition that there were large numbers of buildings already located in floodprone areas that would continue to be subject to damage. 

The purpose of the SI/SD requirements is to protect the 

property owner’s investment and safety, and, over time, 

to reduce the total number of buildings that are exposed 

to flood damage, thus reducing the burden on taxpayers through the payment of disaster assistance. The SI/SD 

requirements are triggered when the local official determines that the cost of repairing or improving a building 

in an SFHA equals or exceeds 50 percent of the building’s 

market value (excluding land value). 

Types of work that may trigger SI/SD requirements are 

described in detail in Chapter 6 and generally include:

n Rehabilitation or remodeling of a building with or 

without modifying its external dimensions

n Lateral additions that may or may not involve structural 

modifications of a building

n Vertical additions 

n Repair of foundations, including replacing or extending foundations

The SI/SD requirement is similar to common zoning and code 

requirements that address nonconforming uses and structures. 

The non-conformance is allowed 

to continue until a triggering event 

occurs, such as a change in use 

or a proposal to undertake significant physical alterations. 

Understandably, owners are concerned about the costs of bringing 

buildings into compliance. NFIP 

flood insurance policies on buildings located in SFHAs include 

coverage that is available for buildings that are substantially damaged 

by flood. Called Increased Cost of 

Compliance (ICC), this coverage 

is described in Sections 5.6.4 and 

7.6. 
3- SI/SD Desk Referenc

3 NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 

n Restoration or repair of damage of any origin that is necessary to restore a building to its predamaged condition

n Reconstruction of demolished or destroyed buildings on the same site or on the same 

foundation

n Work on post-Flood Insurance Rate Map (FIRM) buildings

n Work on existing buildings where flood zones or floodways are revised

The intent of the SI/SD requirements is not to discourage routine maintenance. If work requires a permit, then the local official must review all of the work proposed and the cost of all 

work must be included in the project costs, including work that might otherwise be considered 

routine maintenance. 

Chapter 6 describes how building characteristics and details of proposed work relate to the SI/

SD requirements of local floodplain management regulations. 

3.3	 NFIP Regulations for SI/SD

The NFIP regulations are online at http://www.fema.gov/business/nfip/laws1.shtm. The following excerpts of the regulations pertain to new construction and substantial improvement.

The requirements state that communities shall: 

§ 60.3(a)(3) Review all permit applications to determine whether proposed building sites will be 

reasonably safe from flooding. If a proposed building site is in a flood-prone area, all new construction and substantial improvements shall (i) be designed (or modified) and adequately anchored to 

prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and 

hydrostatic loads, including the effects of buoyancy, (ii) be constructed with materials resistant to 

flood damage, (iii) be constructed by methods and practices that minimize flood damage, and (iv) 

be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and 

other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding;

§ 60.3(b)(4) Obtain, review and reasonably utilize any base flood elevation and floodway data 

available from a Federal, State, or other source, including data developed pursuant to paragraph 

(b)(3) of this section, as criteria for requiring that new construction, substantial improvements, or 

other development in Zone A on the community's FHBM or FIRM meet the standards in paragraphs 

(c)(2), (c)(3), (c)(5), (c)(6), (c)(12), (c)(14), (d)(2) and (d)(3) of this section;

§ 60.3(c)(2) Require that all new construction and substantial improvements of residential structures within Zones A1-30, AE and AH zones on the community's FIRM have the lowest floor 

(including basement) elevated to or above the base flood level, unless the community is granted an 

exception by the Administrator for the allowance of basements in accordance with § 60.6 (b) or (c);

§ 60.3(c)(3) Require that all new construction and substantial improvements of non-residential 

structures within Zones A1-30, AE and AH zones on the community's FIRM (i) have the lowest 
SI/SD Desk Reference 

NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 3

floor (including basement) elevated to or above the base flood level or, (ii) together with attendant 

utility and sanitary facilities, be designed so that below the base flood level the structure is watertight 

with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;

§ 60.3(c)(5) Require, for all new construction and substantial improvements, that fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in 

an area other than a basement and which are subject to flooding shall be designed to automatically 

equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. 

Designs for meeting this requirement must either be certified by a registered professional engineer or 

architect or meet or exceed the following minimum criteria: A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding 

shall be provided. The bottom of all openings shall be no higher than one foot above grade. Openings 

may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit 

the automatic entry and exit of floodwaters;

§ 60.3(c)(6) Require that manufactured homes that are placed or substantially improved within 

Zones A1-30, AH, and AE on the community's FIRM on sites

(i) Outside of a manufactured home park or subdivision,

(ii) In a new manufactured home park or subdivision,

(iii) In an expansion to an existing manufactured home park or subdivision, or

(iv) In an existing manufactured home park or subdivision on which a manufactured home has 

incurred "substantial damage" as the result of a flood, be elevated on a permanent foundation 

such that the lowest floor of the manufactured home is elevated to or above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist floatation 

collapse and lateral movement.

§ 60.3(c)(7) Require within any AO zone on the community's FIRM that all new construction and 

substantial improvements of residential structures have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as the depth number specified in feet on the 

community's FIRM (at least two feet if no depth number is specified);

§ 60.3(c)(8) Require within any AO zone on the community's FIRM that all new construction and 

substantial improvements of non-residential structures (i) have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as the depth number specified in 

feet on the community's FIRM (at least two feet if no depth number is specified), or (ii) together with 

attendant utility and sanitary facilities be completely floodproofed to that level to meet the floodproofing standard specified in § 60.3(c)(3)(ii);

§ 60.3(c)(10) Require until a regulatory floodway is designated, that no new construction, substantial improvements, or other development (including fill) shall be permitted within Zones A1-30 and 

AE on the community's FIRM, unless it is demonstrated that the cumulative effect of the proposed 

development, when combined with all other existing and anticipated development, will not increase 

the water surface elevation of the base flood more than one foot at any point within the community.
3- SI/SD Desk Referenc

3 NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 

§ 60.3(c)(12) Require that manufactured homes to be placed or substantially improved on sites in 

an existing manufactured home park or subdivision within Zones A-1-30, AH, and AE on the community's FIRM that are not subject to the provisions of paragraph (c)(6) of this section be elevated 

so that either :

(i) The lowest floor of the manufactured home is at or above the base flood elevation, or 

(ii) The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and 

be securely anchored to an adequately anchored foundation system to resist floatation, collapse, 

and lateral movement.

§ 60.3(d) [When floodways have been designated] (3) Prohibit encroachments, including fill, 

new construction, substantial improvements, and other development within the adopted regulatory 

floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in 

accordance with standard engineering practice that the proposed encroachment would not result 

in any increase in flood levels within the community during the occurrence of the base flood discharge;

§ 60.3(e)(4) [When V zones have been designated] Provide that all new construction and 

substantial improvements in Zones V1-30 and VE, and also Zone V if base flood elevation data is 

available, on the community's FIRM, are elevated on pilings and columns so that (i) the bottom of 

the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated to or above the base flood level; and (ii) the pile or column foundation and structure attached 

thereto is anchored to resist flotation, collapse and lateral movement due to the effects of wind and 

water loads acting simultaneously on all building components. Water loading values used shall be 

those associated with the base flood. Wind loading values used shall be those required by applicable 

State or local building standards. A registered professional engineer or architect shall develop or review the structural design, specifications and plans for the construction, and shall certify that the 

design and methods of construction to be used are in accordance with accepted standards of practice 

for meeting the provisions of paragraphs (e)(4) (i) and (ii) of this section.

§ 60.3(e)(5) Provide that all new construction and substantial improvements within Zones V1-30, 

VE, and V on the community's FIRM have the space below the lowest floor either free of obstruction 

or constructed with non-supporting breakaway walls, open wood lattice-work, or insect screening 

intended to collapse under wind and water loads without causing collapse, displacement, or other 

structural damage to the elevated portion of the building or supporting foundation system. [Note: 

specifications for breakaway walls not shown.]

3.4	 Selected Definitions and Terms

Some of the terms used in this Desk Reference are defined in the NFIP regulations and some 

have meanings that are based on common usage. This section compares the NFIP terms with 

those defined and used in the administrative and flood damage-resistant provisions of the 

family of building codes known as the I-Codes. The I-Codes include the International Building Code (IBC) International Residential Code (IRC), International Existing Building Code (IEBC), 
SI/SD Desk Reference 

NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 3

International Mechanical Code®, International Plumbing Code®, the International Fuel Gas Code®, and a 

number of other specialty codes.

3.4.1	 Definitions: NFIP Regulations

The following are the NFIP definitions of several terms used in this Desk Reference (also see 

Appendix C for a glossary of related terms and definitions): 

n Floodproofing means any combination of structural and non-structural additions, changes, or 

adjustments to structures that reduce or eliminate flood damage to real estate or improved real property, 

water and sanitary facilities, structures, and their contents.

n Historic structure means any structure that is:

(a) Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the 

requirements for individual listing on the National Register;

(b) Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical 

significance of a registered historic district or a district preliminarily determined by the Secretary to 

qualify as a registered historic district;

(c) Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or

(d) Individually listed on a local inventory of historic places in communities with historic preservation 

programs that have been certified either:

(1) By an approved state program as determined by the Secretary of the Interior or

(2) Directly by the Secretary of the Interior in states without approved programs.

n Lowest floor means the lowest floor of the lowest enclosed area (including basement). An unfinished 

or flood damage-resistant enclosure, usable solely for parking of vehicles, building access, or storage 

in an area other than a basement area is not considered a building's lowest floor; Provided, that such 

enclosure is not built so as to render the structure in violation of the applicable non-elevation design 

requirements of § 60.3.

n New construction means, for floodplain management purposes, structures for which the “start of 

construction” commenced on or after the effective date of a floodplain management regulation adopted 

by a community and includes any subsequent improvements to such structures.

n Substantial damage means damage of any origin sustained by a structure whereby the cost of restoring 

the structure to its before damaged condition would equal or exceed 50 percent of the market value of the 

structure before the damage occurred.

n Substantial improvement means any reconstruction, rehabilitation, addition, or other improvement 

of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the 

“start of construction” of the improvement. This term includes structures that have incurred “substantial 

damage,” regardless of the actual repair work performed. The term does not, however, include either:
3- SI/SD Desk Referenc

3 NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 

(1) Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official 

and which are the minimum necessary to assure safe living conditions or

(2) Any alteration of a “historic structure,” provided that the alteration will not preclude the structure's 

continued designation as a “historic structure.”

The definition of substantial improvement includes structures that have incurred substantial 

damage. Work necessary to restore a substantially damaged building to its pre-damage condition 

constitutes a substantial improvement; therefore, the NFIP regulations that refer to substantial 

improvement also include substantial damage.

3.4.2	 Comparison of Definitions and Terms: NFIP and I-Codes

FEMA has determined that the provisions in the I-Codes for the design and construction of 

flood damage-resistant buildings are consistent with the NFIP requirements. Adoption of a 

code based on one or more of the I-Codes does not, by itself, meet all of the NFIP requirements, largely because the model codes deal primarily with buildings and structures. To learn 

more about coordinating local floodplain management regulations with the I-Codes, contact 

the NFIP State Coordinating Agency or FEMA Regional Office listed in Appendix A. The International Code Council, in coordination with FEMA published Reducing Flood Losses Through the 

International Codes®: Meeting the Requirements of the National Flood Insurance Program for additional 

guidance. 

Many States and communities administer building codes that are based on the model I-Codes. 

Because the model codes include provisions for SI/SD and local regulations also include SI/SD 

provisions, it is important to compare terms. In communities that use both codes and regulations to regulate SFHA development, officials need to be familiar with terms used in each, and 

recognize that some terms are used in one but not the other. Some terms are defined while others are simply used in context with their common meaning. Table 3-1 compares terms that are

defined or used by the NFIP with terms used in the I-Codes. Some terms (noted “used in guidance documents”) are not defined by the NFIP, but are used in this Desk Reference and various 

guidance documents listed in Appendix B. 
SI/SD Desk Reference 3

NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 3

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes

NFIP IBC IRC IEBC

Addition Used in the NFIP 

definition of “substantial 

improvement.”

Common NFIP usage: 

an expansion of a 

building that increases 

the total square footage.

An extension or 

increase in floor area or 

height of a building or 

structure.

An extension or 

increase in floor area or 

height of a building or 

structure.

An extension or 

increase in floor area, 

number of stories, or 

height of a building or 

structure.

Addition, minor Not defined in NFIP 

regulations; used in 

guidance documents.

Common NFIP usage: 

an addition that, based 

on a determination, 

is not a “substantial 

improvement.”

Not used in the IBC; 

included in definition of 

“Addition.”

Not used in the IRC; 

included in definition of 

“Addition.”

Not used in the IEBC; 

included in definition of 

“Addition.”

Addition, lateral

or horizontal

Not defined in NFIP 

regulations; used in 

guidance documents.

Common NFIP usage: 

an addition that 

extends beyond the 

existing footprint. May 

be a minor addition or 

may be determined 

to be a “substantial 

improvement.”

Not used in the IBC; 

included in definition of 

“Addition.”

Not used in the IRC; 

included in definition of 

“Addition.”

Not used in the IEBC; 

included in definition of 

“Addition.”

Addition, vertical Not defined in NFIP 

regulations; used in 

guidance documents.

Common NFIP usage: 

an addition that extends 

a building upward, 

either by adding an 

upper story or by 

elevating the building inplace and constructing 

a new story underneath. 

May be determined 

to be a “substantial 

improvement;” less 

likely to be a minor 

addition.

Not used in the IBC; 

included in definition of 

“Addition.”

Not used in the IRC; 

included in definition of 

“Addition.”

Not used in the IEBC; 

included in definition of 

“Addition.”

NFIP National Flood Insurance Program

IBC International Building Code

IRC International Residential Code

IEBC International Existing Building Code
3- SI/SD Desk Referenc

3 NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 

NFIP IBC IRC IEBC

Alteration Not defined in NFIP 

regulations; used in the 

NFIP definitions “start 

of construction” and 

“historic structure.”

Used in NFIP guidance 

documents.

Any construction 

or renovation to an 

existing structure other 

than repair or addition.

Any construction 

or renovation to an 

existing structure other 

than repair or addition 

that requires a permit. 

Also, a change in a 

mechanical system that 

involves an extension, 

addition, or change 

to the arrangement, 

type, or purpose of the 

original installation that 

requires a permit.

Any construction 

or renovation to an 

existing structure 

other than a repair or 

addition. Alterations are 

classified as Level 1, 

Level 2, and Level 3.

Alteration,

Level 1

Not used by the NFIP. Not used in the IBC. Not used in the IRC. 403.1 Scope. Level 

1 alterations include 

the removal and 

replacement or the 

covering of existing 

materials, elements, 

equipment, or fixtures 

using new materials, 

elements, equipment, 

or fixtures that serve 

the same purpose. 

[Note: 601.3 requires 

alterations that 

constitute SI to comply 

with flood requirements 

of the IBC.]

Alteration,

Level 2

Not used by the NFIP. Not used in the IBC. Not used in the IRC. 404.1 Scope. Level 

2 alterations include 

the reconfiguration of 

space, the addition 

or elimination of any 

door or window, the 

reconfiguration or 

extension of a system, 

or the installation of any 

additional equipment. 

(Level 2 alternations 

must comply with the 

requirements for Level 

1 and Level 2.)

Alteration,

Level 3

Not used by the NFIP. Not used in the IBC. Not used in the IRC. 405.1 Scope. Level 

3 alterations apply 

where the work area 

exceeds 50 percent 

of the aggregate 

area of the building. 

(Level 3 alternations 

must comply with the 

requirements for Level 

1, Level 2, and Level 3.)

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes (continued)
SI/SD Desk Reference 3

NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 3

NFIP IBC IRC IEBC

Building,

Elevated-inPlace

Not defined in NFIP 

regulations; used in 

guidance documents.

Common NFIP usage: 

a building that is 

detached from its 

original foundation and 

reattached to a new 

elevated foundation at 

the same location.

Not used in the IBC 

(see Addition).

Not used in the IRC 

(see Addition).

Not used in the IEBC 

(see Addition).

Building,

Existing

Not defined in NFIP 

regulations; used in 

guidance documents.

NFIP usage: a building 

that pre-dates the 

community’s first 

floodplain management 

regulation (see PreFIRM).

[Existing structure 

means] A structure 

erected prior to the 

date of adoption of the 

appropriate code, or 

one for which a legal 

building permit has 

been issued. See also 

Section 1612.2.

[Existing building 

means] Existing 

building is a building 

erected prior to the 

adoption of this code, 

or one for which a legal 

building permit has 

been issued.

[Existing building 

means] A building 

erected prior to the 

date of adoption of the 

appropriate code, or 

one for which a legal 

building permit has 

been issued.

Building,

Relocated

Not defined in NFIP 

regulations; used in 

guidance documents.

Common NFIP usage: 

a building that is 

detached from its 

original foundation 

and moved to another 

location with a new 

foundation.

Not used in the IBC; 

scope of IBC includes 

the movement of 

buildings.

Not used in the IRC; 

scope of IRC includes 

movement of buildings.

409.1 Scope. Relocated 

buildings provisions 

shall apply to relocated 

or moved buildings. 

[1202.6 requires 

relocated buildings to 

comply with the flood 

requirements of the 

IBC.]

Habitable

(Habitable

Space)

Not defined in NFIP 

regulations; used in 

guidance documents.

Uses allowed for 

enclosures below the 

base flood elevation 

include parking of 

vehicles, building 

access, and storage.

A space in a building 

for living, sleeping, 

eating, or cooking. 

Bathrooms, toilet 

rooms, closets, halls, 

storage or utility spaces 

and similar areas 

are not considered 

habitable spaces. [Note: 

habitable spaces are 

not all equivalent to the 

uses allowed below the 

elevated buildings in 

SFHAs.]

A space in a building 

for living, sleeping, 

eating or cooking. 

Bathrooms, toilet 

rooms, closets, halls, 

storage or utility spaces 

and similar areas 

are not considered 

habitable spaces. [Note: 

habitable spaces are 

not all equivalent to the 

uses allowed below the 

elevated buildings in 

SFHAs.]

Terms not defined in 

the IEBC; default to 

definitions in the IBC.

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes (continued)
3-10 SI/SD Desk Referen

3 NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 

NFIP IBC IRC IEBC

Non-residential Not defined in NFIP 

regulations. Used in 

NFIP regulations and 

guidance documents; 

see “Residential.”

All occupancies other 

than “Institutional 

Group I,” “Residential 

Group R,” and dwellings 

within the scope of the 

IRC (see “Residential”).

[Note: From ASCE 

24-05, Non-residential 

– any building or 

structure or portion 

thereof that is not 

classified residential.]

The scope of the 

IRC includes only 

“detached one- and 

two-family dwellings 

and townhouses not 

more than three stories 

above-grade in height 

with a separate means 

of egress and their 

accessory structures.”

Terms not defined in 

the IEBC default to 

definitions in the IBC.

Pre-FIRM A building for 

which construction 

or substantial 

improvement occurred 

on or before December 

31, 1974, or before 

the effective date of an 

initial FIRM. 

Not used in the IBC. Not used in the IRC. Not used in the IEBC.

Post-FIRM A building for 

which construction 

or substantial 

improvement occurred 

after December 31, 

1974, or on or after the 

effective date of the 

initial FIRM, whichever 

is later. 

Not used in the IBC. Not used in the IRC. Not used in the IEBC.

Reconstruction Not defined in NFIP 

regulations; used in 

the NFIP definition 

of “Substantial 

Improvement.”

Common NFIP usage: 

rebuilding on same 

foundation. Another 

common usage 

refers to groundup reconstruction, 

including a new 

foundation. In both, the 

new building is treated 

as new construction.

Used in the IBC 

definition of “Repair.”

Used in the IRC 

definition of “Repair.”

Used in the IEBC 

definition of “Repair.”

Rehabilitation Not defined in NFIP 

regulations; used in 

the NFIP definition 

of “Substantial 

Improvement.”

Common NFIP usage 

(including “remodel”) to 

describe work that does 

not increase square 

footage.

Used only in the IBC 

flood damage-resistant 

provisions

[Appendix J, Existing 

Buildings and 

Structures] Any repair, 

renovation, alteration 

or reconstruction work 

undertaken in an 

existing building.

Used in the IRC flood 

damage-resistant 

provisions.

Any work, as described 

by the categories of 

work defined herein, 

undertaken in an 

existing building.

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes (continued)
SI/SD Desk Reference 

NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 3

NFIP IBC IRC IEBC

Renovation Not defined in NFIP 

regulations; used in 

guidance documents.

Dictionary definition is 

“to restore to a former 

better state (as by 

cleaning, repairing, or 

rebuilding).”

Used in the IBC 

definition of “Alteration.”

Used in the IRC 

definition of “Alteration.”

Used in the IEBC 

definition of “Alteration.”

Repair Not defined in NFIP 

regulations; used in 

the NFIP definition 

of “Substantial 

Improvement.”

Dictionary definition 

includes (a) act or 

process of repairing; (b) 

to restore by replacing 

a part or putting 

together what is torn or 

broken.

The reconstruction or 

renewal of any part 

of an existing building 

for the purpose of its 

maintenance.

The reconstruction or 

renewal of any part 

of an existing building 

for the purpose of its 

maintenance.

The restoration to good 

or sound condition of 

any part of an existing 

building for the purpose 

of its maintenance.

402.1 Scope. Repairs, 

as defined in Chapter 

2, include the patching 

or restoration or 

replacement of 

damaged materials, 

elements, equipment or 

fixtures for the purpose 

of maintaining such 

components in good 

or sound condition 

with respect to existing 

loads or performance 

requirements.

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes (continued)
3-12 SI/SD Desk Refere

3 NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 

NFIP IBC IRC IEBC

Residential Used (but not defined) 

in the NFIP regulations 

and guidance 

documents. 

308 Institutional Group 

I. Institutional Group I 

includes, among others, 

the use of a building or 

structure, or a portion 

thereof, in which 

people are cared for 

or live in a supervised 

environment, having 

physical limitations 

because of health or 

age are harbored for 

medical treatment or 

other care or treatment, 

or in which people are 

detained for penal or 

correctional purposes 

or in which the liberty 

of the occupants is 

restricted.

310.1 Residential 

Group R. Residential 

Group R includes, 

among others, the 

use of a building or 

structure, or a portion 

thereof, for sleeping 

purposes when 

not classified as an 

Institutional Group I 

or when not regulated 

by the International 

Residential Code

in accordance 

with Section 

101.2. Residential 

occupancies shall 

include the following: 

[NOTE: list that follows 

is not shown.]

R101.2 Scope. 

The provisions of 

the International 

Residential Code for 

One- and Two-family 

Dwellings shall apply 

to the construction, 

alteration, movement, 

enlargement, 

replacement, repair, 

equipment, use and 

occupancy, location, 

removal and demolition 

of detached one- and 

two-family dwellings 

and townhouses not 

more than three stories 

above-grade in height 

with a separate means 

of egress and their 

accessory structures.

Terms not defined in 

the IEBC; default to 

definitions in the IBC.

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes (continued)
SI/SD Desk Reference 3

NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 3

NFIP IBC IRC IEBC

Residential

(continued)

[NOTE: The term 

“residential is defined 

in ASCE 24-05, 

Residential – (1) 

buildings and structures 

and portions thereof 

where people live, 

or that are used for 

sleeping purposes 

on a transient or nontransient basis; (2) 

residential structures, 

including but not limited 

to one- and two-family 

dwellings, townhouses, 

condominiums, multifamily dwellings, 

apartments, congregate 

residences, boarding 

houses, lodging 

houses, rooming 

houses, hotels, motels, 

apartment buildings, 

convents, monasteries, 

dormitories, fraternity 

houses, sorority houses, 

vacation timeshare 

properties; and (3) 

institutional facilities 

where people are cared 

for or live on a 24-hour 

basis in a supervised 

environment, including 

but not limited to board 

and care facilities, 

assisted living facilities, 

halfway houses, group 

homes, congregate 

care facilities, social 

rehabilitation facilities, 

alcohol and drug 

centers, convalescent 

facilities, hospitals, 

nursing homes, mental 

hospitals, detoxification 

facilities, prisons, jails, 

reformatories, detention 

centers, correctional 

centers, and prerelease 

centers.]

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes (continued)
3-14 SI/SD Desk Refere

3 NFIP SUBSTANTIAL IMPROVEMENT/SUBSTANTIAL DAMAGE: REQUIREMENTS AND DEFINITIONS 

NFIP IBC IRC IEBC

Restoration Used in the NFIP 

definition of “Substantial 

Damage.”

Dictionary definition 

includes (a) an act 

of restoring or the 

condition of being 

restored; (b) bringing 

back to a former 

position or condition.

Used in the definition 

of “Historic structures” 

and requirements for 

historic buildings.

Not used in the IRC. Used in the IEBC 

definition of “Repair.”

Story Not used in the NFIP 

regulations.

“Lowest Floor” means 

the lowest floor of the 

lowest enclosed area 

(including basement). 

An unfinished or flood 

damage-resistant 

enclosure, usable solely 

for parking of vehicles, 

building access, or 

storage in an area other 

than a basement area 

is not considered a 

building's lowest floor; 

Provided, that such 

enclosure is not built 

so as to render the 

structure in violation 

of the applicable 

non-elevation design 

requirements of Section 

60.3.

That portion of a 

building included 

between the upper 

surface of a floor and 

the upper surface of the 

floor or roof next above 

(also see “Mezzanine” 

and Section 502.1). 

It is measured as 

the vertical distance 

from top to top of two 

successive tiers of 

beams or finished floor 

surfaces and, for the 

topmost story, from the 

top of the floor finish 

to the top of the ceiling 

joists or, where there is 

not a ceiling, to the top 

of the roof rafters.

That portion of a 

building included 

between the upper 

surface of a floor and 

the upper surface of the 

floor or roof next above.

Terms not defined in 

the IEBC; default to 

definitions in the IBC.

Table 3-1. Comparison of Definitions and Terms in the NFIP and I-Codes (continued)
SI/SD	DeSk	RefeRence	 4-1

4	 Making	Substantial	

Improvement	and	Substantial	

Damage	Determinations

4.1	 Overview

Administering the SI/SD requirements requires local offi cials to perform four major actions: (1) determine costs, 

(2) determine market values, (3) make SI/SD determinations, and (4) require owners to obtain permits to bring 

substantially improved or substantially damaged buildings into compliance with the fl oodplain management 

requirements. This chapter describes how to determine 

whether work is a substantial improvement or a repair of 

substantial damage. The fi rst step is to review estimates of 

the improvement or repair costs; this step involves deciding which costs to include and exclude. Next, the market 

value of the structure must be determined. There is more 

than one way to determine costs and market value, and 

the local offi cial must examine both for reasonableness and accuracy.

Communities must be prepared to explain to permit applicants how they make SI/SD determinations. Local offi cials should develop written procedures that can help them make and 

document consistent determinations and improve effi ciency, especially in the post-disaster period when large numbers of buildings may be damaged.

Chapter 5 outlines community responsibilities that are specifi cally related to administering these 

SI/SD requirements. Chapter 6 describes factors to consider when evaluating permit applications and all aspects of bringing substantially improved and substantially damaged buildings 

into compliance; it also includes illustrations of improvements and repairs.

Chapter  addresses handling substantial damage in the post-disaster period, with recommendations for planning ahead to be prepared for the added workload and demands on staff and 

resources. It describes some methods that can help communities focus their efforts when many 

damaged buildings may have to be evaluated. It also describes FEMA’s Substantial Damage Estimator (SDE) software that communities can use to collect information about damaged buildings in 

order to make substantial damage determinations. 

The I-Codes include, in the administrative provisions, two requirements 

pertinent to the data necessary to 

make SI/SD determinations. Applicants must:

n State the valuation of proposed 

work, and

n Give other data and information as required by the building 

offi cial.
4-2 SI/SD	DeSk	RefeRence	

4				MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS

4.2	 Accuracy	and	Verifi	cation

Costs of proposed repairs or improvements and market values are needed to determine whether proposed 

work is SI/SD. Methods for obtaining this information 

are described in Sections 4.4 and 4.5, respectively. Local offi cials are responsible for verifying that the data are 

complete and reasonable. The local offi cial is responsible for reviewing the validity of all cost estimates provided 

by applicants, whether prepared by licensed contractors, 

engineers, architects, professional cost estimators, or by 

property owners. When work is repair of damage, an inspection visit should be made to verify that the proposed 

work is all of the work that is necessary to restore the 

building to its pre-damage condition. 

To be consistent, local offi cials should document their decisions and the documentation 

should be retained in the community’s permit records. A sample worksheet that can be used 

to document SI/SD determinations is included in Appendix D. Maintaining good records and 

documentation is especially critical if a community has elected to administer a cumulative SI/

SD requirement (Section 5..3).

4.3	 Making	SI/SD	Determinations	

Work on buildings ranges from routine maintenance and 

minor repairs (which may not require permits) to work 

that costs more than 50 percent of a structure’s market 

value. Local offi cials who are responsible for administering their fl oodplain management regulations or codes are 

responsible for determining whether work is SI/SD. Other entities, such as insurance claims adjusters, may make 

estimates of damage for purposes of adjusting damage 

claims. However, an adjuster's estimate must not be used 

to make SI/SD determinations because the estimates of 

damage that determine the amount of a claim payment 

may not include all of the costs to repair the building to 

its pre-damage condition.

Figure 4-1 illustrates an overview of the steps in the SI/SD determination that are described in 

detail in this Desk Reference. Once the cost of the work and the market value of the structure 

have been determined, the local offi cial must make a fi nal determination. The work is SI/SD if 

the ratio of the cost of work to the market value equals or exceeds 50 percent:

Applicants may disagree with a 

community’s SI/SD determination. 

In these cases, the burden is on 

the applicant to provide improved 

cost estimates or to obtain a professional appraisal of market value. 

The local offi cial is responsible for 

reviewing the new information. In 

some cases, applicants may seek 

a formal appeal of the local offi -

cial’s decision (Section 5.6.6).

Consistency is important. Communities should decide in advance 

how they will handle signifi cant 

fl ood events and develop written 

procedures for making decisions. 

It is easier to defend SI/SD determinations if all applicants are 

treated the same, especially when 

many buildings have been damaged (see Chapter 7).

Cost of Improvement or Cost to Repair to Pre-Damage Condition

Market Value of Building

≥ 50%
SI/SD	DeSk	RefeRence	 4-3

MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS					4

Communities may use a combination of sources for the data needed to make SI/SD determinations. For example, a community may make SI/SD determinations based on applicant-supplied 

costs of repairs or improvements and community-obtained market values. 

4.3.1	 SI/SD	Provisions	in	the	2006	and	2009	I-Codes	

The IBC and IRC apply to new construction and also to alteration, movement, enlargement, 

replacement, and repair of existing buildings. The IBC, the IRC, and the IEBC include SI/SD 

provisions that are consistent with the NFIP’s requirements. The specifi c code provisions are 

described below: 

n IBC. The IBC relies on the defi nitions of “substantial improvement” and “substantial damage” 

in Section 1612. The code offi cial must determine whether any alteration, repair, or addition 

to existing buildings, or work associated with a change of occupancy or moved buildings, meets 

those defi nitions. Section 1612.1 states that “all new construction of buildings, structures, and 

portions of buildings and structures, including substantial improvement and restoration of 

substantial damage to buildings and structures, shall be designed and constructed to resist 

the effects of fl ood hazards and fl ood loads.” In addition, the requirements for existing 

buildings, including historic buildings, are found in IBC Chapter 34.

n IRC. The IRC contains detailed administrative provisions in Chapter 1:

n R105.3.1.1 Substantially improved or substantially damaged buildings and structures in 

areas prone to fl ooding. This section specifi es that the building offi cial shall examine 

Figure	4-1.	Make	the	SI/SD	determination	(overview)

Determine Cost of Work (Section 4.4)

Determine Market Value (Section 4.5)

Divide:

Cost of Work

Market Value

Issue SI/SD 

determination letter 

(Section 5.6.15)

Require compliance

(Chapter 6)

Encourage fl ood 

resistance for 

pre-FIRM buildings 

(Section 5.8)

Ensure work is compliant and does not cause 

any aspect originally required for compliance to 

become non-compliant 

(Section 6.4.7)

Is result

≥50%?

Is building

post-FIRM? 

(Section 6.2.1)

YES

YES

NO

NO
4- SI/SD Desk Referen

4 MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINAT

applications and prepare a finding with regard to the value of the proposed work. If 

the value equals or exceeds 50 percent of the market value of the building before the 

damage occurred or the improvement is started, the finding is provided to the board of 

appeals.

n R112.2.1 Determination of substantial improvement in areas prone to flooding. This 

section requires the board of appeals to determine if a proposal, referred to the board 

by the building official pursuant to Section R105.3.1.1, constitutes a substantial improvement (or repair of substantial damage). If the proposed work is found to be a substantial 

improvement or repair of substantial damage, the work must meet the requirements of 

Section R324 (Flood-Resistant Construction).

n IEBC. The IEBC is organized based on the nature of the work: repairs; repair of damaged 

buildings; alterations (Levels 1, 2, and 3); work associated with change of occupancy 

classification; additions (horizontal, vertical, new/raised foundations); and relocated or 

moved buildings. These characterizations of work are similar to those used in Chapter 6 

(also see Table 3-1, which lists the definitions and terms used in the IEBC). The provisions 

of the IEBC that pertain to flood resistance are all triggered by a determination of whether 

the work constitutes a substantial improvement or a repair of substantial damage. When 

that occurs, the IEBC requires the building to be brought into compliance with the flood 

damage-resistant provisions of the IBC (located in IBC Section 1612). The IEBC also includes 

provisions for historic structures that are located in SFHAs.

4.4	 Determining Costs of Improvements and Costs to Repair

The term “costs of improvements” includes the complete costs associated with all of the types of 

work that are described in Chapter 6. The term “costs to repair” includes the costs of all work 

necessary to restore a damaged building to its pre-damage condition. Both terms include the 

costs of all materials, labor, and other items necessary to perform the proposed work. Costs that 

must be included are described in Section 4.4.1 and certain costs that may be excluded are described in Section 4.4.2. Figure 4-2 illustrates the steps that local officials need to take in order 

to determine costs for making SI/SD determinations.

The term “substantial damage” refers to the repairs of all damage sustained and cannot reflect 

a level of repairs that is less than the amount of the damage sustained. If an owner does not 

intend to repair the damaged building right away or if the owner cannot afford to make all repairs immediately, the local official should inspect the property to determine whether, based on 

estimates, the work required to restore it to its pre-damage condition will constitute substantial 

damage. If this is the case, then the cost to repair is compared to the building’s market value 

and the local official should provide written notice to the owner of the substantial damage determination. The local official should include in the written notice information about obtaining 

permits and about the floodplain management requirements that must be met. Further, sometimes these buildings also are improved beyond their pre-damage condition. If proposed, then 

the cost of improvements must be included along with the cost to repair to make the SI/SD determination. Note that the substantial damage requirement applies regardless of the cause of 

damage, such as wind or fire.
SI/SD	DeSk	RefeRence	 4-5

MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS					4

Use the cost of work in the 

SI/SD determination 

(Section 4.3)

Determine cost of proposed 

work (Section 4.4)

The following topics related to determining costs will be 

covered in this section:

n Costs that must be included

n Costs that may be excluded 

n Acceptable sources of cost information

n Estimates of donated or discounted materials

n Estimates of owner and volunteer labor

n Demolition, debris, and disposal

n Clean-up and trash removal

n Cost exclusions to correct existing health, safety, and sanitary code violations

4.4.1	 Costs	That	Must	be	Included	in	SI/SD	Determinations

Items that must be included in the costs of improvement and the costs to repair are those that 

are directly associated with the building. The following list of costs that must be included is not 

intended to be exhaustive, but characterizes the types of costs that must be included:

n Materials and labor, including the estimated value of donated or discounted materials 

(Section 4.4.4) and owner or volunteer labor (Section 4.4.5)

n Site preparation related to the improvement or repair (e.g., foundation excavation or fi lling 

in basements)

n Demolition and construction debris disposal (Section 4.4.6)

Local offi cials will need to determine the necessary level of detail 

for the costs of improvements and 

costs of repairs from permit applicants or contractors in order to 

make a SI/SD determination. 

Figure	4-2.	Determine	the	cost	of	work	(overview)

Review application for improvements and/

or repairs to determine nature and extent of 

work, location of building, whether it is preor post-FIRM (Chapters 4 and 5)

Review cost estimates and ensure 

that all appropriate costs are 

included/excluded

If post-disaster screening (Section 7.4) 

indicates buildings may be 

substantially damaged, use FEMA’s SDE 

(Section 7.5) or other method to 

estimate costs
4- SI/SD Desk Referen

4 MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINAT

n Labor and other costs associated with demolishing, moving, or altering building components 

to accommodate improvements, additions, and making repairs

n Costs associated with complying with any other regulations or code requirement that is 

triggered by the work, including costs to comply with the requirements of the Americans 

with Disabilities Act (ADA)

n Costs associated with elevating a structure when the proposed elevation is lower than the 

BFE

n Construction management and supervision

n Contractor’s overhead and profit

n Sales taxes on materials

n Structural elements and exterior finishes, including:

n Foundations (e.g., spread or continuous foundation footings, perimeter walls, chainwalls, pilings, columns, posts, etc.)

n Monolithic or other types of concrete slabs

n Bearing walls, tie beams, trusses

n Joists, beams, subflooring, framing, ceilings

n Interior non-bearing walls

n Exterior finishes (e.g., brick, stucco, siding, painting, and trim)

n Windows and exterior doors 

n Roofing, gutters, and downspouts

n Hardware 

n Attached decks and porches

n Interior finish elements, including:

n Floor finishes (e.g., hardwood, ceramic, vinyl, linoleum, stone, and wall-to-wall carpet 

over subflooring)

n Bathroom tiling and fixtures

n Wall finishes (e.g., drywall, paint, stucco, plaster, paneling, and marble)

n Built-in cabinets (e.g., kitchen, utility, entertainment, storage, and bathroom)

n Interior doors

n Interior finish carpentry

n Built-in bookcases and furniture

n Hardware

n Insulation
SI/SD Desk Reference 4

MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS 

n Utility and service equipment, including:

n Heating, ventilation, and air conditioning (HVAC) equipment

n Plumbing fixtures and piping

n Electrical wiring, outlets, and switches

n Light fixtures and ceiling fans

n Security systems

n Built-in appliances

n Central vacuum systems

n Water filtration, conditioning, and recirculation systems

4.4.2	 Costs That May be Excluded from SI/SD Determinations

Items that can be excluded are those that are not directly associated with the building. The following list characterizes the types of costs that may be excluded: 

n Clean-up and trash removal (Section 4.4.7

n Costs to temporarily stabilize a building so that it is safe to enter to evaluate and identify 

required repairs

n Costs to obtain or prepare plans and specifications

n Land survey costs

n Permit fees and inspection fees 

n Carpeting and recarpeting installed over finished flooring such as wood or tiling

n Outside improvements, including landscaping, irrigation, sidewalks, driveways, fences, yard 

lights, swimming pools, pool enclosures, and detached accessory structures (e.g., garages, 

sheds, and gazebos) 

n Costs required for the minimum necessary work to correct existing violations of health, 

safety, and sanitary codes (Section 4.4.8)

n Plug-in appliances such as washing machines, dryers, and stoves

4.4.3	 Acceptable Sources of Cost Information

The costs of improvements and the costs to repair are necessary to make the SI/SD determination. The following are acceptable methods to determine the costs: 

n Itemized costs of materials and labor, or estimates of materials and labor that are prepared 

by licensed contractors or professional construction cost estimators. 

n Building valuation tables published by building code organizations and cost-estimating 

manuals and tools available from professional building cost-estimating services. These 

sources can be used as long as some limitations are recognized, notably that there are local 
4- SI/SD Desk Referen

4 MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINAT

variations in costs and the sources do not list all types and qualities of structures. These 

sources should not be used for structures that are architecturally unique, exceptionally large, 

or significantly different from the classes of structures that are listed.

n “Qualified Estimate” of costs that are prepared by the local official using professional 

judgment and knowledge of local and regional construction costs. This approach is most 

often used post-disaster when there are large numbers of damaged buildings and when 

permits must be quickly processed.

n Building owners may submit cost estimates that they prepare themselves. If the community is 

willing to consider such estimates, owners should be required to provide as much supporting 

documentation as possible (such as pricing information from lumber companies and 

hardware stores). In addition, the estimate must include the value of labor, including the 

value of the owner’s labor (Section 4.4.5). 

FEMA developed the Substantial Damage Estimator, summarized in Section 7.5, to provide estimates of building values and costs to repair. In general, this method is most often used in the

post-disaster period when local officials need to inspect large numbers of damaged structures 

and make many substantial damage determinations. 

4.4.4	 Estimates of Donated or Discounted Materials

To help make improvements or repairs to damaged homes, some organizations and individuals donate materials, and some companies donate or provide materials at a discount. The value 

placed on all donated or discounted materials should be equal to the actual or estimated cost 

of such materials and must be included in the total cost. Where materials or servicing equipment are donated or discounted below normal market values, the value should be adjusted to 

an amount that would be equivalent to that estimated through normal market transactions.

As part of the documentation required for a permit, the applicant should provide cost estimates 

of the value of donated or discounted materials based on actual or estimated costs. This estimate should be verified by the local official based on professional judgment and knowledge of 

local or regional material costs. Some communities help non-profit organizations and applicants make these estimates.

4.4.5	 Estimates of Owner and Volunteer Labor

The situations described in Section 4.4.4 that involve donated or discounted materials may also 

involve volunteer labor. Also, property owners may undertake fairly significant improvement 

and repair projects on their own. In both cases, the normal “market” value or “going rate” for 

labor must be included in the estimates of the cost of improvements and the costs to repair. After significant events, labor rates may change and should be taken into account.

Labor rates vary geographically and by the nature of the work and trade required. As part of 

the documentation required for a permit, the applicant should provide an estimate of the value 

of owner or volunteer labor. The value placed on labor should be estimated based on applicable minimum-hour wage scales for the skill and type of construction work that is done. This 
SI/SD Desk Reference 4

MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS 

estimate should be verified by the local official based on professional judgment and knowledge 

of the local or regional construction industry wage scales. Some communities help non-profit 

organizations and permit applicants make these estimates.

4.4.6	 Demolition and Construction Debris Disposal

Demolition and construction debris disposal is not the same as clean-up and trash removal (Section 4.4.7). Virtually any type of work on a building requires some demolition. It may be as little

as removing the flooring or an interior wall, or as much as complete removal of a portion of the 

building and its foundation. Demolition may be part of an improvement project and usually is 

a necessary part of repairing damage. The costs of demolition, including the costs of disposal of 

the resulting debris, must be included in the cost of work for the purpose of making the SI/SD 

determination.

4.4.7	 Clean-up and Trash Removal

Clean-up and trash removal are distinguished from demolition and construction debris disposal (Section 4.4.6). Clean-up and trash removal costs are not included in the costs used in the 

SI/SD determination because they are not related to the actual cost of improving or repairing 

a building. 

Clean-up costs include such work as draining a basement; removing dirt and mud; and cleaning, 

disinfecting, and drying out buildings. Trash removal includes disposing of trash piled in the interior of the building or accumulated on the lot and related costs (e.g., dumpster, hauling, and 

tipping fees), as well as removal of abandoned contents and debris related to general clean-up 

of the structure before the improvement or repairs can be performed. 

If clean-up and trash removal are done at the same time as demolition and construction debris 

disposal, a cost estimate should clearly distinguish between costs that must be included and 

costs that may be excluded. Local officials can:

n Require property owners to submit itemized costs from all contractors, clearly identifying 

the costs related to trash disposal and clean-up from those related to demolition necessary 

to perform the work on the building, or 

n Based on judgment and knowledge of local costs, estimate the amounts to be excluded. The 

permit record should contain documentation of the basis for making this estimate.

4.4.8	 Costs to Correct Existing Health, Safety, and Sanitary Code Violations

The definition of substantial improvement provides an exclusion for “[a]ny project for improvement of a structure to correct existing violations of State or local health, sanitary, or safety code 

specifications which have been identified by the local code enforcement official and which are 

the minimum necessary to assure safe living conditions” (emphasis added). 

When deciding whether to exclude the costs to correct existing cited health, safety, and sanitary 

code violations, local officials must consider the following:
4-10 SI/SD Desk Referen

4 MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINAT

n Correct existing cited violations. The work must be:

n Limited to that necessary to correct an existing violation. This means that only work that 

is directly required for correction can be excluded from the costs of the proposed improvement or repair. All other work must be counted in the estimation of costs.

n Required to correct an existing violation. This means the condition considered in violation pre-dates the application for a permit (or the date of a damage event) and, 

importantly, an official who has the authority to enforce the community’s health, safety, 

and sanitary codes must have prior knowledge of the condition and must have verified 

that it constitutes a violation.

n Required to correct an existing violation. Violations of a community’s health, safety, and 

sanitary represent threats to public health and safety. Such conditions are considered violations only if they have been identified as violations. The mere presence of a condition 

that does not conform to current codes does not qualify as a violation.

n Identified by the local code enforcement official. To exclude certain costs from the SI/SD 

determination, an official who has the authority to enforce the community’s health and 

sanitary codes must have knowledge of and have identified the condition, and must have 

verified or determined that the condition constitutes a violation (normally, this involves 

issuing a citation or other official notice). Communities might not make a routine practice 

of inspecting structures in order to document and issue citations for violations. If likely 

violations of health and sanitary codes are identified by the property owner or contractor 

during the course of deciding what work to perform and before any improvements or repairs 

are made, the costs to address those code violations may be excluded, but only if the local 

official has made the determination that they can be excluded. 

n Minimum necessary to ensure safe living conditions. To qualify as excludable, the cost of 

correcting existing violations must be only those costs for the work that is the minimum 

necessary to address and resolve the violation. Costs of work in excess of the minimum 

necessary must be included in the SI/SD determination. 

For proper treatment of this substantial improvement exclusionary provision, a clear distinction must be made between violations and elements that simply do not meet the present-day 

design or building code standards. The following examples describe situations where the work 

performed to meet code requirements must be included in SI/SD determinations and some 

situations where costs may be excluded:

n Work on a building, or work associated with a change in use or occupancy, may trigger 

requirements for compliance with the current code. When this occurs, the costs associated 

with compliance do not qualify for exclusion because the work is not a code violation, but is 

necessary to meet current code. For example, consider an applicant who applies for a permit 

to perform work necessary for a change of occupancy from retail space to a restaurant. 

This will trigger certain code requirements and those costs must be included in the SI/SD 

determination. Costs that are related to compliance with current code requirements, but 

are not related to correcting existing violations must be included.
SI/SD Desk Reference 4-

MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS 

n The owner of a poorly insulated building proposes to rehabilitate it for a new occupant. 

Although the building does not conform to the current code for energy efficiency, the costs 

of adding insulation and other energy efficiency work must be included because the lack of 

adequate insulation is not a health and safety violation. 

n An owner proposes to improve a building and has applied for a permit. The owner presents 

the building official with evidence of termite damage. Termite damage is discovered in the 

floor joints and the joists are unable to safely support loads required by current code. The 

building official verifies that it constitutes a violation and cites it as a safety code violation. 

The minimum cost to correct this violation may be excluded if the violation was cited. If 

other building components have sustained termite damage that is not a safety code violation, 

such as damage to non-bearing wall studs and wall trim, the cost to address the damage must 

be included. 

n A restaurant’s plumbing system is failing and bathroom fixtures are inoperable. The 

condition is cited as a violation of the sanitary code. The owner proposes not only to correct 

the violation but make other improvements, including adding a second bathroom. The 

costs to correct the failing plumbing system and replace its fixtures may be excluded. The 

costs of the other improvements, including the second bathroom, must be included.

n In the course of inspecting an abandoned building, the code official cites several conditions 

as violations that must be corrected before the building can be reoccupied. The building 

is subsequently purchased and the new owner applies for a permit to not only address 

the violations, but also to rehabilitate the building. Only the costs to correct the cited 

violations that are explicitly related to health, sanitary, and safety code requirements may be 

excluded. All other costs associated with the rehabilitation must be included in the cost of 

improvements.

n The owner of a home has been notified that the home is not safe to occupy because of 

violations of the electrical code provisions. Rather than perform only the required repairs, 

the owner decides to completely renovate the home and submits an application that 

shows all renovation costs, while excluding the costs associated with all of the electrical 

work (including replacing all wiring and fixtures, installing more outlets, upgrading the 

panel board, etc.). The plan reviewer should catch this discrepancy. The only costs that may 

be excluded are those that are necessary to correct the violation – which means the costs 

associated with the code violation must be determined before they can be excluded from 

the SI/SD determination. All other costs associated with the upgrade of the electrical work 

must be included.

4.5	 Determining Market Value

For purposes of making SI/SD determinations, local officials need to determine the “market value” of structures in question. When work is an improvement, the market value is the 

building’s market value “before the ‘start of construction’ of the improvement.” When work is 

repair of substantial damage, the market value is the building’s market value “before the damage occurred.” If buildings have not been maintained and have deteriorated over time, then the 

market value is determined as of the date of the application for the permit to improve or repair 

the building.
4-12 SI/SD	DeSk	RefeRence	

4				MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS

The NFIP regulations do not defi ne “market value.” Generally, market value can be explained 

as the amount an owner would be willing but not obliged to accept, and that a buyer would be 

willing but not compelled to pay. The term may be defi ned by State statutes that pertain to zoning, property taxation, or real estate transactions.

Before reviewing options to determine the market value of a structure, it is important to note 

two basic NFIP requirements: 

n Market value must always be based on the condition of the structure before the improvement 

is undertaken or before the damage occurred. 

n Only the market value of the structure is pertinent. The value of the land and site 

improvements (landscaping, driveway, detached accessory structures, etc.) and the value of 

the use and occupancy (business income) are not included. Any value associated with the 

location of the property should be attributed to the land, not the building.

Many communities require the permit applicant to obtain an appraisal of market value from a 

qualifi ed professional who is licensed to perform appraisals in the State or community where 

the property is located (Section 4.5.1). In addition, three other methods to estimate market 

value are covered in this section:

n Assessed value developed for property tax assessment purposes, adjusted to approximate 

market value (Section 4.5.2) 

n Estimates of a structure’s actual cash value, including depreciation (Section 4.5.3)

n “Qualifi ed estimates” based on the professional judgment of a local offi cial (Section 4.5.4)

Figure 4-3 illustrates the steps local offi cials need to take in order to determine market values. 

Additional guidance on estimating market value following disasters is provided in Chapter .

Figure	4-3.	Determine	the	market	value	(overview)

Select method to estimate 

market value (Section 4.5)

● Professional appraisal (Section 4.5.1)

● Adjusted assessed value (Section 4.5.2)

● Actual cash value (Section 4.5.3)

● “Qualifi ed estimates” (Section 4.5.4)

● FEMA’s Substantial Damage Estimator 

(Section 7.5)

Use post-disaster screening 

to identify buildings that have 

sustained substantial 

damage (Section 7.4)

Use market value in 

SI/SD determination 

(Section 4.3)
SI/SD Desk Reference 4-

MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS 

4.5.1	 Professional Property Appraisals

Property appraisals that are prepared by a professional appraiser according to standard practices of the profession are the most accurate and reliable method for determining market value. 

Professional appraisers should be qualified to appraise the type of property (e.g., residential, 

commercial, industrial) and should be licensed in the State or community in which the property is located. Most States require professional property appraisers to be licensed and to perform 

valuation work in accordance with the quality control standards found in the Uniform Standards 

of Professional Appraisal Practice, which are maintained and administered by The Appraisal Foundation (http://www.appraisalfoundation.org). In those States that require use of the standards, 

local officials should check that market value appraisals prepared to support SI/SD determinations have a statement regarding conformance with this standard. 

Appraisal reports should identify intended users, including the property owner, who can then 

submit it as part of a permit application. In addition, the appraisal should be recent enough to 

reasonably reflect current market value as of the date of the permit application. When used to 

determine market value for damaged buildings, the appraisal must reflect the pre-damage condition. The “market approach” for determining market value works best if there are adequate 

market data and recent sales of comparable properties in the vicinity. Note that using the “income capitalization approach” is not acceptable because it is based on how the property is used, 

and not the value of structure alone. To separate the market value of a structure from the value 

of the land on which it is located, appraisers may need to do more research than is normally undertaken in order to reasonably allocate the total value between the structure and the land. 

The following are situations where the local official may require the applicant to provide a professional appraisal to determine the market value of a structure: 

n When it is written explicitly into the community’s floodplain management regulations or 

required by other local or State codes that independent appraisals shall be used for decisions 

related to non-conforming use permits.

n When the estimating methods that are used post-disaster (Section 7.4) yield a market value

that indicates that the cost of proposed work closely approaches 50 percent of the structure’s 

estimated market value.

n When an applicant disagrees with the community’s SI/SD determination. 

When a professional appraisal of market value is submitted, the local official is responsible for 

examining it to determine that it is reasonable for the specific characteristics of the building 

and to check that it does not include the value of land, land improvements (e.g., landscaping, 

paving), and accessory buildings. The market value of a non-residential building does not include the value of the use or occupancy. If there is cause to question the appraisal (for example, 

if it appears to overvalue the structure), the local official may request that another appraisal be 

provided.
4-14 SI/SD Desk Referen

4 MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINAT

4.5.2	 Adjusted Assessed Value

Generally, assessed values or property assessments are determined by the State or local taxing 

or assessment authority. The assessor’s job is to independently estimate the market value of real 

property. Assessments usually provide both land value and value of improvements, and are used 

as the basis for determining property taxes. Assessments are revised or adjusted periodically to 

account for changes in property values. The use of assessed value has some limitations that, if 

not considered and accounted for, can produce erroneous estimates of market value. These 

limitations are:

n Appraisal cycle. How often are the appraisals done and when was the date of the last appraisal? 

Market value estimates can be grossly outdated if the cycle is long and the property happens 

to be in the latter stage of its cycle and has not been appraised for many years.

n Land values. In most cases, land values and the value of improvements (structures) thereon 

will be assessed separately and listed as such in the tax records. In cases where they are not 

distinguished, a determination of the value of the land will have to be made and subtracted 

from the total assessed value.

n Assessment level. States and local taxing authorities vary in assessment levels (an established 

statutory ratio between the assessor's estimate of value and the true fair market value). 

For example, many States use an assessment level of 90 percent. In this case, the assessed

values will underestimate market values by 10 percent. In cases where the assessment level is 

unacceptably low or where the projected ratio of cost of repair to market value is close to 50 

percent, adjustments for assessment level must be made.

Local officials who elect to use assessed values for making SI/SD determinations should consult 

the authority that prepares the assessment values to understand the limitations on use of the 

data. Usually an adjustment factor is necessary because the assessed values cannot be used as a 

direct equivalent for current market value. The assessor’s office should provide the adjustment 

factor that, when applied to assessed value, yields the “adjusted assessed value” that can then be 

used as an estimate of market value. A copy of the adjustment factor justification should be retained with the community’s permanent records.

Adjusted assessed value may be used as a screening technique to separate out structures for which the ratio of 

repair or improvement costs to market value (adjusted assessed value) are obviously less than or greater than 50 

percent. In post-disaster situations where no other market value estimates are available or where the number of 

permit applications is overwhelming, unadjusted assessed 

values may have to suffice as the definitive estimate of 

market value. 

An owner may appeal the use of assessed value, but the burden of proof can be placed on the 

applicant who can be required to submit an independent professional property appraisal that 

is prepared by a qualified appraiser.

“Unadjusted assessed values” can 

be used to help local officials focus 

their efforts when large numbers of 

SD determinations must be made, 

such as after a disaster (Section 

7.3.2).
SI/SD Desk Reference 4-

MAKING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE DETERMINATIONS 

4.5.3	 Actual Cash Value

Actual cash value (ACV) is the cost to replace a building on the same parcel with a new building 

of like-kind and quality, minus depreciation due to age, use, and neglect. ACV does not consider 

loss in value simply due to outmoded design or location factors. The concept of ACV is used in 

both the insurance industry and the construction industry. In most situations, ACV is a reasonable approximation of market value. 

A number of commercial sources of construction cost information are available to support estimating the replacement cost of a building, including industry-accepted guides available from 

companies such as RSMeans (http://www.rsmeans.com) and the Craftsman Book Company 

(http://www.craftsman-book.com), among others. These sources allow computation of construction costs based on occupancy, square footage, quality, and regional cost variations.

Depreciation accounts for the physical condition of a structure. Depreciation does not take 

into account functional obsolescence (e.g., outmoded design or construction that pre-dates 

current codes) or factors that are external to the structure (e.g., reputation of schools or distance to shopping and parks). Commercially available references provide tables and formulas 

to calculate physical depreciation. These tables and formulas are objective and are used by most 

professionals in the fields of property appraisal and building inspection. Local officials may 

consult with a qualified appraiser regarding depreciation, or additional guidance for applying 

depreciation rates over time is found in FEMA P-784 CD, Substantial Damage Estimator (Section

7.5).

4.5.4	 Qualified Estimates

A “qualified estimate” of a structure’s market value is an estimate developed by a qualified local 

official who has sufficient experience and professional judgment on which to base such estimates. The local official may be in the building department or in the tax assessor’s office. The 

estimates should be made using the best available information, which may include recent permit 

records, recent home sales, regional cost data, estimates of depreciation based on knowledge 

of the pre-damage condition of buildings, and adjustments for unique or distinctive features of 

individual buildings. Another way that a local official may develop qualified estimates is if professional appraisals have been prepared for a few buildings; in that case, those results may be 

used to approximate the market values of similar buildings. This approach should be used only 

if the approaches described above cannot be used. Qualified estimates are most likely to be used 

in the post-disaster situation after large numbers of buildings have been damaged.

SI/SD Desk Reference 5

5	 Administering Substantial

Improvement and Substantial

Damage Requirements

5.1	 Overview

This chapter covers administrative topics, including community responsibilities and the responsibilities of property owners and permit applicants. It highlights options for informing the 

public about the SI/SD requirements and the need to get permits. Several matters that arise 

when reviewing permits are addressed in detail. 

Chapter 4 focused on making SI/SD determinations and the data that are necessary to make 

those determinations, including the cost of improvements, the cost of repairs, and the market 

value of buildings. Chapter 6 includes illustrations of SI/SD, and explains certain NFIP flood 

insurance implications related to SI/SD. Chapter 7 recommends ways to handle substantial 

damage in the post-disaster period, especially when many buildings are damaged. Chapter 8 

provides brief descriptions of common types of flood mitigation projects that may be eligible 

for funding by FEMA’s five Hazard Mitigation Assistance grant programs.

5.2	 Community Responsibilities

When a community decides to participate in the NFIP, it accepts the responsibility to adopt, 

administer, and enforce floodplain management provisions that either meet or exceed the minimum NFIP requirements. The following describes the responsibilities that specifically apply to 

administering the SI/SD requirements:

n Review permit applications to determine whether 

improvements or repairs of buildings in SFHAs 

constitute substantial improvement or repair of 

substantial damage. 

n Review descriptions of proposed work submitted 

by applicants to ensure that all requirements are 

addressed.

n Review cost estimates of the proposed work submitted 

by applicants and determine if the costs are reasonable for the proposed work, or use other 

acceptable methods to estimate the costs. 

n Decide the method to determine market value (including which method to use after an 

event that damages many buildings) and identify the buildings most likely to have sustained 

substantial damage.

Even if work on a building is determined to not constitute SI/SD, 

owners can do a lot to reduce 

future flood damage. Some recommendations that local officials 

may wish to encourage are listed 

in Section 5.8.
5- SI/SD Desk Referenc

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

n Review market value appraisals, if submitted by applicants, to determine if the appraisals 

reasonably represent the characteristics of the building and the market value of the structures 

(excluding land value). 

n Determine if proposed improvements are substantial 

improvements based on the costs of the proposed 

work compared to the market value of the building. 

n Determine if damaged buildings are substantially 

damaged based on cost estimates for repairs compared 

to the market value of the building before the damage 

occurred. 

n Issue a letter to the property owner to convey the 

SI/SD determination. If NFIP-insured buildings 

are substantially damaged by flooding, this letter is 

necessary for owners to file an Increased Cost of Compliance (ICC) claim to help pay to 

bring buildings into compliance (Section 7.6).

n Retain all versions of the Flood Insurance Rate Maps (FIRMs) and allow citizens to access the 

maps. The most recent map, called the “effective” map, is to be used to regulate development, 

including substantial improvements. Earlier versions of the maps are necessary to verify BFE 

data for post-FIRM buildings that pre-date the current effective maps. 

n Maintain in the permit file specific information on all development that occurs within the 

SFHA and make this information available for public inspection. The documentation should 

include the lowest floor elevations, other pertinent elevations such as for machinery and 

equipment, and flood protection designs.

n Conduct periodic field inspections during construction to ensure that development complies 

with issued permits, work with builders and property owners to correct deficiencies and 

violations, and check for unpermitted development.

n Perform assessments after events that cause damage, inform property owners of the 

requirement to obtain permits for repairs, and determine whether the damage qualifies as 

substantial damage.

n Coordinate with property owners and insurance adjusters regarding NFIP flood insurance 

claims and ICC coverage.

5.3	 Property Owner/Applicant Responsibilities

Property owners and applicants for permits have certain responsibilities that are implicit when 

a community adopts regulations and building codes that apply to their properties. First and 

foremost, they have a responsibility to comply with the requirements that are enforced by 

communities, including floodplain management requirements. The following is a summary of 

those responsibilities pertinent to the SI/SD requirements:

n Find out if a permit is required. Most property owners – and all contractors – understand 

that permits are required for some types of work. It is common for owners to specify 

Local building officials have the authority to condemn buildings that 

are judged to be unfit for occupancy. Judging whether to condemn a 

building and making a determination 

of substantial damage are separate 

decisions. A condemned building 

might not be substantially damaged 

and a substantially damaged building might not have conditions that 

warrant condemnation.
SI/SD Desk Reference 5

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

that contractors obtain permits. However, sometimes owners assume that contractors 

automatically do so and, as a result, the work may be undertaken without permits. Legally, 

the responsibility lies with the owner. 

n Submit complete information about all proposed improvements and all repairs to be 

undertaken, including the costs of all work (and valuations of work that the owner or 

volunteers will perform, including estimated costs of donated materials). 

n Share information from insurance claims adjusters, if requested by the local official.

n Provide a professional appraisal of the market value of the building if requested by the local 

official (or accept the market value estimation made by the local official).

n Comply with the approved plans and limitations specified in the issued permit and the 

approved construction documents.

n Inform the local official if new work is to be added to the work already authorized by an 

issued permit. New work must be reviewed to determine whether the community’s floodplain 

management regulations apply. 

n Contact the community to schedule inspections at the appropriate times and submit surveyed 

elevation data when required by the local official.

n Provide “as-built” surveyed elevation data (e.g., FEMA’s Elevation Certificate) to the local 

official to determine compliance (the Elevation Certificate also is necessary for insurance 

agents to determine the appropriate rate for NFIP flood insurance policies). 

n Maintain enclosed areas below elevated buildings as compliant enclosures by not altering any 

aspect required by the permit, including limitations on use for parking of vehicles, building 

access, and storage.

5.4	 Important Community Actions

Communities routinely process permit applications for work on existing buildings. For buildings located in SFHAs, work that constitutes substantial improvement triggers the requirement 

to bring buildings into compliance. Some property owners may view this as an undue burden 

that may cost them considerably more than the work originally proposed. Therefore, it is important that communities have a well-established process that treats all owners in a consistent 

manner. This is especially important in communities that have large numbers of buildings in 

their floodplains that could be damaged by a single event. 

The remaining sections of this chapter will describe the following important community actions 

with respect to SI/SD:

n Informing the public (application forms, websites, handouts)

n Administering the SI/SD requirements

n Exceeding the NFIP minimum floodplain management requirements

n Recommendations to improve flood resistance
5- SI/SD Desk Referenc

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

5.5	 Informing the Public

Most property owners understand that building permits are required when they want to have 

work done on their buildings. However, they are rarely aware of the requirements that apply when buildings are located in SFHAs. Informing the public about the requirements may 

alleviate some of the difficulties that can occur when uninformed owners apply for permits. Successful outreach methods employed by communities include:

n Permit counter staff and inspectors are trained and familiar with the SI/SD requirements 

and other requirements for development in SFHAs and they all convey the same message 

when talking with property owners and contractors.

n Permit application forms or supplements to applications are designed specifically to capture 

information about work proposed for buildings in SFHAs. 

n Handouts at the permit counter explain floodplain requirements, including the SI/SD 

requirements.

n Information is posted online about permit requirements, including SI/SD requirements in 

the SFHA. 

n Newsletters and brochures are used for periodic mailings, such as those described in guidance 

materials developed for the NFIP’s Community Rating System (Section 5.7.1).

5.5.1	 Permit Application Forms

A permit is required for almost every type of development that is proposed in the mapped SFHA. 

Local permit application forms should be designed 

to collect the information needed to make SI/SD determinations. Permit forms should require applicants 

(or their contractors) to provide detailed descriptions 

of the proposed work and detailed breakdowns of the 

costs of work, as this information is essential for making SI/SD determinations. Some communities that have many buildings in their SFHAs 

have developed detailed permit application forms to help them review proposals for work in 

SFHAs, including work on existing buildings. 

Appendix D includes a sample notice called “Sample Notice for Property Owners, Contractors, and Design Professionals” that includes a summary of the “50% rule,” information about 

property valuation, a list of items to be included and excluded in the cost of work, and a costbreakdown sheet. The sample notice includes two affidavits to be signed by the owner and the 

contractor. The affidavits are used to confirm that the work described in an application is all of 

the work that will be done.

5.5.2	 Websites and Handouts

Most communities have websites designed to provide information for their citizens. Websites 

often include sections to explain requirements for various permits and approvals. Some even 

Forms and checklists help ensure 

that all applicants are treated consistently. They also make it easy 

for the local official to document 

SI/SD determinations and to retain 

that documentation in permanent 

records. 
SI/SD Desk Reference 

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

have online permit application capabilities. Increasingly, citizens, designers, and contractors 

are turning to websites to learn about regulations and requirements. Posting information online about development requirements in SFHAs is helpful for communities and their citizens. 

Despite the increased use of the Internet, most communities still provide printed materials. 

Many communities distribute newsletters and brochures to their citizens, including materials 

related to flood hazards, flood insurance, and SFHA construction requirements. 

5.6 	 Administering the SI/SD Requirements

The NFIP requires communities to review all applications for development in SFHAs and to apply their floodplain management regulations and building codes to work that is proposed on 

existing buildings. Chapter 4 described making SI/SD determinations, estimating costs, and estimating market values. This section addresses several topics that local officials encounter when 

administering floodplain management regulations and building codes pertaining to SI/SD: 

n Combinations of types of work

n Phased improvements

n Incremental repair of damaged buildings

n Damaged buildings 

n Special circumstances (involving damaged buildings)

n Appeals of decisions

n Variances to the requirements

n Floodways

n V zones

n Coastal Barrier Resource Areas

n Revisions of the FIRM

n Inspections

n Enforcement and violations

n Recordkeeping

n Issuing SI/SD determination letters

n Rescinding SI/SD determinations

5.6.1	 Combinations of Types of Work

It is common for local officials to see applications for combinations of improvements and repairs. 

In these cases, the combined cost of all work must be used to make the SI/SD determination. 

For example, it is common for property owners who are making necessary repairs to damaged buildings to also include elective improvements. Communities must require applicants to 
5- SI/SD Desk Referenc

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

provide the estimated costs of all proposed improvements and repairs. The total cost is then 

used to make the SI/SD determination, comparing it to the pre-damage or pre-improvement 

market value of the building. Section 6.4 illustrates examples of types of work that local officials 

may see combined in permit applications.

5.6.2	 Phased Improvements

The term “phased improvement” refers to a single improvement that is broken into parts. For a number of 

reasons, owners may wish to schedule anticipated improvements over a period of time, and they may request 

separate permits for each phase. Local officials should 

take care to ensure that phased improvements do not circumvent the substantial improvement requirements. 

Experienced plan reviewers can usually tell if the work described in a permit application adequately identifies all of the work needed to complete the improvement. One approach is to 

remind the applicant that the application is a legal document and that it is the applicant’s 

responsibility (or the responsibility of the applicant’s design professional or contractor) to accurately complete the application. It is also reasonable for the local official to request that the 

applicant state, in writing, that the work proposed is all of the anticipated work and that the 

work can be done for the stated cost estimate. 

Some communities address deliberate phasing of improvements in the permit application or 

other document. Appendix D includes sample affidavits that the community may require be 

signed by owners and contractors to confirm that the work described in an application is all of 

the work that will be done.

Other scenarios of phased improvements include:

n Incomplete work. Permits should not be issued for work that clearly will not result in a 

building that can be occupied without additional work. For example, while a community 

may decide to issue one permit for the foundation, framing, and roof of an addition, and 

a second permit at a later time to complete the remaining work necessary for occupancy 

(electrical, plumbing, flooring, etc.), the SI/SD determination must be made prior to 

issuance of the first permit, and must consider the cost of all work regardless of the number 

of permits issued.

n Multiple permits. Some jurisdictions, especially larger cities and counties, issue separate 

mechanical, electrical, plumbing, and building permits. If handled by different offices, 

coordination is especially important so that the value of all work is combined for the SI/SD 

determination, regardless of the number of permits issued. 

n Consecutive permits. If an application for a second permit is submitted within a short 

period of time after the first permit is issued, the local official should examine whether the 

work covered by the second request is related to improvements to the building. If so, then 

the work must be evaluated in conjunction with the first permit to determine whether the 

combination constitutes substantial improvement. The substantial improvement regulations 

Concern about phased improvements is one reason why some 

communities adopt requirements 

that accumulate the value of improvements over time (Section 

5.7.3). 
SI/SD Desk Reference 

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

apply to all of the work that is proposed as the improvement, even if multiple permits are 

issued. Therefore, the determination of the cost of the improvement should consider all 

costs of all phases of the work before issuance of the first permit. 

n Modification of issued permits. A request to modify an existing permit to add work could 

retroactively trigger substantial improvement. It is common that a permit is issued to 

repair a damaged structure, and the owner subsequently decides to have some additional 

improvements done. Whether the community handles this as a modification of the 

initial permit or issuance of a second permit, care must be taken to reevaluate the SI/SD 

determination. Local officials must verify that the proposed repair work includes all of the 

anticipated work, including improvements to the building.

n Unauthorized work. If unauthorized work on a building in the SFHA is discovered, the 

enforcement action taken by the community must include making an SI/SD determination. 

The costs must include all of the work that has been performed, plus all of the remaining 

work necessary to complete the project.

5.6.3	 Incremental Repair of Damaged Buildings

“Incremental repairs” are similar to phased improvements and refer to a single repair project 

that is broken into parts. When buildings have sustained damage, regardless of the cause, it 

is fairly common for some owners to undertake restoration and repairs over a period of time. 

Sometimes the initial work is only the minimum necessary to make the building safe enough to 

reoccupy (provided reoccupancy is allowed by the community). Sometimes the owner’s financial situation does not allow all of the repairs to be done at the same time.

The definition of “substantial damage” makes it very clear that the substantial damage determination must consider all costs necessary to restore damaged structures to their before-damage 

condition. Even if an owner elects to perform less work or make repairs over time, the community must require the applicant to provide an estimate of the costs to fully restore the structure. 

Section 4.4 includes guidance on estimating the costs of work performed by the owner or volunteers and the costs of donated or discounted materials.

5.6.4	 Damaged Buildings

Most damage occurs during a single and sudden event, 

such as a fire, high wind, lightning strike, falling tree, 

tornado, earthquake, flood, natural gas explosion, etc. 

However, buildings also may be damaged by causes that 

are not related to a specific event. These causes include 

soil settlement, exposure to the elements, termite infestation, vandalism, deterioration over time, and other causes. 

Regardless of the cause of damage, when owners apply for 

permits to repair, communities must determine whether 

the building is substantially damaged. 

Property owners should check their 

insurance policies. Policies that 

include “law and regulations” coverage may cover costs associated 

with complying with requirements 

to bring buildings into compliance 

with flood provisions in local floodplain ordinances or building codes.
5- SI/SD Desk Referenc

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

With respect to making substantial damage determinations, costs to repair must include all costs 

that are necessary to repair a building to its pre-damage condition, even if the owners elect to 

perform only some repairs or incremental repairs (Section 5.6.3).

If a community suffers damage to only a few buildings, 

then the permits for repairs generally can be handled 

under a community’s standard permit processing procedures. Communities that have a large number of buildings 

in their floodplains should decide in advance how best to 

handle inspecting damaged buildings and making substantial damage determinations (Chapter 7). In those circumstances, FEMA’s Substantial Damage 

Estimator (SDE) software provides an effective and efficient approach for developing reasonable 

estimates of the values of buildings and costs to repair or reconstruct buildings (Section 7.5). 

Local officials should become familiar with the ICC coverage that is part of NFIP flood insurance 

policies. ICC claims are only paid on buildings in the SFHA that the local official determines 

to be substantially damaged or that have sustained repetitive flood damage that qualifies under 

the policy. ICC can provide policyholders with up to $30,000 towards costs necessary to bring a

building into compliance with the community’s floodplain management requirements. ICC is 

described in Section 7.6. 

5.6.5	 Special Circumstances (Damaged Buildings)

Communities should be aware of a number of special circumstances that may arise when dealing with damaged buildings:

n Change of ownership. Sometimes owners sell damaged buildings in SFHAs before repairs 

are undertaken. Change of ownership does not have any bearing on the substantial damage 

determination. Regardless of whether the determination is made before or after the sale, it 

is to be based on the value prior to the date of damage. 

n Multiple flood events. Communities may have to address damage resulting from multiple 

flood events. All affected structures should be handled consistently: 

n If no repairs are made to a structure after a flood, and a second flood causes additional 

damage, local officials must include all costs to repair damage from both events. The 

market value of the building used in making an SI/SD determination is the value prior 

to the first flood. If that value cannot be determined, the market value prior to the second flood should be used.

n If some or all repairs are made after a flood (and the cost to repair to the structure was 

determined to not be substantial damage), and a second flood causes damage that must 

be evaluated to determine whether the building was substantially damaged, then the 

market value is the value prior to the second flood. 

n Conditions discovered in the course of doing work. Occasionally, additional damage is 

discovered during the course of work that has been authorized by a permit. For example, 

termite damage or other conditions may not have been identified before the permitted 

work is started, but it is discovered once work is underway. Such conditions may reduce the 

Issuance of an SD determination 

does not necessarily indicate that 

a building is unsafe, unfit for occupancy, or condemned.
SI/SD Desk Reference 5

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

capacity of the load-bearing members or otherwise result in damage to the building. After 

the condition is revealed, if the work that is required to address the discovered condition 

triggers a change in the permit, the community must reevaluate the SI/SD determination. 

The costs of the new work must be added to the cost of the improvement. The market 

value of the building that was used in the original determination is used in the revised 

determination.

5.6.6	 Appeals of Decisions

An applicant for a permit may appeal a decision, order, or determination that was made by the 

local official. This occurs most often if there is ambiguous language in a code or regulations 

that leads to differing interpretations. Typically, appeals are heard by a board designated to hear 

such cases, which may go by a variety of names (board of appeals, board of adjustments, etc.). 

In some small communities, the function may be handled by the jurisdiction’s governing body 

(town council, board of selectmen, etc.).

An owner may appeal the local official’s finding or determination that the proposed work constitutes SI/SD. The owner may appeal an SI/SD determination on the basis of insufficient 

information, errors, repair/improvement costs that should be included/excluded, inappropriate valuations of costs for the proposed work, or an inappropriate method to determine the 

market value of the building.

It is not appropriate for an owner who wishes to build in a manner that is contrary to the regulations and codes to seek an appeal. In those cases, the owner would seek a variance. 

5.6.7	 Variances to the Requirements

A variance is a grant of relief from the terms of a land use, zoning, or building code regulation. 

If granted, it allows construction in a manner that is otherwise prohibited. The burden of determining whether to grant a variance rests on the community.

The primary goals of the NFIP and local floodplain management regulations and codes are the reduction of 

damage and protection of public health and safety. Because a variance from the requirements for construction 

in SFHAs can create an increased risk to life and property, local officials should carefully consider requests for 

variances from flood elevation or other floodplain management requirements.

The NFIP regulations do not set forth absolute criteria 

for granting variances [44 CFR § 60.6]. The regulations 

outline procedures that communities must follow (see FEMA 480, Floodplain Management Requirements: A Study Guide and Desk Reference for Local Officials for additional guidance on handling 

variances). Variances shall only be issued based on the following:

n A showing of good and sufficient cause;

NFIP flood insurance policies on 

post-FIRM buildings and substantially improved buildings that do 

not comply with the NFIP requirements, even if authorized by a 

properly issued variance, are rated 

according to risk. The cost will be 

high if a variance allows the lowest floor to be below the BFE (see 

Figure 6-14 in Section 6.6).
5-10 SI/SD Desk Referen

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

n A determination that failure to grant the variance 

would result in exceptional hardship (consistent with 

usage related to land use and zoning, in this context a 

“hardship” must be related to the land, not a financial 

or personal circumstance of the owner); 

n A determination that granting the variance will not 

result in increased flood heights, additional threats 

to public safety, extraordinary public expense, create 

nuisances, cause fraud on or victimization of the public, 

or conflict with existing local laws or regulations; and

n Evidence that the variance is the minimum necessary 

to afford relief, considering the flood hazard.

As a guiding principle, a variance should pertain to the 

unique characteristics of the land itself. A properly issued 

variance may be granted for a parcel of land with physical 

characteristics so unusual that complying with the regulation or code would create an exceptional hardship for 

the applicant. However, a variance should not be granted 

based on the personal circumstances of an individual. 

Sometimes variances are sought because the owner or the designer believes they will not be 

able to meet the community’s floodplain management regulations. Usually there are alternative 

ways to comply that would negate any purported justification for a variance, and local officials 

should require consideration of those alternatives before acting on variance requests. Typical 

characteristics of a parcel of land that might justify a variance include an irregularly shaped lot, 

a parcel with unsuitable soils, or a parcel with an unusual geologic condition below ground level. However, it is unusual that any physical characteristic would give rise to a hardship that would 

be sufficient to justify issuing a variance to the elevation requirement. 

A community that grants a variance based on the above evidence and according to FEMA guidance does not jeopardize its standing in the NFIP. However, FEMA and the States periodically 

evaluate how effectively communities administer their floodplain management requirements. 

FEMA becomes concerned when there is a pattern of variances that suggest the practice is used 

to circumvent requirements.

Communities that administer the I-Codes may handle variances to the flood provisions through 

their boards of appeals. Unless the State or community has modified or replaced the administrative provisions, the IRC specifies that the building official will review information provided 

with permit applications for work on buildings in SFHAs. The official will make a finding based 

on the cost of the proposed work and the market value of the building and, if the results indicate the work is a substantial improvement, the finding is forwarded to the board of appeals 

for a final determination. Communities have a board of appeals (which might go by another 

name) to hear and decide appeals of orders, decisions, or determinations made by the building 

official. The IRC outlines specific responsibilities of the board when hearing matters related to 

Insufficient justifications for variances to the SI/SD requirements 

include:

n Inconvenient access to an addition

n Difficult access for those with 

physical limitations

n Too costly to comply

n The owner does not plan to 

get flood insurance

n Building will look different

n Building will need a waiver of 

height limitations
SI/SD Desk Reference 

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

structures in SFHAs, including: 

n Determination of substantial improvement in areas prone to flooding. Requires the board 

of appeals to evaluate the building official’s finding regarding the value of proposed 

improvements to determine if the work constitutes SI/SD.

n Criteria for issuance of a variance for areas prone to flooding. Sets forth specific criteria, 

consistent with the minimum NFIP requirements, to be applied in the review and 

consideration of variances to the minimum flood hazard area requirements.

5.6.8	 Floodways

Local officials must examine proposals for work on buildings that are located in floodways to determine whether 

the work constitutes SI/SD. If a building is located in a 

floodway, bringing it into compliance may involve a floodway encroachment analysis. The NFIP regulations require 

that this analysis be performed for any work that encroaches into a floodway [44 CFR § 60.3(d)(3)]. If the analysi

indicates any increase in the BFE, the local official must 

not allow the proposed work.

The analysis that is performed to delineate floodways 

takes into consideration existing encroachments and obstructions (including buildings) that were present at the 

time the data were collected for the analysis. This means that proposals for work on existing 

buildings that are located in a floodway are evaluated based on whether the exterior dimensions 

(footprint) of the original buildings will be increased, as follows:

n No change to footprint. Substantial improvement that does not expand the footprint might 

be an interior-only renovation or an added story. If the actions necessary to bring the building 

into compliance do not increase the exterior dimensions, a floodway encroachment analysis 

is not required. Note that enclosing a deck that is below the BFE to change it to livable space 

should be treated as an addition even though the work does not increase the footprint; the 

addition becomes an encroachment in the floodway and an analysis must be prepared. 

n Increase in footprint, substantial improvement. If work that increases the footprint (including 

an increase in fill, if used for elevation) involves an addition (or a combination of interior 

work and an addition) is determined to be a substantial improvement, the building must be 

brought into compliance. In this case, a floodway encroachment analysis is required because 

the exterior dimensions will be increased. A permit for the increase in footprint cannot be 

issued if the analysis indicates any increase in the BFE. An option that may decrease the 

effects of encroachment is to elevate additions on open foundations (piers or columns).

n Increase in footprint, non-substantial improvement. Local officials must review all proposed 

development in SFHAs and authorize the development by issuing permits. Development 

includes additions that do not constitute substantial improvements. If located in a floodway, 

a proposal to expand the exterior dimensions of a building with an addition that is not 

The NFIP defines the floodway as 

the channel or other watercourse 

and the adjacent land areas that 

must be reserved in order to discharge the base flood without 

cumulatively increasing the water surface elevation more than a 

designated height. Floodways are 

delineated along most waterways 

that are studied using detailed 

methods.
5-12 SI/SD Desk Refere

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

a substantial improvement must be supported with a floodway encroachment analysis. 

Although the NFIP regulations do not require that the addition be elevated and meet all 

other requirements of the NFIP, the addition may be a potential encroachment into the 

floodway that must be evaluated. If the floodway analysis indicates any increase in the BFE, 

a permit cannot be issued for the addition. 

5.6.9	 V Zones

Local officials must review proposals to improve structures that are located in V zones to determine compliance 

with the NFIP’s V zone provisions, as well as the requirements for substantial improvements found in 44 CFR 

§ 60.3(e). In V zones, new and substantially improved

buildings must:

n Be elevated on open foundations (pilings or columns) 

that allow floodwaters and waves to pass beneath the 

elevated buildings

n Be elevated so that the bottom of the lowest horizontal 

structural member of the lowest floor is at or above 

the BFE

n Have the foundation anchored to resist flotation, collapse, and lateral movement due to the 

effects of wind and water loads acting simultaneously on all building components

n Have the area beneath the elevated building free of obstructions that would prevent the free 

flow of floodwaters and waves during a base flood event 

n Have utilities and building service equipment elevated above the BFE

n Have the walls of enclosures below the elevated building designed to break away under base 

flood conditions without transferring loads to the foundation

Section 6.4 describes some of the more common examples of improvements and repairs and descriptions of how 

property owners and contractors can meet NFIP requirements (also see Tables 6-1a and 6-1b). It is important t

note again that work on a post-FIRM building cannot be 

allowed if it would make the building non-compliant with 

the floodplain management requirements that had to be 

met when the building was constructed. 

5.6.10	 Coastal Barrier Resource Are

The Coastal Barrier Resources Act of 1982, and later amendments, prohibits the NFIP fr

providing flood insurance for structures built or substantially improved after October 1,

1983, in any areas designated as undeveloped coastal barriers. These areas are mapped a

designated by Congress as units of the Coastal Barrier Resource System (CBRS) and are shown 

In V zones, a registered professional engineer or architect shall 

develop or review the structural design, specifications, and plans and 

shall certify that the design and 

methods of construction are in accordance with accepted standards 

of practice to meet the V-zone 

requirements. 

All substantially improved buildings in V zones must be elevated. 

Floodproofing is not allowed in V 

zones, even for non-residential 

buildings.
SI/SD Desk Reference 

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

on FIRMs. The FIRMs also show areas designated as Otherwise Protected Areas (OPAs), which include portions 

of coastal barriers that are used primarily for natural resources protection and are owned by Federal, State, and 

local governments or by certain non-profit organizations.

Local officials must process permit applications for repairs and improvements to buildings in CBRSs and OPAs. 

If the work is SI/SD, then it must comply with the minimum requirements of the NFIP. It is important to realize 

that pre-FIRM buildings in CBRSs and OPAs that qualified 

for NFIP flood insurance may lose that eligibility if they are substantially improved or sustain 

substantial damage. Federal flood insurance may be obtained for a structure in the OPA if written documentation certifies that the structure is used in a manner consistent with the purpose 

for which the area is protected.

5.6.11	 Revisions of the FI

In many communities, flood hazard maps have been revised to reflect new floodplain studies, better flood data, 

improved topographic data, new encroachments and 

bridges, and for other reasons. When flood hazard maps 

are revised, either the SFHAs expand in area and the 

BFEs increase, or the SFHAs reduce in area and the BFEs 

decrease. Map revisions may reflect changes in community boundaries, zone designation, new floodway delineations, or changes in floodway boundaries. 

Also, A zones without BFEs may be studied and shown with BFEs, or waterways that were previously unmapped may be shown with SFHAs.

Communities must maintain all versions of their Flood Insurance Studies (FISs) and flood 

hazard maps. This is an important responsibility because it affects consideration of work on 

buildings constructed in compliance with a map that pre-dates a current effective map. Section 

6.4.8 describes repairs and improvements on post-FIRM buildings where there have been revisions to the FIRM.

5.6.12	 Inspectio

Even when building permits and construction plans are complete, proper inspections during 

construction are important to determine whether any work has deviated from the approved 

permits and plans. Building inspectors need to understand the flood damage-resistant design 

and construction requirements that they are to check during inspections. If deviations from the 

conditions of a permit or plans are discovered early during construction, it will be easier to work 

with the owner and builder to achieve compliance through corrective actions. 

Using a plan review and inspection checklist can make inspections easier because the inspector has a standardized summary of floodplain management requirements. A checklist also 

Permits are required for new construction and for improvements of 

existing buildings in CBRSs and 

OPAs. Communities are required to 

administer their floodplain management regulations even if Federal 

flood insurance is not available for 

new buildings and substantially improved buildings in these areas. 

The NFIP expects communities to 

maintain copies of all flood hazard 

maps, even those that have been 

replaced with revised maps. This is 

especially important when work is 

proposed on post-FIRM buildings. 
5-14 SI/SD Desk Referen

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

documents the inspection, which can be important if 

questions arise regarding compliance. 

The following inspections are recommended for buildings that are required to be brought into compliance with 

the floodplain management requirements for new construction and substantial improvements: 

n Footing or Foundation Inspection. Buildings and 

additions that are elevated on solid perimeter 

foundation walls create enclosures below the elevated 

buildings (e.g., crawlspace or underfloor space). 

Inspectors should check for the specified number, size, 

and location of flood openings. The bottom of each 

flood opening must be no higher than  foot above finished exterior grade or interior floor;

flood openings should not be confused with underfloor air ventilation openings, which are 

located just under the floor level. For slab-on-grade (and stemwall) foundations, the lowest 

floor inspection is also conducted at this time.

n Lowest Floor Inspection. The best time to verify compliance with the elevation requirement 

is after the lowest floor elevation is set, but before further vertical construction takes place. 

An error in elevation of a foot or two may seem minor, but corrective action can be expensive 

and complicated if that error is discovered after the walls and roof are in place.

n HVAC Inspection. Verify that utilities and mechanical equipment are elevated or designed 

to prevent water from entering or accumulating within the components during conditions 

of flooding [44 CFR § 60.3(a)(3)]. Frequently overlooked items include heating, ventilation

and cooling equipment; electrical outlets; plumbing fixtures; and ductwork that is installed 

under the floor, usually in a crawlspace.

n Enclosure Inspection. Inspect enclosures below elevated buildings to ensure that they comply 

with the limitations on use (parking, building access, or storage), protection of HVAC 

described above, the use of flood damage-resistant materials, and the specific requirements 

based on the flood zone (openings in A zones or breakaway walls in V zones).

n Final Inspection. A final inspection to document compliance can be performed at the same 

time as the final inspection to issue the occupancy certificate. During final inspections:

n Collect the “as-built” documentation of elevations prior to the final sign-off and issuance 

of occupancy certificates.

n If used, complete and sign the plan review and inspection checklist and place all inspection reports in the permit file.

5.6.13	 Enforcement and Violatio

Proper enforcement of the floodplain management provisions is a critical part of fulfilling a 

community’s responsibility under the NFIP. During construction, violations of the provisions 

must be resolved as soon as they are discovered and before further construction takes place. 

What may first appear to be a minor violation could turn out to be a significant issue that not 

The NFIP requires communities 

to obtain and retain documentation of the lowest floor elevations of 

new buildings and substantially improved buildings. FEMA’s Elevation 

Certificate is designed specifically 

for this purpose. 

FEMA’s Floodproofing Certificate

is designed to satisfy the documentation requirements when non-residential buildings are proposed to 

be dry floodproofed.
SI/SD Desk Reference 5

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

only exposes property owners and occupants to future 

flood damage, but results in higher NFIP flood insurance 

policies. 

If the community has exhausted legal means to remedy a 

violation and the owner refuses to resolve the matter and 

bring the building into compliance, the community may 

cite the structure as a violation in accordance with Sec. 

1316 of the National Flood Insurance Act of 1968. 

provision allows the NFIP to deny flood insurance on the building that remains in violation, and 

on all other insurable buildings on the property. Owners who refuse to resolve violations should 

be informed that denial of flood insurance can have significant consequences: the property may 

be difficult to sell; the owner may have problems with the mortgage lenders if flood insurance 

cannot be maintained; and future Federal disaster assistance may be denied. 

A community’s standing in the NFIP depends on making a good faith effort to successfully resolve violations. By allowing a violation to go unresolved, the community may set a precedent, 

making it more difficult to take future enforcement actions and potentially jeopardize participation in the NFIP.

5.6.14	 Recordkeepi

Obtaining certain documentation and maintaining complete permit records are key responsibilities for communities that participate in the NFIP. Certifications or documentation of the 

following must be maintained for all new buildings constructed in SFHAs and, if applicable, for 

buildings that are substantially improved:

n The permit application form and all attachments, including the site plan

n Documentation of the SI/SD determination

n Community letter documenting the SI/SD determination (Section 5.6.15

n Floodway encroachment analyses (Section 5.6.8)

n Records of inspections of the project while under construction such as obtaining the lowest 

floor elevations, which is initially obtained after the foundation is in place but prior to 

further vertical construction, and other pertinent elevations 

n Design of engineered openings that are used as alternatives to the prescriptive openings in 

the walls of enclosures below elevated buildings in A zones (see FEMA Technical Bulletin 

1, Openings in Foundation Walls and Walls of Enclosures Below Elevated Buildings in Special Flood

Hazard Areas)

n In coastal high hazard areas, engineering certifications of designs and construction methods 

of new and substantially improved buildings (5.6.9

n Designs for breakaway walls around enclosures below elevated buildings in V zones if 

prescriptive solutions are not used (see FEMA Technical Bulletin 9, Design and Construction

Guidance for Breakaway Walls Below Elevated Buildings Located in Coastal High Hazard Areas)

The NFIP expects communities to 

attempt all reasonable actions to 

bring violations into compliance. 

When such attempts are unsuccessful, the community should 

contact the NFIP State Coordinator 

or the FEMA Regional Office for 

advice. 
5-16 SI/SD Desk Referen

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

n Evidence that work proposed for listed historic structures will not preclude continued listing 

(Section 6.5.1

n Variance proceedings, including justifications and notifications to recipients (Section 

5.6.7)

n Record of final inspections of the construction project before the certificate of occupancy is 

issued, such as location and size of openings, location of utilities, and “as-built” lowest floor 

elevation

n Certification of the elevation to which any nonresidential building has been floodproofed 

before the certificate of occupancy is issued

Although the use of checklists is not required by the NFIP, it is a good way to document plan 

reviews, inspections, and compliance. Some communities use checklists during plan reviews 

to verify that appropriate flood damage-resistant provisions have been checked and found to 

satisfy the applicable requirements. Similarly, the use of inspection checklists improves the consistency of inspections and helps verify the flood damage-resistant requirements.

5.6.15	 Issuing SI/SD Determination Lette

Local officials should convey SI/SD determinations to 

property owners in an official letter. Because this letter 

notifies the owners of a significant requirement, it is recommended that it be sent in a manner that documents 

receipt by the addressee. Appendix E includes three 

sample letters to send SI/SD determinations to property 

owners. One sample is used to notify owners when a local official determines that proposed improvements are 

substantial improvements. Another sample is used to notify owners when a local official determines that buildings 

have sustained substantial damage. The third sample is 

used to notify owners that it has been determined that damage does not constitute substantial 

damage. The local official should offer to meet with owners or representatives to explain the 

various aspects required for buildings to meet the community’s floodplain management regulations for new buildings, explained in Chapter 6.

5.6.16	 Rescinding SI/SD Determinatio

Local officials use data to make findings and determinations regarding whether work constitutes substantial improvement or repair of substantial damage. The data, described in detail in 

Chapter 4, consist of the cost estimates of the proposed improvements or the cost estimates of 

work that is required to repair damaged buildings to their pre-damage condition, regardless of 

the amount of work that will be done. The data also include the market values of buildings prior 

to the improvement or before the damage occurred. 

If substantial damage is caused 

by flooding and the buildings are 

insured by the NFIP, then the SD 

determination letter is necessary 

for owners to file ICC claims under 

NFIP flood insurance policies to 

help pay to bring the buildings into 

compliance with the community’s 

floodplain management requirements (Sections 5.6.4 and 7.6).
SI/SD Desk Reference 5

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

Determinations usually are based on data provided by the owner, the owner’s representative, 

or a contractor. Other sources of repair costs and improvement costs and market value are described in Chapter 4.

Following receipt of an SI/SD determination, property owners may appeal the determination 

(Section 5.6.6) or may submit new data and request that the initial determination be rescinded. 

When new data are provided, local officials should evaluate it carefully. Rescinding a determination means the owner’s investment in a flood-prone area would take place in a manner that 

continues the exposure of the existing structure and the investment to flood damage. Communities should thoroughly document and retain evidence of any appeals and changes to SI/SD 

determinations in their permanent records. 

5.7	 Exceeding NFIP Minimum Requirements

Some States and communities have adopted requirements 

for SI/SD that exceed the NFIP minimum requirements 

to better protect their citizens and property. The NFIP 

encourages communities to evaluate their own situations, 

degree of flood risk, and vulnerability of their residential 

and commercial properties, and to consider adopting requirements that are more restrictive in order to achieve 

the long-term goal of being more resistant to flood disasters. The more restrictive provisions take precedence. 

Many communities adopt higher standards in order to 

qualify for credit under the NFIP’s Community Rating 

System (CRS). Section 5.7.1 is an overview of the CRS,

a voluntary program that provides discounts on Federal 

flood insurance rates.

In terms of higher standards that relate to SI/SD, the two 

approaches that exceed the NFIP minimums are:

n Lower threshold for SI/SD (Section 5.7.2

n Cumulative SI/SD (Section 5.7.3

5.7.1	 Community Rating System

The NFIP established the Community Rating System to encourage activities that exceed the 

NFIP minimum requirements and are effective at reducing flood damage and claims under the 

NFIP. In communities that apply to the CRS and are verified as implementing certain activities, 

citizens who purchase Federal flood insurance benefit from discounts on premiums ranging 

from 5 percent to as much as 45 percent.

For more than 40 years, communities that participate in the NFIP have recognized flood hazards in their construction and development decisions. Until 1990, the NFIP had few incentiv

In 2003, the Association of State 

Floodplain Managers, Inc. (ASFPM) 

reported that several States have 

requirements that exceed the NFIP 

minimum requirements for substantial improvement. In these 

cases, State requirements take 

precedence. 

The CRS has three goals: 

1. Reduce flood losses

2. Facilitate accurate insurance 

rating

3. Promote awareness of flood 

insurance
5-18 SI/SD Desk Referen

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

for communities to do more than administer the minimum NFIP regulatory provisions. During 

those early years, flood insurance rates were the same in every community, even though some 

elected to exceed the minimum provisions.

The CRS is a voluntary program. Any community that 

is in full compliance with the regulations of the NFIP is 

considered to be in “good standing” and may apply for a 

CRS classification. A community’s CRS classification is a 

ranking based on the credit points calculated for specific 

floodplain management activities undertaken to meet the 

goals of the NFIP and the CRS. There are 18 creditable

activities organized under 4 categories. One category includes more restrictive requirements for work on existing 

buildings. 

The discount on NFIP flood insurance premiums is only 

one incentive for communities to undertake activities 

credited by the CRS. The larger benefits are improved 

public safety, reduced damage to property and public infrastructure, avoidance of economic disruption and losses, 

reduction of human suffering, and protection of the environment.

Additional information about the CRS can be found through the appropriate NFIP State Coordinator, the appropriate FEMA Regional Office, by downloading the Coordinator’s Manual at the 

CRS Resource Center (http://training.fema.gov/EMIWeb/CRS), or by checking the NFIP CRS 

section of FEMA’s website at http://www.fema.gov/business/nfip/crs.shtm. 

5.7.2	 Lower Threshold for SI/SD

The NFIP’s threshold for determining whether proposed work constitutes substantial improvement, or repair of substantial damage, is 50 percent. Compliance is required when the costs of 

an improvement or the costs to repair damage equal or exceed 50 percent of a structure’s market value. 

Adopting a lower threshold, such as 40 percent or 30 percent, is perhaps the easiest way to exceed the NFIP minimum requirement. The concept is simple – compliance is required when

the ratio of costs compared to market value equals or exceeds the lower percentage specified in 

the community’s regulations. Communities should make certain that they uniformly apply the 

lower threshold to all buildings in SFHAs, even after events that cause damage to many buildings, regardless of the cause of the damage. 

Additional guidance for regulatory language and implementation of a lower threshold for SI/

SD is found in CRS Credit for Higher Regulatory Standards, which is accessible online (http:// www.

fema.gov/library/viewRecord.do?id=2411

CRS credits are available to communities that adopt more restrictive 

SI/SD requirements:

n 43 CRS communities get credit 

for a lower threshold for SI/SD

n 289 CRS communities get credit for cumulative SI/SD

(Data as of October 2009)

The CRS offers credits to communities that adopt more restrictive 

requirements for SI/SD.
SI/SD Desk Reference 

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

5.7.3	 Cumulative SI/SD

Many pre-FIRM buildings are subject to repetitive flood damage. Because of the nature of many 

flood hazard areas where repetitive flooding occurs, many of the buildings in these areas are 

unlikely to sustain the level of damage that qualifies as substantial damage based on the NFIP 

minimum 50 percent trigger. One way that communities can achieve long-term reduction of 

flood losses is to adopt a requirement that all improvements and repairs are tracked over time 

and counted towards the SI/SD determination. Another reason some communities take this approach is to capture “phased improvements,” described in Section 5.6.2.

Adopting what is usually referred to as a “cumulative substantial improvement” requirement 

means that buildings will be brought into compliance with flood damage-resistant standards 

sooner than if the community administers the minimum NFIP requirement, which applies to 

each separate application for improvements and repairs. 

The following change to the definition of “substantial improvement” is an example of how 

a cumulative substantial improvement requirement can be implemented (suggested new text 

is underlined). A more limited approach would be to count only repairs of damage (not improvements) in a cumulative manner. Communities should carefully consider the period of 

time to specify, whether the “life of the structure” or a specific period of time, such as 5-, 15-, or

30-years.

“Substantial improvement” means any combination of repairs, reconstruction, rehabilitation, addition, or other improvement of a structure taking place during [insert period of time selected by the 

community] the cost of which equals or exceeds fifty percent of the market value of the structure before 

the work is started. This term includes structures that have incurred ’substantial damage,’ regardless of the actual repair work performed.

A good system for recording and accessing records is necessary to administer a cumulative SI/

SD requirement. Each time an owner applies for a permit to make improvements or repairs, the 

records for that building must be checked. Obviously, this is feasible only if those records are 

retained over the period of time specified in the regulations. 

Tracking the cost of repairs and improvements over time is straightforward but, for the purpose 

of making SI/SD determinations, the community must have a market value to compare to those 

costs. Because the market value of a building changes over time, communities need to decide 

how they will handle those changes. One approach is to obtain the market value each time a 

permit is obtained, use it in the computation each time, and add the resulting percentages. 

Communities may choose to accumulate percentages or repair/improvement costs over a set 

period of years. Table 5-1a illustrates this approach where market value increases steadily, and

Table 5-1b illustrates this approach where the market value first decreases and then increases.
5-20 SI/SD Desk Referen

5 ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS

Table 5-1a. Tracking Cumulative Substantial Improvements, Determining Market Value for Each Permit Application

(shows increases in market value).*

Elapsed time

from initial permit

application

Current market

value

(at the time of each 

permit application)

Cost of

improvement

Cost as percentage

of current

market value

Cumulative

percentage

0 year $100,000 $10,000 10% 10%

3 years $110,000 $42,000 38% 48%

6 years $120,000 $10,000 8% 56%

* In this example, the 50 percent threshold is reached with the third permit application.

Table 5-1b. Tracking Cumulative Substantial Improvements, Determining Market Value for Each Permit Application

(shows decrease, then increase in market value).*

Elapsed time

from initial permit

application

Current market

value

(at the time of each 

permit application)

Cost of

improvement

Cost as percentage

of current

market value

Cumulative

percentage

0 year $100,000 $10,000 10% 10%

3 years $90,000 $28,000 31% 41%

6 years $105,000 $10,800 10% 51%

* In this example, the 50 percent threshold is reached with the third permit application.

Communities will only have records of work for which permits are required. Owners may undertake work that does not require a permit (e.g., patching a roof or replacing a window) and 

those costs would not count towards the cumulative substantial improvement. It is not the intent of a cumulative substantial improvement requirement to discourage general maintenance 

and upkeep. However, if any part of the work requires a permit, then all of the proposed work 

is counted in the SI/SD determination. For example, as part of a project to repair roof damage 

that involves replacing rafters and underlayment, the owner may decide to replace shingles on 

an undamaged portion of the roof. The cost of the re-shingling is included in the determination.

Additional guidance for regulatory language and implementation of a cumulative substantial 

improvement requirement is found in CRS Credit for Higher Regulatory Standards.

5.8	 Recommendations to Improve Flood Resistance

Local officials can encourage owners to improve the flood resistance of older buildings during 

the course of repairs and improvements even if owners propose improvements or repairs that 

do not trigger the SI/SD requirements. Improving resistance can facilitate rapid clean-up and 

recovery, and reduce repair costs. Whether these actions are applicable to a specific situation 

depends, in part, on the characteristics of the flood hazard and the building:
SI/SD Desk Reference 

ADMINISTERING SUBSTANTIAL IMPROVEMENT AND SUBSTANTIAL DAMAGE REQUIREMENTS 5

n Replace gypsum board or wood paneling below the BFE (preferably below the BFE plus 

foot or more) with vinyl panels that can be removed to facilitate clean-up and drying before 

being reinstalled.

n Replace insulation with closed-cell foam insulation that can be cleaned, dried, and 

replaced.

n Replace flooring and floor finishes with flood damage-resistant materials.

n Relocate mechanical equipment out of basements or other flood-prone spaces and elevate 

above the BFE.

n Abandon the use of below-grade areas (basements) and fill them in to prevent structural 

damage.

n Install flood openings in crawlspace foundation walls and garage walls (see FEMA Technical 

Bulletin 1, Openings in Foundation Walls and Walls of Enclosures Below Elevated Buildings in

Special Flood Hazard Areas).

n Install backflow devices in sewer lines.

n If sufficient warning time is available from official sources, pre-plan actions to move contents 

from the lower floors to the higher floors when a warning is issued.

SI/SD Desk Reference 6

6	 Factors to Consider and

Illustrations of Substantial

Improvement and Repair of

Substantial Damage

6.1	 Overview

This chapter describes the factors to be considered when evaluating permit applications for improvements and repairs to buildings and includes, in Section 6.4, illustrations of several types 

of improvements and repairs that could trigger SI/SD determinations. Section 6.3 describes all 

aspects of the NFIP floodplain management requirements that must be considered when bringing SI/SD buildings into compliance. Section 6.5 describes how certain types of buildings are 

addressed, including historic structures, manufactured homes, accessory structures, and certain 

agricultural structures. And finally, Section 6.6 explains the NFIP flood insurance implications 

related to SI/SD.

6.2	 Factors to Consider When Evaluating Permit Applications for

Improvements and Repairs

Several factors must be considered when local officials 

evaluate permit applications for repairs and improvements to buildings: 

n Whether the building is pre-FIRM or post-FIRM 

(Section 6.2.1)

n Whether the building is in an A zone or a V zone 

(Section 6.2.2).

n Whether the building is located in more than one 

flood zone (Section 6.2.3). 

n Whether the building is residential or non-residential (Section 6.2.4).

n The nature of the proposed repairs and improvements; Section 6.4 illustrates examples of 

various types of improvements and repairs and how they must meet NFIP requirements. 

6.2.1	 Pre-FIRM or Post-FIRM

This chapter presents some examples of common improvements and repairs, along with descriptions of measures to comply with the NFIP floodplain management requirements. For purposes 

It is important to emphasize that all 

work must be included in an SI/SD 

determination. For example, if a 

small addition by itself is not a substantial improvement, but if other 

work on the building is undertaken at the same time, the combined 

work might be a substantial improvement (see Section 5.6.1).
6- SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

of explaining these examples, this Desk Reference uses the terms “pre-FIRM” and “post-FIRM,” 

which are described below. 

Buildings that were constructed before the date of a community’s flood hazard map are called 

“pre-FIRM” because they pre-date the initial FIRM. They are referred to as “existing construction” or existing buildings. They generally pre-date the date of the community’s first floodplain 

management regulations. Most flood-prone, pre-FIRM buildings were built by individuals who 

did not have sufficient knowledge of the hazard to make informed decisions about the flood 

risk. Thus, most pre-FIRM buildings were not built with specific measures that reduce exposure 

to flooding, such as elevating the floor a certain height above the flood level. 

Buildings that were constructed after the date of the initial FIRM are called “post-FIRM.” These 

buildings were generally constructed after adoption of the community’s first floodplain management regulations and thus should have been built in compliance with the NFIP floodplain 

management requirements that were in effect at the time of construction.

A building constructed after the date of the initial FIRM 

is considered new construction (see definition in Chapter 

3). All new construction must be built in accordance with 

the NFIP requirements. Regardless of the size or costs of 

improvements or repairs made to post-FIRM buildings, 

the building must remain fully compliant.

In summary, how proposals to make improvements or repairs must be evaluated as a function of whether buildings 

are pre-FIRM or post-FIRM is as follows:

n If a building is pre-FIRM, any proposed improvements or repairs must be evaluated to 

determine whether the work is a substantial improvement or repair of substantial damage. 

n If a building is post-FIRM, any proposed improvements or repairs must be evaluated to ensure 

that the improvements or repairs comply with the applicable NFIP floodplain management 

requirements and to ensure that the improvements or repairs do not alter any aspect of the 

building that would make it non-compliant.

6.2.2	 A Zone or V Zone

The term “A zone” includes all zones shown on FIRMs as Zones A, AE, A1-A30, AR, AO, A99,

and AH. A zones are shown along riverine bodies of water and along tidally-influenced bodies 

of water, typically inland of V zones. V zones are flood hazard areas with high velocity wave action where wave heights of 3 feet or more are anticipated. The term “V zone” includes all zones 

shown on FIRMs as Zones V, VE, and V1-V30. The basic NFIP floodplain management requirements for the design and construction of buildings in A zones and V zones differ somewhat.

Some of the key differences are:

n A zone: the lowest floor, including basement, is elevated to or above the BFE.

n V zone: the bottom of the lowest horizontal structural member of the lowest floor is elevated 

to or above the BFE.

All subsequent work on a postFIRM building must be performed 

in a manner that ensures the building’s continued compliance. Work 

shall not be allowed if it would make 

the building non-compliant with the 

floodplain management requirements that had to be met when the 

building was constructed.
SI/SD Desk Reference 

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

n A zone: enclosures below elevated buildings must have flood openings. 

n V zone: the areas below elevated buildings are either free-of-obstructions or enclosed with 

insect screening, latticework, or breakaway walls. 

n A zone: non-residential buildings may be dry floodproofed.

n V zone: dry floodproofing is not allowed for non-residential buildings.

n V zone: new buildings must be located landward of the reach of the mean high tide. 

6.2.3	 More Than One Flood Zone

Buildings that are located in more than one zone must comply with the requirements of the 

more restrictive zone. For example, a building that is a substantial improvement that is in both 

a V zone and an A zone must be designed and constructed to meet the V zone requirements. In 

riverine A zones, similar situations may occur. A building that is affected by more than one BFE 

must be elevated to the higher BFE, and a floodway analysis is required even if only a portion of 

a building encroaches into the floodway.

6.2.4	 Residential or Non-Residential

As noted in Section 6.2.2, the requirements for non-residential buildings vary depending on 

flood zone. In A zones, non-residential buildings may be elevated or dry floodproofed. Section 

6.4.1 describes dry floodproofing as a possible method of protecting non-residential buildings

in A zones that are substantially improved or substantially damaged. In V zones, substantiallyimproved non-residential buildings must have the bottom of the lowest horizontal structural 

member of the lowest floor elevated to or above the BFE.

6.3	 Bringing Substantially Improved and Substantially Damaged

Buildings into Compliance

If a local official determines that improvements or repairs 

to a building constitute SI/SD, then the building must be 

brought into compliance with the NFIP floodplain management requirements for new construction in SFHAs.

The key aspects of the NFIP requirements for new construction and SI/SD include: 

n Lowest floor elevations (Section 6.3.1

n Enclosures (Section 6.3.2)

n Basements (Section 6.3.3)

n Utility and building service equipment (Section 6.3.4)

n Flood damage-resistant materials (Section 6.3.5)

n Making buildings reasonably safe from flooding (Section 6.3.6)

For several reasons, owners may 

decide to demolish existing buildings. If a property owner chooses 

to construct a new building on the 

same site, the work is treated as 

new construction and all requirements for new construction must 

be met.
6- SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

The sections below describe these requirements. The examples given below each NFIP requirement describe measures that can be used to bring SI/SD buildings into compliance. These 

examples are not an exhaustive list of possible ways to meet the NFIP requirements.

6.3.1	 Lowest Floor Elevations

For SI/SD buildings that have lowest floors below the BFE, 

the lowest floor must be elevated to bring the buildings 

into compliance. In A zones, the lowest floor must be at 

or above the BFE (non-residential buildings may be dry 

floodproofed to or above the BFE), and in V zones, the 

bottom of the lowest horizontal structural member of the 

lowest floor must be at or above the BFE. 

There are several solutions that can achieve compliance. 

The solution selected for any given building will depend on several factors such as flood zone, 

the type of foundation, feasibility, and whether the building is residential or non-residential.

Below are examples of measures that can be taken to meet NFIP requirement to bring SI/SD 

buildings into compliance:

n Elevation-in-place (A and V zones). This measure 

involves detaching the building from its foundation 

and raising it onto a compliant foundation. Elevationin-place is most effective for buildings that are on 

crawlspaces, pilings, or columns. Buildings with 

basements also may be elevated (see Section 6.3.3 

for measures to bring basements into compliance). 

Slab-on-grade buildings have been elevated-in-place, 

although the process is more complicated and 

costly (these buildings may be better candidates for 

conversion of the ground level to become a compliant 

enclosure, described below).

n Conversion of the ground level to a compliant enclosure (typically in A zones). There are 

instances, typically in A zones, where the first (ground) floor is subject to flooding, but the 

next higher floor is above the BFE. In these cases, it may be feasible to modify the ground 

level so that it becomes an enclosure that complies with the NFIP requirements. (This 

option is unlikely to be applied in V zones because the vertical structural members (piers, 

pilings, or columns) of older buildings rarely extend high enough.) This option requires 

that the structure meet all applicable NFIP requirements, including limitations on use of 

enclosures (parking of vehicles, building access, and storage). Because owners lose living 

area, conversions usually are combined with the addition of an upper story or an elevated 

lateral addition (Section 6.4.2).

n Extend walls upward and raise the floor (A zones only). This measure leaves the building on 

its original slab-on-grade foundation. To achieve the necessary elevation of the lowest floor, 

the roof is removed and the walls are extended high enough to allow a new floor system to 

Measures to bring a building into 

compliance may include meeting 

a combination of requirements. For 

example, elevating a building on a 

new foundation may also require 

reinforcing the continuous load path 

and filling in below-grade areas.

An easy-to-read publication that illustrates three elevation options is 

Above the Flood: Elevating Your 

Floodprone House (FEMA 347).

A more technical document that 

describes additional options is 

Engineering Principles and Practices for Retrofitting Flood-Prone 

Residential Structures (FEMA 259).
SI/SD Desk Reference 

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

be constructed on top of the slab, with the new floor surface at or above the BFE. The work 

also may require the windows and doors to be shifted upward. In addition to replacing the 

roof, the work also involves retrofitting the newly-created “crawlspace” or under-floor space 

(the space between the original slab and the new floor) to be a compliant enclosure by 

installing flood openings. In some cases, rather than adding a new floor system, it may be 

feasible to simply add sufficient thickness to the slab to raise the floor surface to or above 

the BFE.

n Conversion of walkout basement to a compliant enclosure (A zones only). This measure is 

particularly appealing if the elevation of the floor above the walkout basement is at or above 

the BFE. If that is the case, converting the walkout basement to a compliant enclosure can 

be done by limiting the use of the area to parking of vehicles, building access, or storage; 

removing finish materials; retrofitting the enclosure walls with flood openings; and elevating 

equipment and utility service. To prevent the enclosure from being a basement as defined 

by the NFIP, particular attention must be paid to ensuring that the enclosure has at least one 

side that is at or above grade, which may require lowering the ground surface by re-grading 

along one or more of the exterior foundation walls. 

n Dry floodproofing modifications (A zone only, non-residential only). Dry floodproofing 

measures must be designed and certified by a qualified registered professional engineer or 

architect. Designers must consider many factors when determining whether a building can 

be dry floodproofed, including the strength of the building, whether it will be subject to 

buoyancy once it is made watertight, whether all possible paths for water to enter the building 

can be properly sealed (floor drains, plumbing fixtures, openings through exterior walls 

through which utility service is provided, etc.), and whether there is adequate warning time 

if human intervention is necessary (e.g., to install barriers or closing valves). For guidance, 

see ASCE 24-05, Flood Resistant Design and Construction and FEMA FIA-Technical Bulletin 3, 

Non-Residential Floodproofing – Requirements and Certification for Buildings Located in Special Flood 

Hazard Areas.

6.3.2	 Enclosures

The NFIP regulations allow enclosed areas below elevated buildings provided the enclosures 

meet certain requirements. The NFIP regulations for enclosures under buildings in A zones are 

in 44 CFR § 60.3(c)(5), and in § 60.3(e)(5) for enclosures under buildings in V zones. Requirements in these sections include:

n Limited use. In all flood zones, the use of enclosures must be limited to parking of vehicles, 

building access, and storage. Crawlspaces are treated as enclosures.

n Flood damage-resistant materials. All construction materials used below the BFE must be 

flood damage-resistant materials (see FEMA Technical Bulletin 2, Flood Damage-Resistant 

Materials Requirements for Buildings Located in Special Flood Hazard Areas). Materials necessary 

to meet fire protection code requirements are acceptable.

n Elevated or protected utility equipment and service. Given the limitations on use, only 

the minimum utility equipment and service connections necessary should be located in 

enclosures under elevated buildings. 
6- SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

n Flood openings. In A zones, the walls of enclosed areas must have flood openings to allow 

for the automatic entry and exit of floodwaters to minimize the potential for damage caused 

by hydrostatic pressure (see FEMA Technical Bulletin 1, Openings in Foundation Walls and

Walls of Enclosures Below Elevated Buildings in Special Flood Hazard Areas). 

n Breakaway walls. In V zones, the walls of enclosed areas must be non-supporting breakaway 

walls (see FEMA Technical Bulletin 9, Design and Construction Guidance for Breakaway Walls 

Below Elevated Buildings Located in Coastal High Hazard Areas). 

6.3.3	 Basements

Under the NFIP, new buildings and substantially improved buildings must have their lowest 

floors (including basements) elevated to or above the BFE (non-residential buildings may have 

dry-floodproofed basements below the BFE). The NFIP regulations define a basement as “any 

area of the building having its floor subgrade (below ground level) on all sides.” If a local official determines that work constitutes SI/SD of any building that has a basement, the building 

must be brought into compliance, which includes eliminating the below-grade area. 

Measures to eliminate basements below the BFE will, in part, depend on the nature of the basement and surrounding ground elevations. Below are examples of measures that can be taken to 

meet the requirement:

n Fill in below-grade areas. This option is effective only if the elevation of the floor above the 

below-grade area is at or above the BFE. Compliance is achieved by filling in the below-grade 

area and converting the remaining headroom to a compliant enclosure. 

n Convert walkout basements to compliant enclosures. Section 6.3.1 describes how a walkout

basement can be modified to become a compliant enclosure (A zone only).

n Floodproof below-grade areas (A zone, non-residential only). The NFIP regulations allow nonresidential buildings in A zones to have areas that are below-grade on all sides (basements) 

only if the areas are dry floodproofed. Careful evaluation of the structural integrity of a 

building must be undertaken to determine if dry floodproofing measures are feasible. For 

guidance, see FEMA FIA-Technical Bulletin 3, Non-Residential Floodproofing – Requirements and 

Certification for Buildings Located in Special Flood Hazard Areas.

6.3.4	 Utility and Building Service Equipment

The NFIP requires that new buildings and substantially improved buildings have utilities, equipment, and appliances elevated to or above the BFE, or be designed to prevent water from 

entering or accumulating within the equipment components (see 44 CFR § 60.3(a)(3) provided in Section 3.3). This means that SI/SD buildings with utility and building service equipment 

that is below the BFE must have the equipment either elevated or replaced with components 

that are designed and installed to be flood damage-resistant. Minimal electric service is allowed 

below the BFE if it is required to address life safety and electric code requirements for building 

access and storage.
SI/SD Desk Reference 6

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

Below are examples of measures that can be taken to meet NFIP requirements for utility and 

service equipment:

n Relocate to elevated areas. Equipment and utility service must be relocated or elevated when 

buildings are elevated-in-place or if ground floors are converted to compliant enclosures. 

When a basement is eliminated, any equipment that was in the basement will be relocated 

to the elevated portion of the building or to an elevated addition.

n Elevate on outside platforms. Equipment located 

outside of the building, such as heat pumps and air 

conditioning units, must be elevated on platforms at 

or above the BFE. Platforms may be independently 

supported or cantilevered from the foundation.

n Elevate on platforms inside enclosures. If a substantially improved building in an A zone has a compliant 

enclosure, utility equipment (e.g., water heaters, water 

treatment systems, and heat pumps) may be installed on platforms that raise the equipment 

to or above the BFE. Note that appliances such as washers, dryers, and freezers should not be 

installed in enclosures (even if elevated) because they are not compatible with the allowable 

uses (parking of vehicles, building access, and storage) and they do not meet the mechanical 

service equipment requirement at 44 CFR § 60.3(a)(3).

n Provide component protection. Equipment that must be located on the floor of a compliant 

enclosure in an A zone may be protected with a barrier to keep water away from the 

equipment. Typical barriers are constructed of masonry or concrete to a height that is equal 

to or higher than the BFE and have specially designed doors or panels that are put in place 

to keep water from entering. This approach is feasible in non-residential buildings provided 

there is sufficient warning time. 

6.3.5	 Flood Damage-Resistant Materials

The NFIP requires that flood damage-resistant materials be used below the BFE. If a building 

will be elevated-in-place, materials used below the BFE must meet this requirement, including 

materials used to build an enclosure. For guidance on materials, see FEMA Technical Bulletin 2, 

Flood Damage-Resistant Materials Requirements for Buildings Located in Special Flood Hazard Areas.

Minimal use of certain materials that are not flood damage-resistant materials is allowed below 

the BFE if specifically required to address life safety and electric code requirements for building 

access and storage areas.

6.3.6	 Making Buildings Reasonably Safe from Flooding

In all flood zones, substantially improved buildings must be “adequately anchored to prevent 

flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy” (see 44 CFR § 60.3(a)(3)(i) provided in 

Section 3.3). In addition, in V zones structures must be “anchored to resist flotation, collapse, 

More detail on compliant installations can be found in Protecting 

Building Utilities from Flood Damage: Principles and Practices for 

the Design and Construction of 

Flood Resistant Building Utility 

Systems (FEMA 348).
6- SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

and lateral movement due to the effects of wind and water loads acting simultaneously on all 

building components” (see 44 CFR § 60.3(e)(4)(ii) provided in Section 3.3). The compliance 

solution selected for any given building will depend on several factors such as the flood zone in 

which it is located, the type of foundation, and whether the building is residential or non-residential.

Below are examples of measures that can be taken to meet the NFIP requirement that buildings 

be reasonably safe from flooding:

n Continuous load path. Provide for a continuous load 

path by connecting the building to the foundation 

and connecting the roof to the walls. If existing 

connectors (bolts, nails, screws, straps, etc.) that 

attach the building to the foundation are inadequate, 

they should be replaced, reinforced, or augmented to 

address the requirement that the building be stable 

under base flood conditions.

n Foundation bracing. Pile- or post-supported buildings 

may require additional bracing. In V zones, bracing 

that is perpendicular to the approach of waves is an 

obstacle to the passage of waves and water under the 

building, and may need to be modified to meet the 

NFIP requirement to be “free-of-obstruction.” 

6.4	 Illustrations of Improvements and Repairs

The following sections and Tables 6-1a and 6-1b present some examples of common improvements and repairs, along with descriptions of measures to comply with the NFIP floodplai

management requirements. Several of the examples describe and illustrate a specific type of 

work or combinations of work that may trigger the SI/SD requirements. Examples are also given of improvements and repairs to pre-FIRM and post-FIRM buildings and what must be done 

to comply with the new construction requirements of the NFIP. Examples of work include:

n Rehabilitation and remodeling (Section 6.4.1

n Lateral additions (Section 6.4.2)

n Vertical additions (Section 6.4.3)

n Repair, reinforce, or replace foundations (Section 6.4.4)

n Repair of damaged buildings (Section 6.4.5)

n Reconstruction of demolished or destroyed buildings (Section 6.4.6)

n Work on post-FIRM buildings (Section 6.4.7

n Work on buildings where flood maps have been revised (Section 6.4.8

Work that does not require a permit is generally considered to be 

repairs of normal wear and tear 

or routine maintenance. Property 

owners or contractors should check 

with local officials to determine 

when work requires a permit. 

Once the requirement for a permit 

is triggered, all work is to be included in the SI/SD determination, 

even work that would otherwise 

not require a permit. 
SI/SD Desk Reference 

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

Table 6-1a. Compliance Matrix (A Zones)

Types of Work Building is Pre-FIRM Building is Post-FIRM

Rehabilitation (renovate 

or remodel), not SI

Compliance not required Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance

Rehabilitation (renovate 

or remodel), SI

Building required to comply Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance 

(see Note below table)

Lateral addition and 

Rehabilitation, SI

Addition required to comply; 

building required to comply

Addition required to comply; building required to 

comply (see Note below table) 

Lateral addition, not SI Addition not required to comply Addition required to be elevated to at least the 

elevation of the existing lowest floor

Lateral addition, SI, not

structurally connected

Addition required to comply; 

building not required to comply

Addition required to comply 

Lateral addition, SI, 

structurally connected

Addition required to comply; 

building required to comply 

Addition required to comply; building required to 

comply (see Note below table)

Vertical addition above 

building, not SI

Compliance not required Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance

Vertical addition above 

building, SI

Building required to comply Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance 

(see Note below table)

Repair foundation, not 

SI

Compliance not required Repairs shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance

Repair foundation, SI Building required to comply Building required to comply (see Note below 

table)

Replace/extend 

foundation, SI (including 

"elevate-in-place")

Building required to comply Building required to comply (see Note below 

table)

Repair damage, SD Building required to comply Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance 

(see Note below table)

Reconstruct new 

building on existing or 

new foundation, SI

Reconstructed building required 

to comply

Reconstructed building required to comply (see 

Note below table)

Note: If a map revision has resulted in a higher BFE, a post-FIRM building must comply based on the new BFE. 
6-10 SI/SD Desk Referen

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

Table 6-1b. Compliance Matrix (V Zones)

Types of Work Building is Pre-FIRM Building is Post-FIRM

Rehabilitation (renovate 

or remodel), not SI

Compliance not required Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance

Rehabilitation (renovate 

or remodel), SI 

Building required to comply Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance 

(see Note below table) 

Lateral addition and 

Rehabilitation, SI

Addition required to comply; 

building required to comply 

Addition required to comply, and rehabilitation 

work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance 

(see Note below table)

Lateral addition, not SI Addition not required to comply Addition required to comply 

Lateral addition, SI, not

structurally connected

Addition required to comply; 

building required to comply 

Addition required to comply (see Note below)

Lateral addition, SI, 

structurally connected

Addition required to comply; 

building required to comply 

Addition required to comply; building required to 

comply (see Note below table)

Vertical addition above 

building, not SI

Compliance not required Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance

Vertical addition above 

building, SI

Building required to comply Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance 

(see Note below table)

Repair foundation, not 

SI

Compliance not required Repairs shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance

Repair foundation, SI Building required to comply Building required to comply (see Note below 

table)

Replace/extend 

foundation, SI (including 

"elevate-in-place")

Building required to comply Building required to comply (see Note below 

table)

Repair damage, SD Building required to comply Work shall comply and shall not be allowed to 

make the building non-compliant with any aspect 

of the building that was required for compliance 

(see Note below table) 

Reconstruct new 

building on existing or 

new foundation, SI

Reconstructed building required 

to comply

Reconstructed building required to comply (see 

Note below table)

Note: If a map revision has resulted in a higher BFE, a post-FIRM building must comply based on the new BFE. 

6.4.1	 Rehabilitation and Remodeling

The NFIP considers rehabilitation and remodeling to include improvements to a building that 

do not affect the external dimensions nor expand the total area of the building. Rehabilitation may or may not involve structural modification of the building. The local official must 

review all work proposed for rehabilitation or remodeling to determine whether it constitutes a 
SI/SD Desk Reference 

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

substantial improvement. If the work constitutes a substantial improvement, the building must 

be brought into compliance.

Rehabilitation of pre-FIRM buildings (residential)

Residential buildings that are substantially improved through rehabilitation or remodeling 

must comply with all applicable NFIP floodplain management requirements for the specific 

flood zone. Figure 6-1 illustrates the rehabilitation of a residential building that is located in

an A zone. The figure illustrates elevation on a solid perimeter wall (crawlspace). Other types 

of foundations may be used in A zones, including pilings, columns, slabs on fill, and stem walls. 

Open foundations (pilings and columns) are required in V zones.

Rehabilitation of pre-FIRM buildings (non-residential)

Rehabilitation or remodeling work on a non-residential building that is SI/SD triggers the requirement that the lowest floor be elevated (in A and V zones) or dry floodproofed (only in A 

zones). 

Figure 6-2 illustrates the rehabilitation of a non-residential structure in an A zone where a 

structural engineering analysis indicates the building can be retrofitted with dry floodproofing 

measures in compliance with the NFIP requirements that require certification of the design by 

a registered design professional. For additional guidance, see FEMA FIA-Technical Bulletin 3, 

Non-Residential Floodproofing – Requirements and Certification for Buildings Located in Special Flood 

Hazard Areas. Communities that enforce building codes that refer to ASCE 24-05 for design and 

construction of buildings in flood hazard areas should be aware that ASCE 24-05 establishes 

Figure 6-1. Rehabilitation or remodel (no increase in footprint) of residential building in an A zone – the proposed

work was determined to be a substantial improvement. The building is brought into compliance by elevating it on

an extended perimeter foundation wall, installing flood openings, and raising the HVAC equipment onto a platform.
6-12 SI/SD Desk Referen

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

some specific limitations for floodproofing, including limitations on warning time and the availability of adequate labor to implement floodproofing measures.

Depending on the type of foundation and other constraints, non-residential structures that are 

located in A zones may be elevated on raised foundations. In this instance, the building must 

be brought into compliance with all of the applicable floodplain management requirements, 

including the type of foundation, limitations on use of enclosed areas, installation of openings 

in any enclosed areas, elevation of utilities and mechanical equipment, and use of flood damage-resistant materials.

In V zones, the only compliance option for non-residential buildings is elevation on open foundations. Dry floodproofing is not allowed in V zones. 

Rehabilitation/repair of a post-FIRM building

Any repairs or improvements associated with the rehabilitation or remodeling of a post-FIRM 

building must comply with the NFIP requirements and not alter the building in any way that 

violates those requirements. 

If a revised, higher BFE goes into effect and the local official determines that rehabilitation 

constitutes SI/SD, the entire post-FIRM building must be brought into compliance with the elevation requirement based on the revised BFE. 

6.4.2	 Lateral Additions

A lateral addition expands the floor area of the building. A lateral addition that involves no alteration of the load-bearing structure of the building, is attached to the building with minimal 

Figure 6-2. Rehabilitation or remodel (no increase in footprint) of non-residential building in an A zone – the

proposed work was determined to be a substantial improvement. The building is brought into compliance by

retrofit dry floodproofing measures (certification of design by registered design professional is required).
SI/SD Desk Reference 6

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

connection, and that has a doorway as the only modification to the common wall is considered 

to be “not structurally connected.” A lateral addition that has its load-bearing structure connected to the load-bearing structure of the base building, which typically involves significant 

alternation of the common wall, is considered “structurally connected.”

If a lateral addition is proposed along with other work on the original building, all the work 

must be considered in the SI/SD determination, regardless of the size or cost of the addition by 

itself and the cost of improvements to the original building. 

As described below and summarized in Tables 6-1a and

6-1b, lateral additions depend on four factors:

n Whether the building is pre-FIRM or post-FIRM,

n Whether the common wall with the original building 

is modified structurally by more than installing a 

doorway, 

n Whether the addition itself is a substantial improvement, and 

n The applicable flood zone.

Lateral additions to pre-FIRM buildings (A zone, residential)

For a project that involves only a lateral addition (i.e., there will be no improvements to the original building, the addition will not be structurally connected to the original building, and only a 

doorway will be installed in the common wall between the addition and the original building):

n If the cost of the addition compared to the value of the original building constitutes a 

substantial improvement, only the lowest floor of the addition must be elevated to comply 

with NFIP requirements (Figure 6-3).

n If the addition is determined to not be substantial improvement, the addition is not required 

to be elevated. Owners should be reminded that the addition will be subject to flooding and 

encouraged to consider measures to reduce vulnerability to damage (Section 5.8).

If a proposed lateral addition project also includes rehabilitation or remodeling of the existing 

building, then the local official must consider the whole project as a combination of work. If the 

local official determines that the combined cost of the project constitutes substantial improvement, then both the original building and the addition must be elevated and meet all other 

applicable requirements (Figure 6-4).

Structurally Connected and Not 

Structurally Connected. A noncompliant addition that is below the 

BFE and “structurally connected” 

would transfer flood loads imposed 

on it to the existing building.

An addition that is below the BFE 

and “not structurally connected” is 

expected to sustain damage, but 

should not transfer loads to the existing building.
6-14 SI/SD Desk Referen

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

Figure 6-4. Lateral addition to a pre-FIRM building in an A zone – the proposed work includes an addition and

work on the original building, including structural modification of the common wall or roof. The proposed work

was determined to be a substantial improvement. The addition complies with all requirements and the building is

brought into compliance by elevating it on a compliant foundation.

Figure 6-3. Lateral addition to a pre-FIRM building in an A zone – the proposed work is only the addition (no work

was performed on the original building and no structural modification was made to the common wall or roof). The

addition constitutes a substantial improvement and it complies with all NFIP requirements.
SI/SD Desk Reference 6

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

Lateral additions to pre-FIRM buildings (V zone, residential)

Lateral additions to pre-FIRM buildings in V zones are treated differently than additions to 

buildings in A zones. If a proposed addition (or combination of an addition and other improvements) to a V zone building constitutes a substantial improvement, then the lowest floor of 

both the original building and the addition must be elevated (Figure 6-5). The pertinent NFIP 

requirement for elevating both is the “free of obstruction” requirement. The original building 

must be elevated so that it will not obstruct floodwaters and waves that may damage the addition. 

For more guidance, see FEMA Technical Bulletin 5, Free-of-Obstruction Requirements for Buildings 

Located in Coastal High Hazard Areas. 

Lateral additions to pre-FIRM manufactured homes

Lateral additions are common improvements to manufactured homes and local officials must 

determine whether the proposed work constitutes substantial improvement. Costs associated 

with typical porches and sunrooms may not exceed 50 percent of the market value of the home. 

However, proposed additions that will be walled with siding, insulated, and used year-round 

require close examination to determine whether the addition constitutes a substantial improvement. 

If a proposed addition to a manufactured home constitutes a substantial improvement, the local 

official must determine the applicable NFIP elevation requirements; the requirements depend 

on several factors that are described in Section 6.5.2. 

Figure 6-5. Lateral addition to a residential building in a V zone – the proposed work includes work on the original

building. The lateral addition and improvements constitute substantial improvement. Both the addition and the

original building are brought into compliance by elevating to or above the BFE on an open foundation.
6-16 SI/SD Desk Referen

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

Figure 6-6 illustrates a lateral addition to a pre-FIRM manufactured home – the proposed work 

includes improvements to the existing home. The existing home in this illustration is located 

outside a manufactured home park or subdivision and the work constitutes a substantial improvement. Both the addition and the home must be elevated on compliant foundations. 

All substantial improvements must be carefully constructed, supported, and anchored to resist flotation, collapse, and lateral movement during base flood conditions so as not to impose 

unanticipated loads on the original homes. Otherwise, the presence of additions could increase 

vulnerability to flood loads imposed on supporting piers and anchoring, leading to damage. For 

more detailed guidance on the installation of manufactured homes in SFHAs, see FEMA P-85,

Protecting Manufactured Homes from Floods and Other Hazards: A Multi-Hazard Foundation and Installation Guide. 

Lateral additions to pre-FIRM buildings (A zone, non-residential)

If a proposed lateral addition to a non-residential building is determined to be a substantial 

improvement, but there is no work proposed for the original building and the common wall is 

modified only by the installation of a door, only the addition must be brought into compliance. 

The addition must meet NFIP requirements either by elevating the lowest floor to or above the 

BFE or by dry floodproofing to that elevation (Figure 6-7). If the addition is dry floodproofed,

the common wall must also be made watertight.

Figure 6-6. Lateral addition to a pre-FIRM manufactured home in an A zone – the proposed work includes

improvements to the existing home. The work constitutes substantial improvement. The addition and the home

are elevated to or above the BFE.
SI/SD Desk Reference 

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

Figure 6-7. Lateral addition to a non-residential building in an A zone – the proposed work is only the addition (no

work on the existing building and no structural modification of the common wall or roof). The work constitutes

substantial improvement. The addition is elevated to or above the BFE (an alternative would be to dry floodproof

only the addition, including the common wall).

Lateral additions to post-FIRM buildings (any zone, residential or non-residential)

Lateral additions to post-FIRM buildings are new construction and must comply with the NFIP 

requirements, including elevation. If the addition does not comply, then the original building 

will become non-compliant. Lateral additions must not alter any aspect of the building that had 

to be met when the building was constructed in compliance with the community’s floodplain 

management regulations. A lateral addition, regardless of its value or size, must be elevated to 

at least the height of the post-FIRM building. The following summarizes these points:

n In any zone, if the BFE is unchanged, the addition must be elevated and comply with other 

applicable NFIP requirements, regardless of whether it is SI/SD (Figure 6-8).

n In any zone, if a revised, higher BFE is in effect, a lateral addition that is not a substantial 

improvement must be elevated at least as high as the original building. 

n In any zone, if a lateral addition is a substantial improvement (and structurally connected), 

both the addition and the building must be brought into compliance. If a revised, higher 

BFE is in effect, both the original building and the addition must be elevated.

n In A zones, if the lateral addition is a substantial improvement (and not structurally 

connected), it must be elevated to the effective BFE. The effective BFE may be higher than 

the BFE in effect when the building was built (Figure 6-9). 

n In V zones, if a lateral addition is a substantial improvement (and not structurally connected), 

both the addition and the original post-FIRM building must be elevated if a revised, higher 

BFE is in effect, otherwise the free-of-obstruction requirement is not met. 
6-18 SI/SD Desk Refere

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

Figure 6-9. Lateral addition to a post-FIRM building in an A zone (a map revision has increased the BFE).

The proposed work is a lateral addition with no work in the original building and no structural modification

of the common wall or roof. The work constitutes a substantial improvement. Because there is no structural

modification, only the addition must comply with the effective BFE which is higher than the BFE when the building

was built. If instead the proposed work includes work in the original building or structural modification, the

addition and the building must comply with the effective BFE.

Figure 6-8. Lateral addition to a post-FIRM building in any flood zone (map revision has not changed the effective

BFE). All improvements or repairs to a post-FIRM building must comply with the NFIP requirements regardless

of the value of that work, and the work shall not compromise any of the NFIP requirements that the building was

required to meet when it was initially built.
SI/SD Desk Reference 6

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

Figure 6-10. Vertical addition to a pre-FIRM residential building (in any zone) – the proposed work is a new upper

story that involves structural modification. The work is a substantial improvement. The building is elevated to or

above the BFE on a compliant foundation.

6.4.3	 Vertical Additions

A vertical addition expands the floor area of a building by either adding an upper story above the 

original building (Figure 6-10) or elevating the original building and constructing a new story beneath it (Figure 6-11). In both cases, it is likely that work on the load-bearing foundation will 

required to carry the added load. Vertical additions may be smaller than the building footprint, 

such as a loft or bedroom, but the local official must still make an SI/SD determination. 

Figure 6-11. Vertical addition to a pre-FIRM residential building (in any zone) – the proposed work is a new lower

story that involves structural modification. The work constitutes a substantial improvement. The building and the

new lower story are elevated on a compliant foundation.
6-20 SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

Vertical additions to pre-FIRM buildings (residential)

If a vertical addition to a pre-FIRM residential building constitutes a substantial improvement, 

the original building must be elevated to or above the BFE. In addition, the foundation must 

be modified or reconstructed (and below-grade areas filled in) to be compliant with applicable 

NFIP requirements based on the flood zone. 

Vertical additions to pre-FIRM buildings (non-residential)

Vertical additions may involve adding an upper story above a non-residential building (Figure 

6-12). If a vertical addition constitutes a substantial improvement, the original building must

be elevated to or above the BFE or dry-floodproofed to the BFE (A zone only). In addition, the 

foundation must be modified or reconstructed (and below-grade areas filled in) to be compliant with applicable NFIP requirements based on the flood zone. 

Vertical additions to post-FIRM buildings

Whether a local official will need to evaluate a vertical addition to a post-FIRM building to determine if it is a substantial improvement is related to whether the FIRM has been revised. If a 

revised, higher BFE is in effect, or if the flood zone changed (or floodway boundary changed), 

a vertical addition that is a substantial improvement will require that the entire building be elevated to the higher, effective BFE and comply with other applicable NFIP requirements based 

on the flood zone. 

Figure 6-12. Vertical addition to a pre-FIRM, non-residential building in an A zone. The work constitutes a

substantial improvement. The building is brought into compliance by retrofit dry-floodproofing measures

(certification of design by registered design professional is required). Non-residential buildings can also be

brought into compliance by elevation (not shown).
SI/SD Desk Reference 6

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

6.4.4	 Repair, Reinforce, or Replace Foundations

It is common to repair, reinforce, or replace foundations, especially for older buildings. Foundation work also includes repair of damaged foundations, regardless of whether the damage is 

caused by a single event (such as a flood or earthquake) or due to deterioration over time. 

Work performed on a foundation, either by itself or in combination with other work on a building, may constitute SI/SD. If the work is not a substantial improvement, the structure does 

not have to be elevated. However, any owner contemplating the replacement of a foundation 

should investigate the potential savings on the cost of NFIP flood insurance if the building is 

elevated and the new foundation complies with all of the applicable NFIP requirements. Many 

owners elect to elevate flood-prone buildings to reduce flood damage. The incremental cost to 

both replace a foundation and elevate a structure properly to the effective BFE may be offset by 

the reduction in future damage and annual flood insurance premiums.

In some cases, property owners may elect to elevate a structure, but not to the BFE. The cost to 

elevate a structure in this fashion must be included when making the SI/SD determination.

Foundation work on pre-FIRM buildings (residential)

If foundation work is determined to be SI/SD, then the building must be elevated in accordance 

with all applicable NFIP requirements, depending on the flood zone. Figure 6-13 illustrates the

construction of a compliant foundation under an existing home.

Foundation work on pre-FIRM buildings (non-residential)

If the foundation work on a non-residential building is determined to be SI/SD, then the building must be elevated in accordance with all applicable NFIP requirements, depending on the 

flood zone. 

Figure 6-13. New foundation or repair of foundation under a pre-FIRM (in an A zone) residential building. The

work was determined to be a substantial improvement. The building is brought into compliance by elevating on a

compliant foundation.
6-22 SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

As part of foundation work, owners of non-residential buildings in A zones may propose to 

retrofit with compliant dry-floodproofing measures. Such proposals must be supported with 

structural engineering analyses that indicate whether the buildings can be dry floodproofed in 

compliance with the NFIP requirements. The analyses must be prepared or reviewed by a registered design professional who must sign and seal the dry floodproofing designs. For guidance, 

see FEMA FIA-Technical Bulletin 3, Non-Residential Floodproofing – Requirements and Certification for Buildings Located in Special Flood Hazard Areas. The technical bulletin includes planning 

considerations regarding warning time, safety of personnel responsible for implementing the 

measures, and the importance of having an emergency operations plan and a plan for regular 

inspection and maintenance. ASCE 24-05, the standard for flood damage-resistant design and 

construction that is referenced by the model building codes, also includes similar requirements 

and limitations on measures that require human intervention.

6.4.5	 Repair of Damaged Buildings

The NFIP requirements for repair of substantially damaged buildings are the same as those 

described for rehabilitation and remodeling (Section 6.4.1). However, if a proposal for repair

also includes an addition to a damaged property, the cost of the addition must be included in 

the SI/SD determination. If the combination of work is a substantial improvement, then both 

the addition and the original building must be brought into compliance with the NFIP requirements, depending on the flood zone.

6.4.6	 Reconstruction of Demolished or Destroyed Buildings

Any project that involves complete reconstruction, such as rebuilding on the same foundation, 

is new construction that must comply with all applicable NFIP floodplain management requirements. A building that is totally destroyed or so significantly damaged that it cannot be repaired 

is a substantially damaged building. Sometimes an owner elects to demolish the building. In 

these circumstances, if the decision is to reconstruct using the existing foundation, the reconstructed building must meet NFIP requirements for new construction. 

6.4.7	 Work on Post-FIRM Buildings

All repairs, improvements or modifications to a post-FIRM building are considered new construction (see definition in Chapter 3). Work on a post-FIRM building must not be allowed if 

it would make the building non-compliant with the floodplain management requirements that 

had to be met when the building was constructed. Tables 6-1a (A zones) and 6-1b (V zones

identify types of work on post-FIRM buildings and the compliance requirements that apply. In 

some cases when an addition is involved, the original building has to be brought into compliance. 

6.4.8	 Work on Buildings Where Flood Maps Have Been Revised

Section 5.6.11 explains that many communities have had revisions to their flood hazard maps

The following illustrate how map revisions that change flood zone designations or modify or 

add floodway delineations must be taken into consideration:
SI/SD Desk Reference 6-

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

n If the FIRM has been revised and the SFHA has widened to include more area, that area is 

now subject to the NFIP requirements. For example, areas that were previously designated 

X zone may now be shown as A zone or V zone. Improvements and repairs to buildings that 

were outside of the SFHA but are now in the revised SFHA must be evaluated to determine 

if the work is SI/SD. 

n If the FIRM has been revised and the flood zone or BFE changed, a determination that work 

is a substantial improvement requires that the building meet NFIP requirements for new 

construction based on the revised flood zone and revised BFE. 

n If the FIRM has been revised and either the floodway boundaries are changed or a floodway 

is newly delineated, a determination that improvements or repairs to a building are SI/SD 

may require an encroachment analysis.

6.5	 Requirements for Certain Structures

This section describes how SI/SD is addressed for certain types of buildings in accordance with 

the NFIP floodplain management requirements, including: 

n Historic structures (Section 6.5.1

n Manufactured homes (Section 6.5.2)

n Accessory structures and certain agricultural structures (Section 6.5.3)

6.5.1	 Historic Structures

The NFIP gives special consideration to the unique value of designated historic buildings and 

structures. Provided such structures retain their designations, communities do not have to require them to be brought into compliance if they will be substantially improved or have been 

substantially damaged. Section 3.4.1 includes the NFIP’s definition for “historic structures.” The

term includes structures that are: (1) listed or preliminarily determined to be eligible for listing in the National Register of Historic Places; (2) certified or preliminarily determined by the

Secretary of the U.S. Department of Interior as contributing to the historical significance of a 

registered historic district or a district preliminarily determined to qualify as a registered historic district; or (3) designated as historic site under a State or local historic preservation program 

that is approved by the Secretary of the U.S. Department of Interior. The definition does not 

include structures that are merely old, those that residents refer to as historic, or those that happen to be located in historic districts. 

The NFIP floodplain management requirements contain two provisions that are intended to 

provide relief for historic structures located in SFHAs: 

(1) The NFIP definition of “substantial improvement” includes the following exclusion for

historic structures: “Any alteration of a ‘historic structure,’ provided that the alteration will not 

preclude the structure’s continued designation as an ‘historic structure’.” The exclusion also applies to historic structures that have been substantially damaged. This provision allows 

communities to exempt historic structures from the SI/SD requirements of the NFIP. 
6-24 SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

(2) The other provision of the NFIP floodplain management regulations that provides relief 

for historic structures” is the variance criteria at 44 CFR § 60.6(a). This provision states: 

“Variances may be issued for the repair or rehabilitation of historic structures upon a determination 

that the proposed repair or rehabilitation will not preclude the structure’s continued designation as 

a historic structure and the variance is the minimum necessary to preserve the historic character and 

design of the structure.” This provision allows communities to handle applications for work 

on historic structures by issuing variances. 

To address the unique needs of preserving historic structures, communities may elect to use one 

of the two approaches, either granting variances or exempting historic structures from the SI/

SD requirements. Whichever approach is selected, it must be used in all cases when improvements or repairs are proposed for historic structures. 

Using the variance option allows communities to evaluate individual requests and place conditions on the variance to make historic buildings more flood damage-resistant and to minimize 

flood damage. However, such conditions should not affect the historic character and design of 

the building. 

It is important to note that additions to historic structures that are located in floodways require 

additional attention. While additions may not have to meet the substantial improvement requirements, they must still satisfy the NFIP requirements related to floodway encroachments. 

A floodway encroachment analysis must be provided to demonstrate that an addition will not 

cause any increase in the BFE (Section 5.6.8).

Applications for improvements to historic structures should be accompanied by two pieces of 

evidence: (1) documentation that confirms the building is designated an historic structure; and

(2) documentation that confirms the proposed work will not preclude the structure’s continued 

designation. Applicants can ask the appropriate qualified entity that makes such designations 

to review their construction plans. A copy of the findings should be kept in the community’s 

permanent records.

Although compliance is not required for substantial improvement of historic structures, owners should carefully consider the benefits of implementing measures to minimize flood damage. 

State historic preservation agencies may have resources to help owners evaluate feasible measures. Historic buildings can be elevated on raised foundations, relocated to sites outside of 

SFHAs, or retrofitted with measures that reduce risk from flooding. FEMA’s Floodplain Management Bulletin: Historic Structures (FEMA P-467-2) provides guidance for communities and owners

of historic structures.

6.5.2	 Manufactured Homes

Communities that participate in the NFIP must issue permits for the placement of manufactured homes in SFHAs. This includes the placement of new manufactured homes, replacement 

of existing manufactured homes, substantial improvement of manufactured homes, and repair 

of substantially damaged manufactured homes. This requirement applies even if the community does not otherwise regulate the installation of manufactured homes. 
SI/SD Desk Reference 6-

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

The NFIP regulations define the following terms pertaining to manufactured homes:

n “Manufactured home” means a structure, transportable in one or more sections, which is built on 

a permanent chassis and is designed for use with or without a permanent foundation when attached to 

the required utilities. The term ‘manufactured home’ does not include a ‘recreational vehicle.’

n “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided 

into two or more manufactured home lots for rent or sale. 

n “New manufactured home park or subdivision” means a manufactured home park or subdivision 

for which the construction of facilities for servicing the lots on which the manufactured homes are to 

be affixed (including, at minimum, the installation of utilities, the construction of streets, and either 

final site grading or the pouring of concrete pads) is completed on or after the effective date of floodplain 

management regulations adopted by a community. 

n “Expansion to an existing manufactured home park 

or subdivision” means the preparation of additional sites 

by the construction of facilities for servicing the lots on which 

the manufactured homes are to be affixed (including the 

installation of utilities, the construction of streets, and either 

final site grading or the pouring of concrete pads).

n “Existing manufactured home park or subdivision”

means a manufactured home park or subdivision for which 

the construction of facilities for servicing the lots on which 

the manufactured homes are to be affixed (including, at minimum, the installation of utilities, the 

construction of streets, and either final site grading or the pouring of concrete pads) is completed before

the effective date of floodplain management regulations adopted by a community.

As described below, most manufactured home placements and substantial improvements are 

subject to the same NFIP performance standards that apply to typical, site-built residential structures. A limited exception to the elevation requirements also is described below: under certain 

conditions, the exception applies to the placement of manufactured homes in existing manufactured home parks or subdivisions. 

In AE, A1-30, and AH zones, the NFIP minimum requirement at 44 CFR § 60.3(c)(6) requires

manufactured homes (including substantially improved homes) to be placed on permanent 

foundations such that their lowest floors are elevated to or above the BFE. In AO zones, the requirement is for lowest floors to be elevated above the highest adjacent grade at least as high as 

the depth number specified on the FIRM. Manufactured homes must be securely anchored to 

an adequately anchored foundation system to resist flotation, collapse, and lateral movement. 

In V zones, the NFIP minimum requirement at 44 CFR § 60.3(e)(8) requires manufactured

homes (including substantially improved homes) to be placed on permanent foundations such 

that the lowest horizontal structural members (generally the bottom of the chassis frame) are 

elevated to or above the BFE. Manufactured homes must be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement. And, as with 

other buildings in V zones, foundations must be designed to withstand flood forces. 

A manufactured home park is 

usually owned by a single owner 

who rents pads and/or units.

A manufactured home subdivision is similar to traditional subdivisions in that each lot is individually 

owned. 
6-26 SI/SD Desk Referenc

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

In both A zones and V zones, the above-described requirements apply to sites that are: 

n Outside of a manufactured home park or subdivision (individually owned parcels),

n In a new manufactured home park or subdivision, 

n In an expansion to an existing manufactured home park or subdivision, or

n In an existing manufactured home park or subdivision on which a home has incurred 

substantial damage as a result of a flood. 

The exception in the NFIP regulations allows an alternative to the requirement to elevate the 

lowest floors of manufactured homes to the BFE [44 CFR § 60.3(c)(12) and § 60.3(e)(8)]. Th

exception is applicable only for placements or substantial improvements on lots in existing 

manufactured home parks and subdivisions. It allows the chassis of a manufactured home to be 

elevated on reinforced piers or other foundation elements of at least equivalent strength that 

are no less than 36 inches in height above grade. Although the NFIP allows this exception, communities should consider requiring full elevation in flood hazard areas where the floodwaters 

are known to be swift or more than 3 feet deep because these conditions pose greater risk to 

vulnerable manufactured homes and their occupants.

NFIP requirements for the substantial improvement of manufactured homes are the same as 

for residential structures. Specifically, a lateral addition that is determined to be a substantial 

improvement is illustrated in Figure 6-6. In this case, both the addition and the existing manufactured home must be elevated. 

For additional information on the placement and substantial improvement of manufactured 

homes in SFHAs, see FEMA P-85, Protecting Manufactured Homes from Floods and Other Hazards: A

Multi-Hazard Foundation and Installation Guide. 

6.5.3	 Accessory Structures and Certain Agricultural Structures

Floodplain management requirements, including the elevation and SI/SD requirements, apply 

to accessory structures and agricultural structures. Whether improvements, repairs, or additions to agricultural structures are proposed, local officials must make determinations based on 

costs and market values. If the work is SI/SD, the requirements apply and accessory structures 

and agricultural structures must be brought into compliance.

FEMA recognizes that wet floodproofing may be appropriate for accessory structures (garages and sheds only) 

and certain types of agricultural structures. Certain agricultural structures that qualify for this treatment are those 

located in wide, expansive floodplains, including farm 

storage buildings, grain bins, corn cribs, and general purpose barns. All other agricultural structures must 

comply with the NFIP requirements for non-residential 

structures, Homes that are built on farms are not agricultural structures and they must fully comply with the NFIP 

Wet floodproofing means permanent or contingent measures applied 

to a structure and/or its contents that 

prevent or provide resistance to damage from flooding by allowing water 

to enter the structure. For specifics, 

see FEMA FIA-Technical Bulletin 7, 

Wet Floodproofing Requirements 

for Structures Located in Special 

Flood Hazard Areas.
SI/SD Desk Reference 6

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

requirements. For additional guidance, see FEMA FIA-Technical Bulletin 7, Wet Floodproofing Requirements for Structures Located in Special Flood Hazard Areas

In accordance with the requirements for issuance of variances (Section 5.6.7), communities

may grant variances for substantial improvement of accessory structures and certain agricultural 

structures to allow the use of wet floodproofing measures in lieu of elevation. However, such 

variances may be granted only if the following conditions are satisfied:

n For certain agricultural structures, the structure is used solely for the parking of agricultural 

vehicles and machinery, the storage of crops, or the temporary sheltering of livestock;

n For accessory structures, the structure is used only for parking of vehicles and storage;

n The structure is designed and built in such a manner that results in minimal damage to the 

structure and its contents, including being anchored to resist flotation, collapse, and lateral 

movement;

n Flood damage-resistant materials must be used below the BFE;

n Mechanical and utility equipment must be elevated or floodproofed to or above the BFE;

n If in the floodway, the floodway encroachment requirements must be satisfied; and

n There will be no additional threats to public safety.

Communities should carefully evaluate improvements made to accessory structures and agriculture structures. If a property owner intends to change the use of the structure to a residential use 

or other non-residential use, then the work proposed must be evaluated to determine whether 

it is a substantial improvement.

6.6	 NFIP Flood Insurance Implications

The flood insurance rating structure used by the NFIP 

uses three primary factors:

n Flood zone (A zone or V zone);

n Date of construction (pre-FIRM or post-FIRM), 

including the date of construction of substantial 

improvements; and

n For post-FIRM buildings, the elevation of the lowest 

floor compared to the BFE as evidenced by surveyed 

elevation data (or for floodproofed non-residential 

buildings, the height of the floodproofing relative to 

the BFE).

The NFIP requires that substantially improved or substantially damaged buildings be brought into compliance. 

NFIP flood insurance policies on those buildings are written using rates based on elevation. In 

most cases, the premium will decrease when a pre-FIRM building is substantially improved and 

Rates used for pre-FIRM structures 

are called “subsidized” or discounted 

rates. An NFIP policy can be purchased without providing elevation 

data that are obtained by a survey.

Rates used for post-FIRM structures 

(and pre-FIRM structures that are 

substantially improved) are called 

“elevation” rates because they depend on the elevation of the lowest 

floor relative to the BFE. Elevation 

rates are considered to be “actuarial.” To be properly rated, surveyed 

elevation data are required.
6-28 SI/SD Desk Referen

6 FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE

brought into compliance. The building becomes a post-FIRM building and premiums are calculated using elevation rates. 

When questions arise concerning how a proposed improvement might affect a flood insurance 

policy, it is always best to encourage property owners to obtain a cost estimate from an insurance 

agent. Table 6-2 indicates how compliance with the SI/SD requirements affects how policies are 

rated. Figure 6-14 illustrates an example of how the cost of an NFIP policy will vary, depending

on how a substantially damaged home is repaired. 

Table 6-2. Substantial Improvement and NFIP Flood Insurance Implications

Description of Work NFIP Flood Insurance Implications

Pre-FIRM Interior renovation only, work constitutes SI; 

whole building brought into compliance by 

elevating the lowest floor at or above the BFE.

Or

Structurally-connected lateral addition or 

second story addition, work constitutes SI; 

whole building brought into compliance.

Policy is written using post-FIRM elevation 

rates based on a survey of new lowest floor 

elevation at or above the BFE.

Pre-FIRM Interior renovation only, work constitutes SI; 

building is NOT elevated in compliance with 

the requirements (i.e., it is a violation).

Or

Second story addition, work constitutes SI; 

building is NOT elevated in compliance with 

the requirements (i.e., it is a violation).

Policy is written using post-FIRM elevation 

rates based on a survey of new lowest 

floor below the BFE, which may result in a 

significantly higher flood insurance premium.

Or

If the owner refuses to address the violation 

and bring the building into compliance, the 

community may cite the structure as a violation 

in accordance with Sec. 1316 of the National 

Flood Insurance Act of 1968, which allows the 

NFIP to deny flood insurance on all insurable 

buildings on the property (Section 5.6.13).

Pre-FIRM Lateral addition not structurally connected 

(connecting door only), work constitutes SI and 

only the addition is elevated.

Policy is written using subsidized rates 

because the original building is unchanged.

Post-FIRM Lateral addition, regardless of value; addition 

is not elevated, thus, the building is not in 

compliance (i.e., it is a violation).

Policy is written using elevation rates based on 

the elevation of the lowest floor of the addition, 

which may result in a significantly higher flood 

insurance premium.
SI/SD Desk Reference 6-

FACTORS TO CONSIDER AND ILLUSTRATIONS OF SUBSTANTIAL IMPROVEMENT AND REPAIR OF SUBSTANTIAL DAMAGE 6

Figure 6-14. The cost

of NFIP flood insurance

policy varies depending

on how a substantially

damaged building is

repaired. This illustration

is for $150,000 in

structure coverage with

the rates as of October

2009. The figure is for

comparison purposes

only.

7	 Substantial Damage in the

Disaster Recovery Environment

7.1 	 Overview

Following a disaster, local officials will often have many 

additional duties and face the challenge of fulfilling them 

with few resources. Local officials may encounter a large 

number of damaged structures and a high volume of permit applications. Most property owners want to repair and 

rebuild as quickly as possible. Sometimes there is pressure 

on local officials to waive requirements that are perceived 

to hamper getting back to normal, including pressure to waive the substantial damage requirements. Yielding to such pressure would expose people and their properties to future damage. 

The recognition that returning to “normal” leads to repetitive flood damage was one of the 

driving forces behind the creation of the NFIP. To effectively meet the substantial damage requirements of their local regulations, local officials will have to rapidly perform a large number 

of inspections and substantial damage determinations.

Developing standard procedures can help communities better manage post-disaster recovery. 

This chapter describes ways to estimate repair costs and market values for large numbers of 

damaged buildings. Section 7.5 briefly describes FEMA’s Substantial Damage Estimator (SDE). 

The manuals that accompany this computer-based tool include specific recommendations for 

collecting building data in advance, developing protocols, conducting inspections, and producing reports that support making substantial damage determinations and preparing substantial 

damage determination letters. Using this tool, and other methods described in this chapter, can 

help local officials provide reasonable and defensible substantial damage determinations. 

This chapter offers guidance for communities to handle the unique challenges following a disaster event and to prepare an effective and efficient response. It also includes a very brief overview 

of damage assessments and building evaluations that may help local officials after disasters, and 

describes some effective measures communities can take to clearly communicate the substantial 

damage requirement in their floodplain management regulations and codes.

7.2	 Preparing for Post-Disaster Recovery

There are several ways that communities can effectively administer their floodplain management responsibilities in the post-disaster recovery period. Some successful actions include:

n Brief all elected officials, as soon as possible after the event, of the community’s responsibilities 

to:

Waiving permit fees and inspection 

fees is a common post-disaster action taken by many communities. 

However, waiving fees does not 

waive the requirement for permits.

SI/SD Desk Reference 7
7 SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT

n Issue permits for repair and reconstruction,

n Make substantial damage determinations for buildings that are located in the mapped 

SFHA, 

n Explain what it means to bring a substantially damaged building into compliance with 

current floodplain management standards, 

n Explain NFIP Increased Cost of Compliance insurance coverage (Section 7.6), and

n Share the materials developed to communicate with citizens. 

n Ask electric utility companies and community utility departments to turn on service only if 

the owner provides a copy of a building permit or evidence that a permit is not required.

n Establish a routine to drive through affected areas to check for unpermitted construction 

work and ask the police and other departments to report on activities that may not be 

authorized by permit.

n Depending on the scale and severity of damage, some communities institute a full or partial 

moratorium on issuing permits. Once the community has evaluated the magnitude, scope, 

and general location of potentially substantially damaged structures, the community may 

remove the moratorium. When mitigation projects such as floodplain buyouts, elevation-inplace, or other measures are considered, it may be reasonable to delay rebuilding until the 

pros and cons of such projects are evaluated (Chapter 8).

n Keep records in a format that allows plotting by a geographic information system (GIS) 

to easily document the status of each damaged building, including those that have been 

inspected, those with pending permit applications, those that have been determined to 

be substantially damaged, those with permits, and those that have been inspected during 

construction. 

Communities that have extensive floodplains and significant numbers of flood-prone buildings 

are encouraged to plan ahead to handle the workload. Despite good planning, support may 

be necessary to handle large numbers of damage inspections and permit applications. In addition to support from the State and FEMA, resources may be available from other communities, 

State floodplain management associations, State building code associations, and organizations that represent engineers and architects. Some States and communities develop mutual 

aid agreements, interlocal agreements, or some other mechanism to facilitate this post-disaster 

support. While help may be offered to perform inspections and gather data, the final SI/SD determinations and permit decisions remain the responsibility of the local official in the affected 

community. 

7.2.1	 Sources of Assistance

Many technical issues can arise when inspecting damaged buildings and making substantial 

damage determinations. For matters related to the floodplain management requirements of 

local regulations and building codes, local officials are encouraged to contact their NFIP State 

Coordinating Agency or the appropriate FEMA Regional Office (Appendix A). After disasters, 

training or other assistance may be available from FEMA on how to use SDE such as collecting 

information on damaged buildings. 

7- SI/SD Desk Referenc
SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT 7

7.3	 Assessing Building Damage

Although every disaster is unique, local officials can anticipate and prepare for many of the 

activities that take place after large-scale events. This section is intended to highlight those activities that relate to identifying substantially damaged buildings. 

7.3.1	 Preliminary Damage Assessments

Immediately after large-scale events that cause major damage, community and State officials 

typically undertake an initial “windshield review” of the extent of damage. This survey yields a 

broad characterization of the number of buildings affected and the level of anticipated damage. 

It usually is a precursor to a decision regarding whether to seek a declaration of the event as a 

major disaster. 

Typically, this initial survey is followed by an official Preliminary Damage Assessment (PDA). PDAs are performed 

by teams of representatives from FEMA and/or the State. 

Local building officials and floodplain managers can participate in PDAs, which usually are coordinated by local 

emergency managers. 

The PDA augments the initial reports from communities regarding the scope, magnitude, and 

impact of an event on individuals, families, businesses, and public property. The PDA teams view 

the damage first-hand, assess the scope of damage, and develop gross estimates of repair costs. 

The information is used to determine whether Federal disaster assistance should be requested 

by the Governor and forms the basis for the disaster declaration. The PDA also identifies any 

unmet needs that may require immediate attention.

Local officials charged with performing building inspections and making substantial damage 

determinations may find the results of the PDA useful to identify areas where significant damage has occurred and to coordinate their substantial damage inspections. 

7.3.2	 Rapid Evaluations and Detailed Safety Evaluations

Depending on the scope of an event and severity of damage, some communities conduct a rapid evaluation of 

damaged areas as a preliminary step before detailed evaluations are performed. 

Rapid evaluations, sometimes called “building condition 

surveys," typically are based on an exterior inspection. They are conducted to:

n Identify buildings that appear to be so damaged that they are unsafe and should not be 

reentered without a detailed inspection of structural integrity, and

n Identify buildings that appear to have damage sufficient to require a permit before they can 

be repaired or reoccupied. 

Preliminary Damage Assessments 

are performed to broadly characterize the extent of damage – they 

are not equivalent to substantial 

damage determinations.

Safety evaluations are performed to 

identify unsafe buildings – they are 

not equivalent to substantial damage determinations.

SI/SD Desk Reference 7
7 SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT

These rapid evaluations can also help local officials determine the scope of an event and the 

level of effort that will be required to perform building-by-building inspections, review permit 

applications, collect substantial damage data, and perform inspections once recovery work is 

underway.

One method for conducting rapid evaluations is described in ATC 45, Field Manual: Safety Evaluation of Buildings after Windstorms and Floods. This document, produced by the Applied Technology 

Council (ATC, http://www.ATCouncil.org), is not a manual for making substantial damage determinations. It provides guidelines and procedures for conducting both rapid evaluations and 

more detailed evaluations to determine whether damaged buildings are safe for use or if entry 

should be restricted or prohibited.

Most communities perform additional detailed safety evaluations when buildings have sustained 

significant damage. The purpose of the evaluations is to identify restrictions on building access 

and use. For complex buildings and many non-residential buildings, the evaluation may lead 

the local official to conclude that it is appropriate for the owner to submit an independent engineering evaluation. In addition to describing methods for conducting rapid evaluations, ATC 

45 includes a method for conducting detailed evaluations. ATC 45 and other sources recommend posting damaged buildings with one of three notices:

n Inspected (typically a green placard). This signifies that no apparent hazard was identified, 

that the original lateral- and vertical-load capacity is not significantly decreased, and there 

are no restrictions on use or occupancy. It does not mean that work can proceed without a 

permit. 

n Restricted Use (typically a yellow placard). This signifies that the safety of the building is 

questionable or hazardous conditions exist or are believed to exist and warrant restrictions on 

occupancy and reuse. Further evaluation is necessary (which may or may not be performed 

by the local official). 

n Unsafe (typically a red placard). This signifies that an extreme hazard or unsafe situation is 

present and there may be a significant risk of further damage or collapse. These buildings 

are unsafe for occupancy or entry, except as authorized by the local official. A “red tag” is 

not a demolition order, although such an order may be issued depending on subsequent 

evaluations. 

7.4	 Using Estimates of Repair Costs and Market Values to Screen

for Substantial Damage

Some readily-available data can be used to estimate repair costs and market values. The sources 

of estimates described below can be used to “screen” damaged buildings for those that are most 

likely to have sustained substantial damage. Comparing readily-available information on repair 

costs to readily-available information on market value can give local officials a basic picture of 

which structures will require more attention and more detailed information in order to make 

substantial damage determinations. While the sources of information listed below should not 

be used to make final substantial damage determinations, local officials can use them to organize and focus efforts following a disaster.

7- SI/SD Desk Referenc
SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT 7

When using estimates in this manner, there is no firm rule to determine how close to 50 percent 

is close enough to warrant requiring additional effort to improve the accuracy of the data. Each 

community should decide in advance, based on its selected method of making estimates, how 

close is close enough. For example, as described below, a community may decide to use easilyobtained estimates for screening purposes. The local official may then decide that, using those 

estimates, if the ratio of estimated costs compared to estimated market value is less than 40 percent, no further evaluation is necessary because the work obviously does not constitute SI/SD. 

Using that same logic, the community may decide that, if the ratio is greater than 60 percent, no 

further evaluation is necessary because the work obviously constitutes substantial damage. 

Continuing this example, the question then becomes what should the local official do when the 

ratio, based on estimates, falls between the bounds of 40 percent and 60 percent. The local official may require the applicant to provide a detailed list of costs (materials and labor) and/or to 

obtain a professional appraisal of the market value of the building (Section 4.5.1). Alternatively,

if the local official has evidence that an estimate reflects actual repair costs (or actual market 

values), those estimated costs and values may be used for the final SI/SD determination.

Local officials will still be responsible for administering their standard permit requirements 

and procedures for structures that fall outside the parameters of their screening efforts. In the 

example above, permits will still be required for structures where the ratio is more than 60 percent and those with a ratio of less than 40 percent. Local officials can reexamine the substantial 

damage requirements during the review of those permit applications.

7.4.1	 Insurance Estimates of Repair Costs

Property owners who have insurance will receive estimates of damage from their insurance companies. For 

a number of reasons, these estimates are not sufficient 

for local officials to make substantial damage determinations. The basis used by adjusters to estimate damage and 

the costs to repair are governed by the terms of the insurance policy. The insurance estimate may not cover all 

costs associated with repairing a structure to its pre-damage condition, which is the basis that communities must use. 

After floods, adjusters who handle NFIP claims are instructed to submit an Adjuster Preliminary 

Damage Assessment form to FEMA if a building appears to have been substantially damaged 

(FEMA Form 81-109, in Appendix D). The form provides information about a damaged building, including Probable Repair Cost, Building Replacement Cost Value, and Building Actua

Cash Value. Local officials can use this information for screening purposes to help identify 

those buildings that should be examined more closely. Because Federal flood insurance does 

not cover all damage that local officials must consider when determining substantial damage, 

the reported Probable Repair Cost may underestimate the total cost to repair. In addition, the 

Building Replacement Cost Value and the Building Actual Cash Value may not be equivalent to 

market value. After floods, communities should contact the NFIP State Coordinating Agency or 

FEMA Regional Office to determine if this information is available. 

Only the community is legally responsible for making SI/SD determinations. 

Information from insurance claims 

may help screen for substantial damage, but cannot be used as the basis 

for final determinations. 

SI/SD Desk Reference 
7 SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT

If insurance claims data are available from property owners for buildings damaged by events 

other than flooding, the same limitations apply. While local officials may find such data useful 

for screening, claims data must not be used as a proxy for the costs of repair to make substantial 

damage determinations.

7.4.2	 Unadjusted Assessed Values as Estimates of Market Values

Section 4.5.2 describes using adjusted assessment values that are developed by applying an adjustment factor to property assessment values provided by the local property assessment authority

to yield a reasonable estimate of market value. In the post-disaster period, unadjusted assessed 

values may be used as estimates of building market value to quickly screen damaged buildings 

to help focus attention on those for which more detailed information has to be provided. 

7.4.3 	 Replacement Cost Values as Estimates of Market Values

Replacement cost value (RCV) means the cost to replace a building on the same parcel with a 

new building that is intended for the same purpose and using comparable materials and quality 

(at the present day cost of materials and labor). The concept of RCV is used by the insurance 

industry and the construction industry. Definitions may vary from State to State. 

RCV can be estimated easily, even when a large number of damaged buildings must be assessed. 

Therefore, local officials may find it useful to use RCV to estimate market values in the post-disaster period to screen all damaged buildings. 

The older and more deteriorated a structure is, the greater the potential for a difference between RCV and market value. Thus, local officials who use RCV estimates for screening are 

advised to set a low threshold for the ratio of cost to repair to RCV, such as 30 percent. In that

case, any building that the screening indicates has a ratio value of greater than 30 percent would

be examined carefully to ensure that valid cost estimates and market values are used in the substantial damage determinations. 

A number of commercial sources of construction cost information are available to support estimating the replacement cost of a building, including industry-accepted guides available from 

companies such as RSMeans (http://www.rsmeans.com) and the Craftsman Book Company 

(http://www.craftsman-book.com), among others. These sources allow computation of construction costs based on occupancy, square footage, quality, and regional cost variations. 

7.5	 Damage Assessments for Substantial Damage Determinations

Communities have choices about how to handle making substantial damage determinations 

when many buildings have been damaged by a significant event:

n They can proactively inspect buildings soon after the event and use available information to 

estimate repair costs and market values; those data can then be used to develop substantial 

damage determinations in advance of owners submitting applications with more detail; or 

7- SI/SD Desk Referenc
SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT 7

n They can notify owners of the requirement to get permits and then wait for property owners 

to apply for permits and make substantial damage determinations at that time, following 

their normal permit review procedures.

The first option offers a number of benefits that should make it easier to administer the SI/SD 

requirements. One benefit is to provide property owners with information about the requirement to bring buildings into compliance before they get very far along with their plans to repair. 

Another benefit is that owners that have Federal flood insurance policies will more quickly receive the community’s substantial damage determination that they need in order to submit a 

claim for ICC coverage to their adjuster (Section 7.6). The second option may pose more of 

a challenge to the community because many people begin repairs without getting permits. In 

addition, by the time owners apply for permits, they may have hired design professionals to develop plans for repairs and improvements that do not take into consideration the requirement 

to bring SI/SD buildings into compliance.

7.5.1	 FEMA’s Substantial Damage Estimator Software

FEMA’s SDE software offers a formalized approach to 

develop reasonable estimates of building values and reasonable estimates of the cost to repair or reconstruct 

buildings. The SDE enables local officials to calculate a 

reasonable and defensible estimate of whether a building 

has been substantially damaged. Local officials can use 

these results from the software to make substantial damage determinations. 

The SDE is described in the FEMA Substantial Damage Estimator (FEMA P-784 CD).

 This publication includes a 

User’s Manual and a Field Workbook. Together they focus on using the SDE tool to perform 

field evaluations and post-event data collection, as well as pre-planning before an event. 

Originally developed for single-family homes and manufactured homes, the 2010 version of SD

now includes a component that will allow it to be used for common non-residential structures 

(e.g., office buildings, strip malls, restaurants, grocery stores, convenience stores, department 

stores, schools, etc.). However, SDE is not designed for estimating damage to unique buildings 

and buildings designated by State or Federal entities as “historic structures.” The SDE also is an 

effective tool to use even if only one or a few buildings are damaged. The SDE Field Workbook 

includes worksheets that are useful even if the software is not used. SDE includes worksheets for 

single/multi-family buildings, manufactured homes, and certain non-residential buildings. 

While SDE can be used to evaluate damage by any cause (flood, tornado, earthquake, etc.), 

flooding is the most frequently-occurring natural hazard. Therefore, the software and companion workbook focus primarily on developing inventories of flood-damaged structures.

Communities may request assistance with SDE:

n FEMA offers training workshops 

on SDE.

n FEMA may deploy personnel to 

help local officials use SDE after 

disasters

1 Replaces and expands the 2001 version of the Residential Substantial Damage Estimator (FEMA 311) and the 2003 version of 

the RSDE Workbook (FEMA 311WB).

SI/SD Desk Reference 
7 SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT

The SDE software allows the user to develop damage estimates by examining individual building 

elements. Users are able to estimate damage percentages for each described building element. 

Using these percentages, SDE produces an aggregate “percent damage” for the structure as a 

whole. 

SDE is customizable, allowing users to develop estimated repair costs and market values, or to 

input professional estimates or valuations. To develop estimates for repair costs and market 

value, SDE is intended to be used in conjunction with an industry-accepted, construction costestimating guide such as RSMeans© Residential Cost Data Book, RSMeans© CostWorks, and the 

Craftsman© National Building Cost Manual. The SDE is designed for use by local officials or others who have some experience and knowledge of residential and non-residential construction 

costs and practices. 

Building-specific attributes that affect the estimates that the software produces are inputted 

by the user. The required attributes include the quality of construction (low, budget, average, 

good, and excellent), foundation type, number of stories, square footage, superstructure type, 

exterior finish, roof covering, and presence of HVAC systems. Additional inputs are requested 

for non-residential buildings, including building use, presence of elevators, escalators, and fire 

suppression systems. 

Photographs of each inspected building can be uploaded and stored with the software and later 

retrieved for reports. Fields allow input of latitude and longitude coordinates acquired onsite 

using a handheld global positioning system (GPS) device. Figure 7-1 shows how the data can be

displayed on geographically registered images such as digital aerial photography, Google Earth, 

and NASA’s World Wind. 

Users can define their own reports or use one of the ten pre-determined report formats:

1. Community Report for all residential structure

2. Community Report for all non-residential structure

3. Community Report for residential structures that appear to be substantially damage

4. Community Report for substantially damaged non-residential structures

5. Structure and Percent Damage Report for all residential structures

6. Structure and Percent Damage Report for all non-residential structures

7. Structure and Percent Damage Report for substantially damaged residential structures

8. Structure and Percent Damage Report for substantially damaged non-residential structures

9. Summary Report for all residential structures

10. Summary Report for all non-residential structure

7- SI/SD Desk Referenc
SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT 7

The Community Reports noted above include the following information (Structure and Percent Damage Reports include only items 1,2 and 6

1. Community name and identification number

2. Owner first and last names, building address, community, State, and zip cod

3. Basis for value of building (computed actual cash value from the SDE software, adjusted

tax assessed value, or professional appraisal)

4. Basis for costs to repair (computed damage from the SDE software, contractor’s estimate, 

or community estimate)

5. Type of structure (single-family, town or row house, manufactured home, or non-residential)

6. Estimate of percent damaged (results of comparing the estimated cost to repair to the 

estimated building value)

7.6 	 Increased Cost of Compliance Coverage

NFIP flood insurance policies on buildings include ICC coverage. This coverage was authorized by Congress to help pay the added costs of bringing buildings that are repetitively or 

Figure 7-1. SDE data

displayed using mapping

software.

SI/SD Desk Reference 
7 SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT

substantially damaged by flooding into compliance with 

the community’s floodplain management requirements 

for new construction. 

ICC claims are paid after direct physical loss caused by 

flooding and:

n The building is determined by the community to be 

substantially damaged, or

n If the community has adopted a “repetitive loss” or 

cumulative substantial improvement provision that requires compliance based on flood 

damage that occurs two times in a 10-year period ending on the second event, where the

cost to repair the damage equals or exceeds 25 percent of the building’s pre-damage market

value on each occurrence (Section 5.7.3).

ICC payments are made to help pay for the following mitigation options that bring buildings into compliance: 

n Elevation (including freeboard if required by the 

community) 

n Relocation 

n Demolition

n Dry floodproofing (non-residential buildings only)

Guidance on ICC is available in FEMA 301, Increased Cos

of Compliance Coverage: Guidance for State and Local Officials. 

This publication describes the coverage, conditions of eligibility, and the claims process. The roles of the insurance 

agent, claims adjuster, and policyholder are described. 

The community’s role is described in detail, including the 

following:

n Requiring compliance with all NFIP and local requirements.

n Collecting information and making substantial damage determinations.

n Informing property owners about the requirement to bring buildings into compliance and 

working with them to determine the appropriate options to achieve compliance.

n Providing the property owner/policyholder a letter with the substantial damage determination; the owner then provides a copy to the claims adjuster to process the ICC claim.

n Issuing permits and inspecting construction.

n Performing final inspections and issuing certificates of occupancy or letters that state the 

building has been brought into compliance and that no variance was granted; this evidence 

is required before policyholders can receive the final installment of their ICC claim 

payments.

An ICC claim can be made regardless of whether a flood results in a 

Presidential disaster declaration. 

In 2010, the ICC coverage could 

provide up to $30,000 towards the 

cost of bringing certain flood-damaged buildings into compliance.

In order for an ICC claim to be 

paid:

n Local officials must make SD 

determinations and work with 

owners to develop measures to 

bring buildings into compliance.

n Owners must file an ICC claim.

n Adjusters must verify key information and process claims. 

n The community issues permits 

for the work.

7-10 SI/SD Desk Referen
SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT 7

7.7	 Post-Disaster Permits and Inspections

The occurrence of a disaster that affects a large number of buildings does not alter a community’s responsibility to review permit applications, issue permits, inspect construction, and cite 

violations. All of those actions should be performed as usual (see FEMA 480, NFIP Floodplain 

Management Requirements: A Study Guide and Desk Reference for Local Officials). The only difference 

will be the volume of work and the number of owners who will need assistance. Chapter 5 of this 

Desk Reference describes community responsibilities for issuing permits and Chapter 4 offers 

guidance for estimating repair costs, improvement costs, and market values.

It is important that each permit application be carefully examined. Some damage may not have 

been readily apparent when post-disaster assessments were performed, some owners may decide to undertake improvements at the same time as repairs, or some owners may postpone 

repairs for many months. Each of these may alter the determination. Every permit file should 

contain the documentation necessary to support the finding that the work does – or does not 

– constitute SI/SD.

Even after a disaster, local officials should not assume that construction will proceed as spelled 

out in the permit application. Follow-up inspections are vital to ensure that applicants adhere 

to the permit requirements. Local officials should develop a plan to handle the increased number of permits and inspections.

7.8	 Appeals and Variances

After events that cause major damage, owners often seek relief from requirements to comply 

with building code and floodplain management requirements. There are two mechanisms 

through which such relief may be processed: appeals and variances.

Owners may appeal decisions, orders, and determinations made by local officials, including 

substantial damage determinations. Appeals are described in more detail in Section 5.6.6. Even 

in the post-disaster recovery period, appeals should be handled according to the community’s 

established process. 

Owners may request variances. A variance is a grant of relief from the terms of a land use, zoning, building code, or other regulation. If granted, it allows construction in a manner that is 

otherwise prohibited. Variances are described in more detail in Section 5.6.7. 

The NFIP regulation at 44 CFR § 60.6 outlines procedures for granting variances; these procedures must be followed even in the post-disaster recovery period (also see FEMA 480, NFIP 

Floodplain Management Requirements: A Study Guide and Desk Reference for Local Officials). If granted, variances are to provide only the minimum relief necessary. A variance should be rare, and 

granted only after due consideration. 

Especially when damage was caused by flooding, it is difficult to conceive of situations where 

it can be justified to waive the requirement to elevate buildings that were determined to have 

been substantially damaged. Local officials are required to advise owners that, even if approved 

SI/SD Desk Reference 
7 SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT

by a properly granted variance, buildings that have their lowest floors below the BFE may be 

rated for NFIP flood insurance using very high rates, resulting in costly premiums (see Section 

6.6). 

7.9	 Post-Disaster Communications with Property Owners

Communications with property owners will take place throughout the post-disaster recovery 

phase. Local officials should recognize that substantial damage determinations may generate a 

number of questions from home and business owners, and should be prepared to respond to 

these questions. This section provides local officials with guidance for communicating substantial damage information, and describes the following:

n Information about clean-up and repairs

n Information about permits

n Information about Increased Cost of Compliance coverage

n Interactions during damage inspections

n Providing substantial damage determination letters to owners

7.9.1	 Information About Clean-up and Repairs

The initial contacts with property owners are typically related to cleaning up, advising them 

that inspections must be conducted to determine the safety of buildings, reminding owners 

not to perform any work that requires a permit until permits are obtained, and advising them 

that substantial damage determinations must be made and that such determinations trigger the 

floodplain management requirement to bring buildings into compliance by elevating them (or 

by dry floodproofing, non-residential buildings only). Local officials can provide information 

to owners about the kinds of clean-up and repairs that may be performed prior to a substantial 

damage determination, including work necessary to temporarily stabilize a building so it is safe 

to enter, as well as trash removal and clean-up. 

Unless there are restrictions on entering areas that have sustained major damage, most owners 

and occupants start to clean up right away. There are many online sources of information to 

help with clean-up work, including http://www.fema.gov and http://www.redcross.org, among 

others. Copies of FEMA 234, Repairing Your Flooded Home may be available from local offices o

the American Red Cross (ARC) or copies may be ordered from the FEMA publication warehouse (see Appendix B for ordering instructions). This booklet was developed in partnership 

with ARC and FEMA. FEMA has other materials related to recovering from, and coping with, 

flood damaged property, available online at http://www.fema.gov/hazard/flood/coping.shtm. 

7.9.2	 Information About Permits

It is extremely important to make sure that property owners are informed about their responsibilities to obtain permits for repairs following disasters. Lack of information about permit 

requirements can cause many problems in the post-disaster period. FEMA’s SDE Field Workbook

7-12 SI/SD Desk Refere
SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT 7

(Section 7.5.1) includes samples of a press release, a notice that can be posted in affected areas,

and a handout that can be used to alert residents that inspections will be performed and permits may be required. 

Communities should consider developing and providing guidance to citizens and property owners on: 

n The importance of having damaged buildings inspected before repair work is started.

n Activities that require a permit. 

n The floodplain management requirements that apply when buildings in the SFHA are 

substantially damaged.

n Activities that do not require a permit (e.g., disposing of damaged contents and carpeting; 

cleaning floors, walls, and ductwork; or covering damaged roofs and windows).

n The availability and benefits of ICC coverage that is part of NFIP flood insurance policies on 

buildings in mapped SFHAs (Section 7.6). FEMA has developed a brochure that explains 

ICC (FEMA F-663, Increased Cost of Compliance Brochure) (see Appendix B for ordering

instructions).

n The importance of hiring licensed contractors and cautions about fraudulent and unlicensed 

entities that may take advantage of victims in areas that have been hit by a significant event.

n The importance of including damage-reduction measures to minimize future flood damage, 

even if such measures are not required by the community’s floodplain management 

regulations.

7.9.3	 Information About Increased Cost of Compliance Coverage

As described in Section 7.6, local officials should remind owners who have NFIP flood insurance 

policies that ICC coverage may help pay for the cost to bring buildings into compliance with 

local floodplain management requirements if it is determined that the building has been substantially or repetitively damaged. The local official should also provide guidance to property 

owners on mitigation options to bring buildings into compliance. Local officials should obtain 

copies of FEMA F-663, Increased Cost of Compliance Brochure and distribute it to property owners

as needed.

7.9.4	 Interactions with the Public During Damage Assessments

After disasters and while conducting damage assessments, local officials may be faced with many 

questions from property owners and occupants. Communities are encouraged to set guidelines for interactions between inspectors and owners so that inspectors can efficiently perform 

their work. Although some assessments may be performed without direct contact with property 

owners, detailed evaluations and use of FEMA’s SDE software tool typically require contact and 

coordination with owners. 

The inspector’s job is to inspect damaged buildings and collect data. Local officials should encourage inspectors to refrain from speculating or discussing the likely outcome of substantial 

SI/SD Desk Reference 
7 SUBSTANTIAL DAMAGE IN THE DISASTER RECOVERY ENVIRONMENT

damage determinations. Because the final determination must be made by the local official, discussions in the field may contribute to misinformation and confusion.

Before they are sent out to inspect damaged buildings, a meeting should be held with all inspectors to talk about the importance of consistent communication with owners and occupants. It is 

a good practice to set up a single point of contact to answer questions from owners, and inspectors should encourage people to call that contact. Not only does this improve the consistency of 

the information provided, but it will help inspectors get their jobs done more efficiently. 

Every inspector should carry an official letter that explains the purpose of the inspection and 

the requirement for owners to obtain permits for repair work. Inspectors should limit their interactions to collecting data. Some communities may direct inspectors to advise owners if they 

observe any ongoing work that should be suspended because a permit is required. If materials 

are available, inspectors can give owners a handout that explains the community’s permit requirements and procedures.

7.9.5	 Providing Substantial Damage Determination Letters to Owners

After inspections are completed and the data evaluated 

and substantial damage determinations are made, owners should be provided letters with the results. Appendix 

E includes examples of three letters:

n Letter to notify property owners of a determination 

that work constitutes substantial improvement

n Letter to notify property owners of a determination that work constitutes repair of substantial 

damage 

n Letter to notify property owners of a determination that work does not constitute repair of 

substantial damage

Understandably, people will have many questions about the determinations, including whether 

it can be appealed, what it means to bring a building into compliance, and how they can access 

the NFIP’s ICC claim payment (if they have NFIP flood insurance). As noted above, designating 

a single point of contact or contacts to discuss these questions with owners will ensure consistency. 

Communities that have developed 

mitigation plans may hold meetings 

or distribute materials to explain 

mitigation options and FEMA’s mitigation grant programs (Chapter 8).

7-14 SI/SD Desk Referen
8	 Mitigation Projects

8.1	 Overview

This chapter provides brief descriptions of common types of flood mitigation projects that 

are eligible for funding by FEMA’s five mitigation grant programs. Brief summaries of those 

programs are included. Because program priorities and policies change from time to time, communities that are interested in these programs should obtain current information from their 

State Hazard Mitigation Offices (see Appendix A). 

Many buildings that are damaged by flooding were built before communities adopted floodplain 

management regulations and Flood Insurance Rate Maps. Many of these pre-FIRM buildings 

have experienced repetitive flooding and some are vulnerable to significant floods and are 

likely to sustain substantial damage at some time. Communities may seek mitigation grants to 

address both problems.

Some of FEMA’s grant programs are funded annually and can be used to support projects 

in the “pre-event” period: Pre-Disaster Mitigation (PDM); Flood Mitigation Assistance (FMA); 

Repetitive Flood Claims (RFC); and Severe Repetitive Loss (SRL). One program, the Hazard 

Mitigation Grant Program (HMGP), is available only after major disasters are declared by the 

President. Many post-disaster mitigation projects include buildings that have sustained substantial damage. Projects that acquire properties, remove flood-prone buildings, and deed-restrict 

the land to open space, obviate the need for owners to bring buildings into compliance. Projects involving other measures that directly affect a building, such as elevation-in-place or dry 

floodproofing (non-residential buildings only in A zones), must be conducted in compliance 

with the community’s floodplain management regulations and codes.

HMGP and PDM are funded by general Treasury funds. FMA, RFC, and SRL are authorized under the NFIP and are funded by income collected by the NFIP. The NFIP-funded programs are 

focused primarily on mitigating flood losses sustained by NFIP-insured buildings, specifically 

those that have received multiple flood insurance claims, called repetitive loss properties. 

8.2 	 Mitigation Planning

In accordance with 44 CFR Part 201, State and local governments and Indian Tribal governments must have hazard mitigation plans as a condition for receiving hazard mitigation grants. 

The most common types of projects used to mitigate flood losses are described in Section 8.3 

and FEMA’s mitigation grant programs are briefly described in Section 8.4.

Mitigation planning refers to a process that leads a planning committee through a framework of 

steps to develop a mitigation plan. The primary objective of the planning process is to facilitate 

development of strategies that will reduce damage, protect people and property, and improve 

resistance to natural hazards. The process involves four basic steps:

SI/SD Desk Reference 
8 MITIGATION PROJECTS

1. Organize resources 

2. Identify hazards and assess risks

3. Develop a mitigation plan 

4. Implement the plan and monitor progress 

While eligible applicants for FEMA grant programs must have FEMA-approved mitigation plans, 

the benefits of mitigation planning go beyond simply qualifying for those funds. States, communities, higher education institutions, and other entities that undertake mitigation planning 

also consider the value of actions that improve disaster resistance by modifying programs and 

policies, such as adoption of more restrictive development standards, and initiating efforts to 

inform citizens about risks and steps they can take to reduce damage. 

FEMA’s guidance documents related to mitigation planning are online at http://www.fema.

gov/plan/mitplanning/index.shtm. 

8.3	 Types of Flood Mitigation Projects

This section provides brief descriptions of the most common types of mitigation projects that 

are implemented to reduce exposure to flooding. In practice, a single project may involve using 

one or more of these project types. 

8.3.1	 Identifying Flood Mitigation Projects

While mitigation planning is the first step, each property needs to be evaluated individually to 

determine which method is appropriate. Communities that engage in flood mitigation projects 

have many factors to evaluate before identifying the most effective type or types of activities that 

will both solve their problems and also meet other community objectives. Only communities 

can make those decisions, although many States help communities evaluate the many factors to 

consider. FEMA offers several tools to facilitate decision-making: 

n National Flood Mitigation Data Collection Tool (FEMA 497). This tool was developed for 

nationwide use to gather information about flood-prone structures in order to determine 

potentially appropriate long-term mitigation measures. The goal is a standardized, systematic 

approach to collecting and interpreting property data and mitigation project development. 

While the focus of the tool is data collection for repetitive loss properties, it can be used to 

gather information related to flood risk, building construction, and building value for any 

structure. 

n Reducing Damage from Localized Flooding: A Guide for Communities (FEMA 511). This nontechnical guide is intended to help local officials and others understand what can be done 

to reduce localized flood damage. It focuses on a community’s capability to minimize its 

existing localized flood problems and avoid future problems. It outlines the types of actions 

that can be taken, explains why they are important and what their potential benefits are, and 

points the reader to other sources.

8- SI/SD Desk Referenc
MITIGATION PROJECTS 8

n Selecting Appropriate Mitigation Measures for Floodprone 

Structures (FEMA 551). This manual provides 

guidance for interpreting data collected with the 

National Flood Mitigation Data Collection Tool and other 

sources, in order to develop detailed proposals for 

flood mitigation projects. The manual assumes that 

areas that are considered high priority for mitigation 

have been identified and the community is evaluating 

which types of mitigation measures will address specific 

problems. It identifies technical issues associated with 

mitigation measures and includes references to other 

documents that provide more detailed guidance. 

8.3.2	 Property Acquisition/Demolition and Relocation

FEMA and the States have encouraged communities to acquire and remove flood-prone buildings since the early 1990s. A property acquisition project involves the purchase of properties 

that have sustained flood damage or that may be subject to severe or repetitive flooding. Eligible acquisition projects are those where the property owner voluntarily participates. Buildings 

are either demolished or physically removed. Local and/or State governments agree to deed 

restrict the property so that it remains in open space in perpetuity to fulfill natural and beneficial floodplain functions. Acquisition projects can be planned to meet compatible objectives, 

including passive recreation, environmental education, or wetlands mitigation.

8.3.3	 Building Elevation

An elevation project involves detaching a building from its foundation and placing it on an 

NFIP- and code-compliant, taller foundation. The structure must be elevated as required by 

local regulations to be at or above the BFE or the post-disaster advisory BFE, if applicable. 

Although the costs and elevation methods vary, buildings with all types of foundations have 

been elevated, including those on crawlspaces, piers, or pilings. The cost to elevate a structure 

can vary greatly, depending on the elevation method used, condition of the structure, and the 

height above grade and other construction requirements. Elevation methods that require significant demolition or the construction of new living space may not be eligible for Federal grant 

funds. Communities interested in property elevation should consult their State Hazard Mitigation Office and FEMA’s program guidance.

Communities consider elevation instead of acquisition projects for many reasons: for buildings 

that are structurally sound; to avoid disconnected, publicly-owned lots; for buildings in areas 

with extensive floodplains where alternative sites are not available; and for buildings in highly 

attractive areas. While elevation-in-place projects reduce flood damage, other flood-related risks 

and needs continue. Communities will still have to provide warnings, residents will still have to 

be evacuated, emergency shelters will have to be opened, and lives will be disrupted.

FEMA 511 and FEMA 551 describe 

measures that reduce flood damage. 

Some of those measures may not 

result in full compliance and cannot 

be used to satisfy the requirement to 

bring substantially-damaged buildings into compliance. Some of the 

measures described may not be eligible for FEMA grant funding.

SI/SD Desk Reference 
8 MITIGATION PROJECTS

8.3.4	 Relocation

If flood-prone buildings are structurally sound, and if acceptable receiving sites are close by, a 

relocation project may be viable. Physically relocating buildings to sites outside of the SFHA 

reduces the risk of future flood damage and the vacated land can be retained in open space. Relocating a building is similar to elevation-in-place because the building must be detached from 

its foundation and placed on a new foundation. The difference is the process and equipment 

required to move a building over the distance and terrain to the receiving site. 

8.3.5	 Floodproofing for Non-Residential Structures or Historic Structures

Dry floodproofing involves sealing non-residential structures to be watertight so that floodwaters do not enter the 

building during base flood conditions. Modifications may 

include structural strengthening of walls, special doors 

and closures for other openings, application of waterproof 

membranes, measures to handle seepage, and other measures. A structural evaluation is necessary to determine 

whether a structure can withstand anticipated flood loads, 

especially hydrostatic pressure and buoyancy. Currently, 

only non-residential structures and residences that are 

listed as historic structures may be dry floodproofed. 

8.3.6	 Other Types of Projects

Other types of projects may reduce flood damage, but are not direct solutions for individual 

buildings that are substantially improved, unless the SFHA is revised: 

n Stormwater management. Stormwater management or drainage improvements can 

reduce the frequency and severity of flooding, but a property owner cannot propose such 

improvements in place of bringing a substantially damaged building into compliance. The 

exception is if a drainage project results in a revision of the SFHA in which the building is 

located, which may mean the building is no longer in the SFHA. 

n Minor localized flood reduction projects. For larger buildings or groups of buildings, one 

option may be to install or modify culverts, floodgates, or minor floodwall systems that 

protect an individual structure. Engineering analyses are necessary to determine if these 

measures are feasible and to determine their impacts on flood elevations. Only if a project 

qualifies for a map revision that removes areas from the SFHA would buildings no longer be 

subject to the SI/SD requirements. To be eligible under FEMA’s FMA, SRL, and RFC grants, 

the mitigation activity must protect structures that are insured by the NFIP.

8.4	 FEMA’s Mitigation Grant Programs

FEMA administers five mitigation grant programs. Fact sheets for the programs are available 

online at http://www.fema.gov/media/fact_sheets/mitigation.shtm. A chart that compares 

Compliance with the NFIP requirements cannot be achieved by using 

wet floodproofing measures in which 

floodwater is allowed to enter a 

building. An owner may elect to implement these measures unless a 

determination finds the work would 

constitute substantial improvement.

8- SI/SD Desk Referenc
MITIGATION PROJECTS 8

the programs (authorities, purpose, priorities, available funds, applicant and subapplicant 

eligibility, eligible project types, cost-share requirements, eligible management costs, planning 

requirements, application and review procedures, and deadlines) and links to descriptions of 

each program are found at http://www.fema.gov/government/grant/hma/grant_resources.

shtm, which also lists other resources to support mitigation planning and mitigation projects. 

8.4.1	 Elements Common to All Grant Programs

All of FEMA’s grant programs have certain required elements in common:

n Application submission. State emergency management agencies or similar offices of the 

States may apply directly to FEMA. Local governments and other applicants must submit 

applications through the State as subapplicants. Depending on the grant program, 

applications may be ranked by the State, FEMA, or a national evaluation panel. 

n Mitigation plan requirements. All States must have 

a FEMA-approved hazard mitigation plan. Except 

for the RFC program, local governments and Indian 

Tribal governments also must have FEMA-approved 

hazard mitigation plans.

n Feasibility and effectiveness requirement. Projects must 

be both technically feasible and effective at mitigating 

the flood hazard. Engineering analyses and project 

plans and specifications may be required to demonstrate feasibility and effectiveness.

n Cost-effectiveness requirement. Hazard mitigation assistance grants only fund cost-effective 

mitigation projects. A benefit-cost analysis is a well-established method for quantitatively 

comparing benefits and costs of projects. 

n Environmental and historic preservation. Applicants must answer a series of environmental 

and historic preservation review questions. All projects must meet the requirements of 

applicable Federal, State, Indian Tribal, and local laws, implementing regulations, and 

Executive Orders.

n Flood insurance requirement. For structures that will remain in the SFHA after a mitigation 

project is implemented, flood insurance policies must be maintained after the project is 

completed. 

n Non-Federal match. Recipients must provide the non-Federal share of the costs and cover 

all costs that are determined to be ineligible for funding by the grants. Many communities 

require property owners to cover these costs and some States may provide matching funds.

8.4.2 	Pre-Disaster Mitigation Program

The PDM program is a nationally competitive program that provides funds to States, local 

governments, and Indian Tribal governments for implementation of cost-effective hazard mitigation activities that complement a comprehensive mitigation program. The program provides 

applicants with an opportunity to raise risk awareness and reduce disaster losses through use of 

Each year, FEMA issues guidance 

for each grant program. Some priorities and limitations may change from 

year to year. Communities that are 

interested in these programs should 

contact their State Hazard Mitigation 

Officers (Appendix A).

SI/SD Desk Reference 
8 MITIGATION PROJECTS

grant funds to develop all-hazard mitigation plans and flood mitigation plans and to implement 

mitigation projects. 

Each year’s funding level is determined by Congress. A limit is placed on the maximum amount 

that a single project can receive and recipients must provide a cost-share of at least 25 percent of 

a project’s eligible costs. In addition to supporting development of mitigation plans, PDM funds 

can be used for flood mitigation projects, including:

n Elevation of existing public or private structures to at least the BFE or higher, if required by 

FEMA or if required by State or local regulations

n Voluntary acquisition and demolition or relocation of structures and real property for 

conversion to open space in perpetuity

n Relocation of public and private structures outside of the SFHA

n Dry floodproofing non-residential buildings and certain residences that are listed as historic 

structures 

n Stormwater management projects to reduce or eliminate long-term risk from flood 

hazards

n Localized flood reduction projects

n Protective measures for utility infrastructure to reduce or eliminate flood damage

8.4.3	 Hazard Mitigation Grant Program

HMGP funds are available following a Presidential disaster declaration. Eligible applicants 

include States, local governments, Indian Tribal governments, and some private non-profit organizations. Communities may apply for HMGP assistance on behalf of affected individuals and 

businesses, and all funds must be used to reduce or eliminate losses from future disasters. FEMA 

allows a portion of the funds to be used to support development of mitigation plans. At a minimum, recipients must provide a cost-share of at least 25 percent of a project’s eligible costs. 

HMGP provides each State that receives a major disaster declaration an amount of funding 

that is determined on a formula that is based on a percentage of funds spent by FEMA under 

the Public Assistance and Individual Assistance programs. Under the formula, States with approved Standard State Mitigation Plans receive 15 percent for the first $2 billion of estimated 

aggregate amounts of disaster assistance, 10 percent for disaster assistance amounts between $2 

billion and $10 billion, and 7.5 percent for amounts between $10 billion and $35.333 billion. 

States with approved Enhanced State Mitigation Plans receive 20 percent for the first $2 billion 

of estimated aggregate amounts of disaster assistance and the same percentages when assistance 

amounts exceed $2 billion. 

HMGP funds can be used for eligible activities that reduce damage from any natural hazard. Examples of flood mitigation projects that have been funded include:

n Elevation of existing public or private structures to at least the BFE or higher, if required by 

FEMA or if required by State or local regulations

8- SI/SD Desk Referenc
MITIGATION PROJECTS 8

n Voluntary acquisition and demolition or relocation of structures and real property for 

conversion to open space in perpetuity

n Relocation of public and private structures outside of the SFHA

n Dry floodproofing non-residential buildings and certain residences that are listed as historic 

structures 

n Stormwater management projects to reduce or eliminate long-term risk from flood hazards

n Localized flood reduction projects

n Protective measures for utility infrastructure to reduce or eliminate flood damage

Eligible subgrantees submit grant applications to the State, which sets mitigation priorities, 

performs technical reviews, and offers technical assistance. FEMA conducts the final eligibility 

review to ensure that all projects are compliant with Federal regulations, including the Federal 

law that requires States and communities to have FEMA-approved mitigation plans in place prior to receipt of HMGP project funds. 

8.4.4	 Flood Mitigation Assistance Program

The FMA program provides funding to States and communities for measures that reduce or 

eliminate the long-term risk of flood damage to buildings, manufactured homes, and other 

structures that are insured by the NFIP. Each State’s allocation is based on its percentage of 

NFIP policies. Subapplicants must be participating in the NFIP (not suspended or withdrawn). 

The program provides grants for mitigation planning and projects with the goal of reducing insurance claims, especially repetitive claims. All applicants must have a FEMA-approved hazard 

mitigation plan. At a minimum, recipients must provide a cost-share of at least 25 percent of a 

project’s eligible costs. The non-Federal cost share may be reduced to 10 percent if the State 

has a FEMA-approved mitigation plan that also addresses how the State has and will continue to 

reduce the number of severe repetitive loss properties. Examples of eligible projects include:

n Elevation of existing public or private structures to at least the BFE or higher, if required by 

FEMA or if required by State or local regulations

n Voluntary acquisition and demolition or relocation of structures and real property for the 

purpose of creating open space

n Relocation of structures outside of the SFHA

n Dry floodproofing of existing non-residential structures and certain residences that are 

listed as historic structures 

n Minor localized flood reduction projects where 50 percent of the structures that directly 

benefit from the mitigation activity are insured by the NFIP

8.4.5	 Repetitive Flood Claims Program

The RFC program is designed to reduce or eliminate the long-term risk of flood damage to 

structures that are insured by the NFIP and have received one or more NFIP flood insurance 

SI/SD Desk Reference 
8 MITIGATION PROJECTS

claim payments. RFC funds may only be used in a State or community that is participating in 

the NFIP and that cannot meet the requirements of the FMA due to lack of cost share or lack of 

capacity to manage grants. RFC grants are awarded to applicants on a nationwide basis without 

reference to State allocations, quotas, or other formula-based allocations. All grants are eligible 

for up to 100 percent Federal assistance.

Eligible mitigation activities include:

n Elevation of existing public or private structures to at least the BFE or higher, if required by 

FEMA or if required by State or local regulations

n Voluntary acquisition and demolition or relocation of structures and real property for the 

purpose of creating open space

n Relocation of structures outside of the SFHA

n Dry floodproofing of existing non-residential structures and certain residences that are 

listed as historic structures 

n Minor localized flood reduction projects where 50 percent of the structures that directly 

benefit from the mitigation activity are insured by the NFIP

Awards are prioritized to fund projects that create the greatest amount of savings to the NFIP 

based on benefit-cost analyses. A FEMA-approved State/Tribal standard or enhanced hazard 

mitigation plan is required for eligibility. A local mitigation plan is not required.

8.4.6	 Severe Repetitive Loss Program

The SRL program provides funds to assist States, Indian Tribal governments, and local governments that participate in the NFIP to implement projects that reduce or eliminate long-term 

flood risks to certain properties, thus reducing claims paid by the NFIP. To be eligible, a property must qualify under the statutory definition that requires that it: 

n Be a residential property currently insured by the NFIP, and 

n Have incurred flood losses that resulted in either (1) four or more flood insurance claim 

payments that each exceeded $5,000 with at least two of the payments occurring within a 10-

year period, or (2) two or more flood insurance claims payments that cumulatively exceeded 

the value of the property 

The SRL requires a specific consultation process that includes property owner notification and 

information gathering. Applicants are required to follow the specific process to make mitigation offers. SRL property owners who decline a formal offer under the SRL program will be 

subject to an increase in their insurance premiums.

SRL funds are allocated annually to States, Territories, and Indian Tribal governments based 

on the number of severe repetitive loss properties in their respective jurisdictions, with certain “target states” receiving 90 percent of available funds. “Non-target states” compete for the 

remaining 10 percent of available funds. Grants may provide up to 75 percent of a project’s 

8- SI/SD Desk Referenc
MITIGATION PROJECTS 8

eligible costs. The non-Federal cost share may be adjusted to 10 percent if the State has a FEMAapproved mitigation plan that also addresses how the State has and will continue to reduce the 

number of severe repetitive loss properties. Eligible SRL activities include:

n Voluntary acquisition and demolition or relocation of structures and real property for the 

purpose of creating open space.

n Relocation of structures outside of the SFHA.

n Elevation of existing public or private structures to at least the BFE or higher, if required by 

FEMA or if required by State or local regulations.

n Floodproofing measures only for residences that are listed as historic structures.

n Minor localized flood reduction projects where 50 percent of the structures that directly 

benefit from the mitigation activity are insured by the NFIP.

n Mitigation reconstruction, which involves the demolition and rebuilding of structures. It 

is allowed only when traditional elevation methods are not feasible. Grant-eligible costs 

are limited. Applicants should check with their State Hazard Mitigation Office for current 

guidance.

8.5	 Additional Information

FEMA’s mitigation assistance programs provide the opportunity to help communities and property owners address substantially damaged structures. While the programs differ based on their 

statutory requirements, they share a common goal of reducing loss of life and property due to 

natural hazards, including flooding. To learn more, visit FEMA’s websites referenced above or 

contact the appropriate State Hazard Mitigation Officer (Appendix A). 

SI/SD Desk Reference 

SI/SD Desk Reference A

A	 FEMA Regional Offices, NFIP

State Coordinating Agencies,

and State Hazard Mitigation

Offices

FEMA Offices

The addresses and telephone numbers of FEMA Headquarters and the 10 FEMA Regional Offices are listed below. Staff members of the Regional Office for your area can give you more

information about retrofitting, hazard mitigation, and the National Flood Insurance Program.

FEMA HEADQUARTERS

500 C Street, SW.

Washington, DC 20472

(202) 646-2500, (800) 621-FEMA (3362

TTY: (800) 462-7585

REGION I – CT, MA, ME, NH, RI, VT

99 High Street, Sixth Floor

Boston, MA 021

(617) 956-750
A- SI/SD Desk Referenc

A FEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICES

REGION II – NJ, NY, PR, VI

26 Federal Plaza, Suite 133

New York, NY 10278-000

(212) 680-360

REGION III – DC, DE, MD, PA, VA, WV

615 Chestnut Stree

One Independence Mall, Sixth Floor

Philadelphia, PA 19106-44

(215) 931-56

REGION IV – AL, FL, GA, KY, MS, NC, SC, TN

3003 Chamblee Tucker Road

Atlanta, GA 3034

(770) 220-5200

REGION V – IL, IN, MI, MN, OH, WI

536 South Clark Street, Sixth Floor

Chicago, IL 60605-15

(312) 408-550

REGION VI – AR, LA, NM, OK, TX

Federal Regional Center

800 North Loop 288

Denton, TX 76209-3698

(940) 898-5399

REGION VII – IA, KS, MO, NE

9221 Ward Parkway, Suite 30

Kansas City, MO 64114-33

(816) 283-706

REGION VIII – CO, MT, ND, SD, UT, WY

Denver Federal Center, Building 710

P.O. Box 25267

Denver, CO 80255-0267

(303) 235-4800

REGION IX – AZ, CA, HI, NV, American Samoa,

Guam, Commonwealth of the Northern Mariana

Islands, Republic of the Marshall Islands,

Federated States of Micronesia

1111 Broadway, Suite

Oakland, CA 94607-4052

(510) 627-71

REGION X – AK, ID, OR, WA

Federal Regional Center

130 228th Street, SW

Bothell, WA 98021-862

(425) 487-4600

On October 1, 2009, as part of FEMA’s Digital Vision initiative, FEMA discontinued general distribution of paper mapping products, including Flood Insurance Rate Maps (FIRMs) and Flood

Insurance Study (FIS) reports. Electronic copies of FIRMs and FIS reports are available from 

the FEMA Map Service Center online at http://msc.fema.gov. For additional information, call 

the FEMA Map Service Center toll-free at 1-877-336-2627 or contact them by mail at the following address

FEMA Map Service Center

PO Box 103

Jessup, MD 20794-103

NFIP State Coordinating Agencies

ALABAMA

Department of Economic and Community 

Affairs 

Office of Water Resources

401 Adams Avenue, Suite 43

P.O. Box 5690

Montgomery, AL 36103-569

Phone: (334) 353-0853, (877) 252-9283

Fax: (334) 242-0776

http://www.adeca.alabama.gov/water/

ALASKA

Alaska Department of Community and 

Economic Development

550 West 7th Avenue, Suite 177

Anchorage, AK 99501-35

Phone: (907) 269-4500

http://www.commerce.state.ak.us/
SI/SD Desk Reference AFEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICE 

ARIZONA

Arizona Department of Water Resources

3550 North Central Avenue

Phoenix, AZ 85012-21

Phone: (602) 771-865

Fax: (602) 771-86

http://www.azwater.gov/

ARKANSAS

Arkansas Natural Resources Commission

101 East Capitol, Suite 3

Little Rock, AR 72201-382

Phone: (501) 682-396

Fax: (501) 682-39

http://www.anrc.arkansas.gov/

CALIFORNIA

California Department of Water Resources

2825 Watt Avenue, Suite 10

Sacramento, CA 9582

Phone: (916) 574-14

Fax: (916) 574-14

http://www.water.ca.gov/

COLORADO

Colorado Water Conservation Board

1313 Sherman Street, Room 

Denver, CO 80203

Phone: (303) 866-344

Fax: (303) 866-4474

http://cwcb.state.co.us/

CONNECTICUT

Department of Environmental Protection

79 Elm Street

Hartford, CT 0610

Phone: (860) 424-3537

Fax: (860) 424-4075

http://www.ct.gov/dep/

DELAWARE

Department of Natural Resources and 

Environmental Control

89 Kings Highway 

Dover, DE 199

Phone: (302) 739-992

Fax: (302) 739-6724

http://www.dnrec.delaware.gov/

DISTRICT OF COLUMBIA

Department of the Environment

Watershed Protection Division

51 N Street, NE., Room 50

Washington, DC 20002

Phone: (202) 535-2248

Fax: (202) 535-136

http://app.doh.dc.gov/services/

administration_offices/environmental/watershed/watershed_division.shtm

FLORIDA

Division of Emergency Management

2555 Shumard Oak Boulevard

Tallahassee, Florida 32399-210

Phone: (850) 413-98

http://www.floridadisaster.org/

GEORGIA

Department of Natural Resources

7 Martin Luther King, Jr., Drive, Suite 440

Atlanta, GA 30334

Phone: (404) 656-6382

Fax: (404) 656-6383

http://www.gadnr.org/

GUAM

Guam Department of Public Works

Post Office Box 2877

Agana, Guam 9691

Phone: (671) 646-3

Fax: (671) 649-61

http://www.dpw.guam.gov

HAWAII

Hawaii Department of Land and Natural 

Resources

1151 Punchbowl Str

P.O. Box 373

Honolulu, HI 96809

Phone: (808) 587-0267

Fax: (808) 587-0283

http://hawaii.gov/dlnr/
A- SI/SD Desk Referenc

A FEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICES

IDAHO

Department of Water Resources 

322 East Front Street

Boise, ID 83720

Phone: (208) 287-4928

Fax: (208) 287-6700

http://www.idwr.idaho.gov/

ILLINOIS

Illinois Department of Natural Resources

Office of Water Resources

One Natural Resources Way

Springfield, IL 62702-12

Phone: (217) 782-442

Fax: (217) 785-50

http://dnr.state.il.us/OWR/

INDIANA

Indiana Department of Natural Resources

402 W. Washington Street, Room W264

Indianapolis, IN 46204-2748

Phone: (317) 234-1

Fax: (317) 233-457

http://www.state.in.us/dnr/

IOWA

Iowa Department of Natural Resources

Wallace State Office Building

Des Moines, IA 5031

Phone: (515) 281-89

Fax: (515) 281-88

http://www.iowadnr.com/

KANSAS

Department of Agriculture

109 SW 9th Street, 2nd Floo

Topeka, KS 66612-12

Phone: (785) 296-5440

Fax: (785) 296-4835

http://www.ksda.gov/

KENTUCKY

Division of Water

14 Reilly Roa

Frankfort, KY 4060

Phone: (502) 564-341

Fax: (502) 564-9003

http://www.water.ky.gov/

LOUISIANA

Louisiana Department of Transportation 

and Development

Office of Public Works

Floodplain Management Section

1201 Capitol Access Ro

P.O. Box 94245, Capitol Station

Baton Rouge, LA 70804-9245

Phone: (225) 274-4354

Fax: (225) 274-435

http://www.dotd.state.la.us/

MAINE

State Planning Office

184 State Street (street

38 State House Station (mailing)

Augusta, ME 04333-0038

Phone: (207) 287-8063

Fax: (207) 287-6489

http://www.state.me.us/spo/

MARYLAND

Department of the Environment

1800 Washington Boulevard, Suite 43

Baltimore, MD 2123

Phone: (410) 537-377

Fax: (410) 537-37

http://www.mde.state.md.us/

MASSACHUSETTS

Department of Conservation and Recreation

Flood Hazard Management

251 Causeway Street, Suite 70

Boston, MA 021

Phone: (617) 626-14

Fax: (617) 626-13

http://www.mass.gov/dcr/

MICHIGAN

Department of Environmental Quality

525 West Allegan Street

P.O. Box 30473

Lansing, MI 48909-7958

Phone: (517) 373-79

Fax: (517) 373-996

http://www.michigan.gov/deq
SI/SD Desk Reference AFEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICE 

MINNESOTA

Department of Natural Resources

500 LaFayette Road, Box 32

St. Paul, MN 55515-403

Phone: (651) 259-57

Fax: (651) 296-044

http://www.dnr.state.mn.us/

MISSISSIPPI

Emergency Management Agency

Office of Mitigation

1 Mema Driv

P.O. Box 5644

Pearl, MS 39208

Phone: (601) 933-688

Fax: (601) 933-680

http://www.msema.org/

MISSOURI

State Emergency Management Agency

2302 Militia Drive

P.O. Box 1

Jefferson City, MO 6510

Phone: (573) 526-91

Fax: (573) 526-919

http://sema.dps.mo.gov/

MONTANA

Montana Department of Natural Resources 

and Conservation

Floodplain Management Program

1424 9th Avenu

Helena, MT 59620-16

Phone: (406) 444-6654

Fax: (406) 444-0533

http://dnrc.mt.gov/wrd/water_op/floodplain/default.asp

NEBRASKA

Department of Natural Resources

301 Centennial Mall Sout

Lincoln, NE 68509-4876

Phone: (402) 471-393

Fax: (402) 471-290

http://www.dnr.ne.gov/

NEVADA

Division of Water Resources

901 South Stewart Street, Suite 200

Carson City, NV 8970

Phone: (775) 684-2884

Fax: (775) 684-28

http://water.nv.gov/

NEW HAMPSHIRE

Office of Energy and Planning

4 Chenell Drive, 2nd Floor

Concord, NH 0330

Phone: (603) 271-17

Fax: (603) 271-26

http://www.nh.gov/oep/

NEW JERSEY

Department of Environmental Protection

401 East State Stree

P.O. Box 41

Trenton, NJ 08625

Phone: (609) 984-0859

Fax: (609) 984-190

http://www.state.nj.us/dep/

NEW MEXICO

Department of Homeland Security and 

Emergency Management

13 Bataan Boulevar

P.O. Box 162

Santa Fe, NM 87504-162

Phone: (505) 476-961

Fax: (505) 471-969

http://www.nmdhsem.org/

NEW YORK

Department of Environmental Conservation

625 Broadway

Albany, NY 12233-350

Phone: (518) 402-81

Fax: (518) 402-902

http://www.dec.ny.gov/
A- SI/SD Desk Referenc

A FEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICES

NORTH CAROLINA

Department of Crime Control and 

Public Safety

Division of Emergency Management

1812 Tillery Place, Suite 

Raleigh, NC 27604-135

Phone: (919) 715-

Fax: (919) 715-04

http://www.ncem.org/

NORTH DAKOTA

State Water Commission

900 East Boulevard Avenue

Bismark, ND 58505-0850

Phone: (701) 328-489

Fax: (701) 328-374

http://www.swc.state.nd.us/

OHIO

Department of Natural Resources

2045 Morse Road, Building B-2

Columbus, OH 43229

Phone: (614) 265-675

Fax: (614) 265-676

http://www.dnr.state.oh.us/

OKLAHOMA

Water Resources Board

3800 North Classen

Oklahoma City, OK 731

Phone: (918) 581-29

Fax: (405) 530-8900

http://www.owrb.ok.gov/

OREGON

Department of Land Conservation 

Development

635 Capitol Street, NE, Suite 15

Salem, OR 97301-254

Phone: (503) 373-0050

Fax: (503) 375-551

http://www.lcd.state.or.us/

PENNSYLVANIA

Department of Community and 

Economic Development

Commonwealth Keystone Building

400 North Street, 4th Floor

Harrisburg, PA 17120-02

Phone: (717) 720-739

Fax: (717) 783-14

http://www.newpa.com/

PUERTO RICO

Planning Board

Centro Gubernamental Roberto 

Sanchez Vilella

P.O. Box 41119, Minillas Stat

Santurce, PR 00940-90985

Phone: (787) 727-4444

Fax: (787) 268-6858

http://www.jp.gobierno.pr/

RHODE ISLAND

Emergency Management Agency

645 New London Avenue

Cranston, RI 02920

Phone: (401) 462-704

Fax: (401) 944-1

http://www.riema.ri.gov/

SOUTH CAROLINA

Department of Natural Resources

1000 Assembly Street, Suite 345

P.O. Box 16

Columbia, SC 2920

Phone: (803) 734-912

Fax: (803) 734-910

http://www.dnr.sc.gov/

SOUTH DAKOTA

Office of Emergency Management

118 West Capitol Aven

Pierre, SD 5750

Phone: (605) 883-3238

Fax: (605) 773-3580

http://www.oem.sd.gov/
SI/SD Desk Reference AFEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICE 

TENNESSEE

Department of Economic and Community 

Development

Tennessee Tower Building

312 8th Avenue North, 10th Flo

Nashville, TN 37243-0607

Phone: (615) 741-

Fax: (615) 741-06

http://www.state.tn.us/ecd/bizdev_idg.htm

TEXAS

Water Development Board

1700 North Congress Avenu

P.O. Box 132

Austin, TX 78711-3

Phone: (512) 463-350

Fax: (512) 475-205

http://www.twdb.state.tx.us/

UTAH

Department of Public Safety

Division of Comprehensive Emergency 

Management

State Office Building, Room 1

Salt Lake City, UT 841

Phone: (801) 538-333

Fax: (801) 538-377

http://www.cem.utah.gov/

VERMONT

Department of Environmental Conservation

103 South Main Street, Building 10

Waterbury, VT 0567

Phone: (802) 241-15

Fax: (802) 244-51

http://www.anr.state.vt.us/dec/dec.htm

VIRGIN ISLANDS

Department of Planning and Natural 

Resources

C.E. King Airport, Terminal Building 

2nd Floor

St. Thomas, VI 00802

Phone: (340) 774-3320

Fax: (340) 775-5706

http://www.dpnr.gov.vi/

VIRGINIA

Department of Conservation and Historic 

Resources

Division of Dam Safety and Floodplain 

Management 

203 Governor Street, Suite 206

Richmond, VA 2321

Phone: (804) 786-391

Fax: (804) 371-263

http://www.dcr.virginia.gov/

WASHINGTON

Department of Ecology

P.O. Box 47690

Olympia, WA 98504-7600

300 Desmond Drive, SE

Lacey, WA 98503

Phone: (360) 407-6796

Fax: (360) 407-6902

http://www.ecy.wa.gov/

WEST VIRGINIA

Division of Homeland Security and 

Emergency Management

Capitol Building 1, Room EB-8

1900 Kanawha Boulevar

Charleston, WV 25305-0360

Phone: (304) 965-233

Fax: (304) 965-321

http://www.wvdhsem.gov/

WISCONSIN

Department of Natural Resources

101 South Webste

Madison, WI 53702

Phone: (608) 266-8037

Fax: (608) 266-3093

http://dnr.wi.gov/

WYOMING

Office of Homeland Security

Herschler Building, 1st Eas

122 West 25th Stree

Cheyenne, WY 82002

Phone: (307) 777-491

Fax: (307) 635-601

http://wyohomelandsecurity.state.wy.us/main.

aspx
A- SI/SD Desk Referenc

A FEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICES

State Hazard Mitigation Offices

ALABAMA

Alabama Emergency Management Agency

5898 County Road 4

P.O. Drawer 216

Clanton, AL 35046-216

(205) 280-2200

http://www.ema.alabama.gov 

ALASKA

Alaska Department of Homeland Security 

and Emergency Management

P.O. Box 5750

Ft. Richardson, AK 99505-5750

(907) 428-7000

http://www.ak-prepared.com

AMERICAN SAMOA

Emergency Management Coordinating 

Office

P.O. Box 108

Pago Pago, American Samoa 96799

(684) 699-641

ARIZONA

Division of Emergency Management

5636 E. McDowell Road

Phoenix, AZ 85008

(602) 244-0504

http://www.dem.azdema.gov

ARKANSAS

Department of Emergency Management

Bldg. 950

Camp Joseph T. Robinson

North Little Rock, AR 7219

(501) 683-670

http://www.adem.arkansas.gov

CALIFORNIA

California Emergency Management Agency

3650 Shriever Avenue

Mather, CA 95655

(916) 845-85

http://www.calema.ca.gov 

COMMONWEALTH OF THE NORTHERN MARIANA

ISLANDS

Emergency Management Office

P.O. Box 1000

Saipan, Mariana Islands 96950

(670) 322-9529

COLORADO

Division of Emergency Management

9195 East Mineral Avenu

Suite 200

Centennial, CO 801

(720) 852-6600

http://dola.colorado.gov/dem/index.html

CONNECTICUT

Department of Emergency Management 

and Homeland Security

25 Sigourney Street

6th Floor

Hartford, CT 06106-504

(860) 256-0800

http://www.ct.gov/demhs/site/default.asp 

DELAWARE

Delaware Emergency Management Agency

165 Brick Store Landing Roa

Smyrna, DE 1997

(302) 659-3362

http://dema.delaware.gov 

DISTRICT OF COLUMBIA

Homeland Security and Emergency 

Management Agency

2720 Martin Luther King Jr. Avenue, SE

Washington, DC 20032

(202) 727-61

http://dcema.dc.gov/dcema/site/default.

asp

FLORIDA

Florida Division of Emergency Management

2555 Shumard Oak Boulevard

Tallahassee, FL 32399

(850) 413-98

http://www.floridadisaster.org
SI/SD Desk Reference AFEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICE 

GEORGIA

Georgia Emergency Management Agency

935 East Confederate Avenue, SE

P.O. Box 1805

Atlanta, GA 3031

(404) 635-7000

http://www.gema.state.ga.us

GUAM

Guam Homeland Security/Office of Civil 

Defense

221B Chalan Palasy

Agana Heights, Guam 9691

(671) 475-960

HAWAII

Hawaii Department of Emergency 

Management

650 South King Street

Honolulu, HI 9681

(808) 723-8960

http://www.honolulu.gov/dem

IDAHO

Idaho Bureau of Homeland Security 

4040 Guard Street

Building 600

Boise, ID 83705-5004

(208) 422-3040

http://www.bhs.idaho.gov/Pages/Contact.

aspx 

ILLINOIS

Illinois Emergency Management Agency

2200 South Dirksen Parkway

Springfield, IL 62703

(217) 782-270

http://www.state.il.us/iema/

INDIANA

Department of Homeland Security

Indiana Government Center South

302 West Washington Street, Room E-208

Indianapolis, IN 46204

(317) 232-398

http://www.in.gov/dhs

IOWA

Iowa Homeland Security and Emergency 

Management Division

7105 NW 70th Avenu

Camp Dodge, Bldg. W-4

Johnston, IA 501

(515) 725-32

http://www.iowahomelandsecurity.org

KANSAS

Kansas Division of Emergency Management

2800 Southwest Topeka Blvd.

Topeka, KS 66611-1

(785) 274-140

http://www.accesskansas.org/kdem/

KENTUCKY

Kentucky Division of Emergency 

Management

100 Minuteman Parkway Bldg. 1

Frankfort, KY 40601-61

(502) 607-168

http://www.kyem.ky.gov

LOUISIANA

Louisiana Office of Homeland Security 

and Emergency Preparedness

7667 Independence Blvd.

Baton Rouge, LA 70806

(225) 925-7500

http://gohsep.la.gov

MAINE

Maine Emergency Management Agency

72 State House Station

45 Commerce Drive

Augusta, ME 04333

(207) 624-4400

http://www.state.me.us/mema/

MARYLAND

Maryland Emergency Management Agency

5401 Rue Saint Lo Driv

Reisterstown, MD 211

(410) 517-36

http://www.mema.state.md.us/MEMA/index.jsp
A-10 SI/SD Desk Referen

A FEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICES

MASSACHUSETTS

Massachusetts Emergency Management 

Agency

400 Worcester Road

Framingham, MA 01702-539

(508) 820-2000

http://www.state.ma.us/mema

MICHIGAN

Emergency Management and Homeland 

Security Division

Michigan Department of State Police

4000 Collins Road

Lansing, MI 48909-813

(517) 333-504

http://www.michigan.gov/msp

MINNESOTA

Minnesota Homeland Security and 

Emergency Management

444 Cedar Street, Suite 223

St. Paul, MN 55101-62

(651) 201-74

http://www.hsem.state.mn.us/

MISSISSIPPI

Mississippi Emergency Management Agency

P.O. Box 5644

Pearl, MS 39288-514

(601) 933-636

http://www.msema.org

MISSOURI

Missouri State Emergency Management 

Agency

2302 Militia Drive

P.O. Box 1

Jefferson City, MO 6510

(573) 526-910

http://www.sema.dps.mo.gov/semapage.htm

MONTANA

Montana Disaster and Emergency Services 

P.O. Box 4789

Ft. Harrison, MT 59636-4789

(406) 324-3000

http://www.dma.mt.gov/des

NEBRASKA

Nebraska Emergency Management Agency

1300 Military Roa

Lincoln, NE 68508-109

(402) 471-74

http://www.nema.ne.gov

NEVADA

Nevada Division of Emergency Management

2478 Fairview Drive

Carson City, NV 8970

(775) 687-0300

http://www.dem.state.nv.us

NEW HAMPSHIRE

New Hampshire Department of Safety

Homeland Security and Emergency 

Management

33 Hazen Street 

Concord, NH 03305

(603) 271-22

http://www.nh.gov/safety/divisions/shem 

NEW JERSEY

New Jersey Office of Emergency 

Management

P.O. Box 7068 

West Trenton, NJ 08628-0068

(609) 538-6050

http://www.state.nj.us/njoem/

NEW MEXICO

New Mexico Department of Homeland 

Security and Emergency Management

P.O. Box 27111-87

13 Bataan Blvd

Santa Fe, NM 87504

(505) 476-9600

http://www.nmdhsem.org

NEW YORK

New York State Emergency Management 

Office

1220 Washington Avenue, Suite 

Building # 22

Albany, NY 12226-22

(518) 292-23

http://www.semo.state.ny.us/
SI/SD Desk Reference A-1FEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFI 

NORTH CAROLINA

North Carolina Division of Emergency 

Management

4713 Mail Service Cente

Raleigh, NC 27699-471

(919) 733-386

http://www.ncem.org

NORTH DAKOTA

North Dakota Emergency Management

P.O. Box 55

Fraine Barrecks Lane, Bldg. 35

Bismarck, ND 59506-55

(701) 328-8

http://www.nd.gov/des

OHIO

Ohio Emergency Management Agency

2855 West Dublin-Granville Road

Columbus, OH 43235-2206

(614) 889-71

http: //ema.ohio.gov

OKLAHOMA

Oklahoma Emergency Management Agency

2401 Lincoln Blvd

Suite C5

Oklahoma City, OK 7310

(405) 521-24

http://www.ok.gov/OEM

OREGON

Office of Emergency Management

3225 State Street

Salem, OR 97309-5062

(503) 378-29

http://www.oregon.gov/OMD/OEM/index.

shtml

PENNSYLVANIA

Pennsylvania Emergency Management 

Agency

2605 Interstate Drive

P.O. Box 322

Harrisburg, PA 17110-9

(717) 651-2

http://www.pema.state.pa.us

PUERTO RICO

Puerto Rico Emergency Management

P.O. Box 966597

San Juan, PR 00906-6597

(787) 724-0124

http://www.gobierno.pr/AEMEAD/Inicio

RHODE ISLAND

Rhode Island Emergency Management 

Agency

645 New London Avenue

Cranston, RI 02920

(401) 946-999

http://www.riema.ri.gov

SOUTH CAROLINA

South Carolina Emergency Management 

Division

2779 Fish Hatchery Road

West Columbia, SC 2917

(803) 37-8500

http://www.scemd.org

SOUTH DAKOTA

South Dakota Division of Emergency 

Management

118 West Capitol Aven

Pierre, SD 5750

(605) 773-317

http://www.oem.sd.gov

TENNESSEE

Tennessee Emergency Management Agency

3041 Sidco Driv

Nashville, Tennessee 37204

(615) 741-0

http://www.tnema.org

TEXAS

Texas Division of Emergency Management 

P.O. Box 4087

Austin, TX 78773-0220

(512) 424-21

http://www.txdps.state.tx.us/dem/pages/index.htm
A-12 SI/SD Desk Referen

A FEMA REGIONAL OFFICES, NFIP STATE COORDINATING AGENCIES, AND STATE HAZARD MITIGATION OFFICES

UTAH

Utah Division of Emergency Services 

and Homeland Security

State Office Building, Room 1

Salt Lake City, UT 84114-

(801) 538-340

http://www.des.utah.gov

VERMONT

Vermont Emergency Management Agency

Department of Public Safety

Waterbury State Complex

103 S. Main Stree

Waterbury, VT 05671-2

(802) 242-872

http://www.dps.state.vt.us/

VIRGINIA

Department of Emergency Management

10501 Trade Cou

Richmond, VA 23236-371

(804) 897-6500

http://www.vaemergency.com/index.cfm

VIRGIN ISLANDS

Virgin Islands Territorial Emergency 

Management

2-C Contant, A-Q Bldg.

St. Thomas, VI 00820

(340) 774-2244 

WASHINGTON

Washington Military Department

Emergency Management Division

Bldg. 20, MS TA-20

Camp Murray, WA 98430-512

(253) 512-700

http://www.emd.wa.gov/

WEST VIRGINIA

West Virginia Division of Homeland Security 

and Emergency Services

Building 1, Room EB-8

1900 Kanawha Blvd., Eas

Charleston, WV 25305-0360

(304) 558-5380

http://www.wvdhsem.gov

WISCONSIN

Wisconsin Emergency Management

2400 Wright Street

Madison, WI 53707-7865

(608) 242-3232

http://emergencymanagement.wi.gov/

WYOMING

Wyoming Department of Homeland Security

122 West 25th Stree

Herschler Building, 1st Floor Eas

Cheyenne, WY 82002

(307) 777-4663

http://wyohomelandsecurity.state.wy.us/

main.aspx
SI/SD Desk Reference B

B References

FEMA publications are available for download free of charge at http://www.fema.gov/library. 

Publications can also be obtained in hardcopy format from the FEMA Distribution Center by 

submitting an order by regular mail, phone, or fax, Monday through Friday, between 8 a.m. and 

5 p.m. Eastern Standard Time. Please provide the FEMA publication number, title, and quantity 

of each publication requested, along with your name, address, zip code, and daytime telephone 

number. 

FEMA Distribution Center

P.O. Box 430

Buckeystown, MD 217

1-800-480-252

240-699-0525 (fax)

ASCE/SEI 7-05, Minimum Design Loads for Buildings and Other Structures. Reston, VA: American 

Society of Civil Engineers/Structural Engineering Institute, 2005. 

http://cedb.asce.org/cgi/WWWdisplay.cgi?0500267

ASCE/SEI 24-05, Flood Resistant Design and Construction. Reston, VA: American Society of Civil 

Engineers/Structural Engineering Institute, 2005. 

http://cedb.asce.org/cgi/WWWdisplay.cgi?0500268

ATC 45, Field Manual: Safety Evaluation of Buildings after Windstorms and Floods. Redwood City, 

CA: Applied Technology Council, 2004. 

http://www.atcouncil.org/pdfs/ATC45toc.pdf

FEMA, CRS Credit for Higher Regulatory Standards. Washington, DC: Federal Emergency Management Agency, 2006. 

http://training.fema.gov/EMIWeb/CRS/2006%20Model%20430%20Higher%20Standards.pdf

FEMA 55, Coastal Construction Manual (3rd Edition). Washington, DC: Federal Emergency 

Management Agency, 2000.

http://www.fema.gov/rebuild/mat/fema55.shtm

FEMA P-85, Protecting Manufactured Homes from Floods and Other Hazards: A Multi-Hazard Foundation and Installation Guide, Second Edition. Washington, DC: Federal Emergency Management 

Agency, 2009. 

http://www.fema.gov/library/viewRecord.do?id=157

FEMA 213, Answers to Questions about Substantially Damaged Buildings. Washington, DC: Federal

Emergency Management Agency, 199

http://www.fema.gov/library/viewRecord.do?id=163
B- SI/SD Desk Referenc

B REFERENCES

FEMA 234, Repairing Your Flooded Home. Washington, DC: Federal Emergency Management 

Agency, 1992.

http://www.fema.gov/library/viewRecord.do?id=14

FEMA 259, Engineering Principles and Practices of Retrofitting Flood-Prone Residential Structures. 

Washington, DC: Federal Emergency Management Agency, 2001

http://www.fema.gov/library/viewRecord.do?id=164

FEMA 301, Increased Cost of Compliance Coverage: Guidance for State and Local Officials. Washington, DC: Federal Emergency Management Agency, 2003

http://www.fema.gov/library/viewRecord.do?id=153

FEMA P-312, Homeowner’s Guide to Retrofitting: Six Ways to Protect Your Home from Flooding, Second

Edition. Washington, DC: Federal Emergency Management Agency, 2009. 

http://www.fema.gov/library/viewRecord.do?id=142

FEMA 347, Above the Flood: Elevating Your Floodprone House. Washington, DC: Federal Emergency Management Agency, 2000.

http://www.fema.gov/library/viewRecord.do?id=142

FEMA 348, Protecting Building Utilities from Flood Damage: Principles and Practices for the Design and 

Construction of Flood Resistant Building Utility Systems. Washington, DC: Federal Emergency Management Agency, 1999

http://www.fema.gov/library/viewRecord.do?id=175

FEMA F-084, Answers to Questions about the National Flood Insurance Program. Washington, DC: 

Federal Emergency Management Agency, 2006. 

http://www.fema.gov/business/nfip/qanda.shtm

FEMA P-467-2, Floodplain Management Bulletin: Historic Structures. Washington, DC: Federal 

Emergency Management Agency, 2008.

http://www.fema.gov/library/viewRecord.do?id=3282

FEMA 480, NFIP Floodplain Management Requirements: A Study Guide and Desk Reference. Washington, DC: Federal Emergency Management Agency, 2005.

http://www.fema.gov/library/viewRecord.do?id=144

FEMA 497, National Flood Mitigation Data Collection Tool. Washington, DC: Federal Emergency 

Management Agency, 2008.

http://www.fema.gov/library/viewRecord.do?id=144

FEMA 499, Home Builder’s Guide to Coastal Construction: Technical Fact Sheets. Washington, DC: 

Federal Emergency Management Agency, 2005.

http://www.fema.gov/library/viewRecord.do?id=213
SI/SD Desk Reference BREFERENCE 

FEMA 511, Reducing Damage from Localized Flooding: A Guide for Communities. Washington, DC

Federal Emergency Management Agency, 2005.

http://www.fema.gov/library/viewRecord.do?id=144

FEMA 551, Selecting Appropriate Mitigation Measures for Floodprone Structures. Washington, DC:

Federal Emergency Management Agency, 2007.

http://www.fema.gov/library/viewRecord.do?id=2737

FEMA F-663, Increased Cost of Compliance Brochure. Washington, DC: Federal Emergency Management Agency, 2007.

http://www.fema.gov/library/viewRecord.do?id=3009

FEMA P-784 CD. FEMA Substantial Damage Estimator. Washington, DC: Federal Emergency 

Management Agency, 2010

FEMA Form 81-31, Elevation Certificate. Washington, DC: Federal Emergency Managemen

Agency, 2009.

http://www.fema.gov/pdf/nfip/elvcert.pdf 

FEMA Form 81-65, Floodproofing Certificate. Washington, DC: Federal Emergency Management

Agency, 2009. 

http://www.fema.gov/pdf/fhm/ff81-65.pd

FEMA, NFIP Technical Bulletin Series. Washington, DC: National Flood Insurance Program. 

http://www.fema.gov/plan/prevent/floodplain/techbul.shtm 

FEMA Technical Bulletin 0: User’s Guide to Technical Bulletins. 2009. 

FEMA Technical Bulletin 1: Openings in Foundation Walls and Walls of Enclosures Below Buildings Located in Special Flood Hazard Areas. 2008

FEMA Technical Bulletin 2: Flood Damage-Resistant Materials Requirements for Buildings Located 

in Special Flood Hazard Areas. 2008.

FEMA FIA-TB-3: Non-Residential Floodproofing – Requirements and Certification for Buildings Located in Special Flood Hazard Areas. 1993

FEMA FIA-TB-4: Elevator Installation for Buildings Located in Special Flood Hazard Areas. 1993

FEMA Technical Bulletin 5: Free-of-Obstruction Requirements for Buildings Located in Coastal High 

Hazard Areas. 2008.

FEMA FIA-TB-6: Below-Grade Parking Requirements for Buildings Located in Special Flood Hazard 

Areas. 1993.
B- SI/SD Desk Referenc

B REFERENCES

FEMA FIA-TB-7: Wet Floodproofing Requirements for Structures Located in Special Flood Hazard 

Areas. 1993.

FEMA FIA-TB-8: Corrosion Protection for Metal Connectors in Coastal Areas for Structures Located 

in Special Flood Hazard Areas. 1996

FEMA Technical Bulletin 9: Design and Construction Guidance for Breakaway Walls Below Elevated Coastal Buildings. 2008.

FEMA FIA-TB-10: Ensuring that Structures Built on Fill in or Near Special Flood Hazard Areas are

Reasonably Safe From Flooding. 2001

FEMA FIA-TB-11: Crawlspace Construction for Buildings Located in Special Flood Hazard Area

(NFIP Interim Guidance). 2001

FEMA FIA-15, NFIP Community Rating System: Coordinator’s Manual. Washington, DC: Federal

Emergency Management Agency, 2002.

http://www.fema.gov/library/viewRecord.do?id=17

FEMA 9-0372, Reducing Flood Losses Through the International Codes®: Meeting the Requirements of 

the National Flood Insurance Program. Washington, DC: International Code Council, Inc., 2007.

http://www.fema.gov/library/viewRecord.do?id=2094

IBC, International Building Code®. Washington, DC: International Code Council, Inc., 2009.

http://www.icesafe.org/Store/pages/product.aspx?id=3000x09

IEBC, International Existing Building Code®. Washington, DC: International Code Council, Inc., 

2009.

http://www.bookmarki.com/2009-International-Existing-Building-Code-Softp/9781580017374.h

IRC, International Residential Code®. Washington, DC: International Code Council, Inc., 2009.

http://www.internationalcodes.net/2009-international-residential-codes.shtml

National Flood Insurance Program, Program Description. Washington, DC: Federal Emergency 

Management Agency, 2002. 

http://www.fema.gov/library/viewRecord.do?id=148

The Appraisal Foundation, Uniform Standards of Professional Appraisal Practice (USPAP), 2010.

http://www.appraisalfoundation.org

U.S. Government Printing Office. Title 44, Code of Federal Regulations, Emergency Management and Assistance (Parts 59 and 60; Part 210).

http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?sid=68742042ab4d62552371ef4fa697f404&c=e

fr&tpl=/ecfrbrowse/Title44/44tab_02.tpl
SI/SD Desk Reference C

C Glossary and Acronyms 

Glossary 

Key terms and definitions are addressed in Chapter 3. The following are additional terms used 

in this Desk Reference.

A

Accessory structure – A structure that is on the same parcel of property as a principal structure, 

the use of which is incidental to the use of the principal structure.

Agricultural structure – A structure used exclusively for agricultural purposes such as storage of 

farm machinery and equipment, grain bins and silos, corn cribs, and general purposes barns for 

feeding and raising livestock. Homes located on farms are not agricultural structures.

B

Base flood – The flood having a 1-percent chance of being equaled or exceeded in any given

year, commonly referred to as the “100-year flood.” The base flood is the national standard used

by the NFIP and all Federal agencies for the purposes of requiring the purchase of flood insurance and regulating new development. 

Base flood elevation (BFE) – The elevation of the base (1-percent annual chance or 100-year

flood compared to a specified datum, usually the National Geodetic Vertical Datum of 1929, or

the North American Vertical Datum of 1988

Basement – Any area of a building having its floor subgrade (below ground level) on all sides. 

Breakaway wall – A wall that is not part of the structural support of the building and is intended 

through its design and construction to collapse under specified lateral loading forces, without 

causing damage to the elevated portion of the building or supporting foundation system. 

D

Determination, SI/SD – The result of comparing the costs of a proposed improvement (or costs 

to repair substantial damage) to the market value of a structure for the purposes of determining whether the resulting ratio equals or exceeds a certain percentage (50 percent in the NFIP 

minimum requirements). 

E

Elevation Certificate – FEMA Form 81-31, a form developed by FEMA to collect surveyed elevations and other information about a building that is necessary to obtain flood insurance

The Elevation Certificate and instructions are available online at http://www.fema.gov/library/

viewRecord.do?id=1383.
C- SI/SD Desk Referenc

c glossary and acronyms

Enclosure or enclosed area – Areas created by a crawlspace or solid walls that fully enclose areas 

below elevated buildings that are below the BFE.

F

Federal Emergency Management Agency (FEMA) – The Federal agency that, in addition to carrying out other activities, administers the National Flood Insur¬ance Program. 

Flood Insurance Rate Map (FIRM) – The official map of a community on which FEMA has delineated both the SFHAs and the risk premium zones applicable to the community.

Flood opening – An opening in a foundation or enclosure wall that allows automatic entry and 

exit of floodwaters (see FEMA Technical Bulletin  for descriptions of “non-engineered opening” and “engineered opening”).

Floodway – The channel of a river or other watercourse and the adjacent land areas that must 

be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.

Floodproofing – Any combination of structural and non-structural additions, changes, or adjustments to structures that reduce or eliminate flood damage to real estate or improved real 

property, water and sanitary facilities, structures, and their contents.

Floodproofing Certificate – FEMA Form 81-65, a form developed by FEMA that is to be completed, signed and sealed by a licensed professional engineer or licensed architect to certify that

the design of the floodproofing and the proposed methods of construction are in accordance 

with the requirements. The Floodproofing Certificate is available online at http://www.fema.gov/

library/viewRecord.do?id=1600

H

Historic structure – Any structure that is:

(a) Listed individually in the National Register of Historic Places (a listing maintained by the 

Department of Interior) or preliminarily determined by the Secretary of the Interior as 

meeting the requirements for individual listing on the National Register;

(b) Certified or preliminarily determined by the Secretary of the Interior as contributing to 

the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;

(c) Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or

(d) Individually listed on a local inventory of historic places in communities with historic 

preservation programs that have been certified either:
SI/SD Desk Reference Cglossary and acronym

(1) By an approved state program as determined by the Secretary of the Interior o

(2) Directly by the Secretary of the Interior in states without approved programs.

Hydrodynamic load – The load imposed on an object, such as a foundation element or enclosure wall, by water flowing against and around it. 

Hydrostatic load – The load imposed on an object, such as an enclosure wall, by a standing mass 

of water. 

N

New construction – Structures for which the “start of construction” commenced on or after the 

effective date of a floodplain management regulation adopted by a community and includes 

any subsequent improvements to such structures.

P

Post-FIRM – A building for which construction or substantial improvement occurred after December 31, 1974, or on or after the effective date of an initial Flood Insurance Rate Map (FIRM)

whichever is later.

Pre-FIRM – A building for which construction or substantial improvement occurred on or before December 31, 1974, or before the effective date of an initial FIR

R

Registered Design Professional – An individual who is registered or licensed to practice their 

respective design profession as defined by the statutory requirements of the professional registration laws of the State or jurisdiction in which the project is to be constructed.

S

Special Flood Hazard Area (SFHA) – An area delineated on a Flood Insurance Rate Map as being subject to inundation by the base flood and designated as Zone A, AE, A1-A30, AR, AO, AH,

A99, V, VE, or V1-V30.

Substantial damage – Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the 

market value of the structure before the damage occurred.

Substantial improvement – Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the 

structure before the “start of construction'' of the improvement. This term includes structures 

that have incurred “substantial damage,” regardless of the actual repair work performed. The 

term does not, however, include either:
C- SI/SD Desk Referenc

c glossary and acronyms

(1) Any project for improvement of a structure to correct existing violations of State or local health, sanitary, or safety code specifications which have been identified by the local

code enforcement official and which are the minimum necessary to assure safe living 

conditions or

(2) Any alteration of a “historic structure,” provided that the alteration will not preclude the 

structure's continued designation as a “historic structure.”

V

Violation – The failure of a structure or other development to be fully compliant with the community’s floodplain management regulations. 
SI/SD Desk Reference Cglossary and acronym

Acronyms

A 

ACV actual cash value

ADA Americans with Disabilities Act

ASCE American Society of Civil Engineers, Inc.

ASFPM Association of State Floodplain Managers, Inc.

ATC Applied Technology Council

B

BFE base flood elevation

C

CBRS Coastal Barrier Resource System

CFR Code of Federal Regulations

CRS Community Rating System 

D

DHS Department of Homeland Security

F

FEMA Federal Emergency Management Agency

FHBM Flood Hazard Boundary Map

FIA Federal Insurance Administration

FIRM Flood Insurance Rate Map

FIS Flood Insurance Study

FMA Flood Mitigation Assistance (grant program)
C- SI/SD Desk Referenc

c glossary and acronyms

G

GIS geographic information system

GPS global positioning system

H

HMGP Hazard Mitigation Grant Program

HVAC Heating, ventilation, and air conditioning

I

IBC International Building Code®

I-Codes The family of codes published by the International Code Council, Inc.

ICC Increased Cost of Compliance (NFIP flood insurance coverage)

ICC International Code Council, Inc.

IEBC International Existing Building Code®

IRC International Residential Code®

N

NFIP National Flood Insurance Program

O

OPA Otherwise Protected Area

P

PDA Preliminary Damage Assessment

PDM Pre-Disaster Mitigation (grant program)
SI/SD Desk Reference Cglossary and acronym

R

RCV replacement cost value

RFC Repetitive Flood Claims (grant program)

RLP Repetitive Loss Property

S

SDE Substantial Damage Estimator

SEI Structural Engineering Institute

SFHA Special Flood Hazard Area

SI/SD substantial improvement/substantial damage

SRL Severe Repetitive Loss (grant program)

SI/SD Desk Reference D

D Sample Notices to Property 

Owners, Sample Affidavits, and 

Other Material 

These samples are offered to illustrate specific points in the Desk Reference. States and communities should examine them carefully before use. 

n Sample Substantial Improvement/Damage Notice to Property Owners (see Sections 5.5.

and 5.6.2.) 

n Substantial Improvement Worksheet for Floodplain Construction (for additions, 

rehabilitations, improvements or damage repairs; see Section 6.4)

n Adjuster Preliminary Damage Assessment (FEMA Form 81-109; see Section 7.4.

Sample Notice for Property Owners, Contractors, and Design 

Professionals 

[This example is based on the NFIP minimum requirements.]

TO: Property Owners, Contractors, and Design Professionals 

FROM: Local Official

SUBJECT: Notice for Work on Existing Buildings in Special Flood Hazard Areas

Substantial Improvement / Substantial Damage Worksheets 

The Community’s floodplain management regulations and codes specify that all new buildings 

to be constructed in Special Flood Hazard Areas (SFHAs) (regulated floodplains) are required 

to have their lowest floors elevated to or above the base flood elevation (BFE). The regulations 

also specify that substantial improvement of existing buildings (remodeling, rehabilitation, improvement, or addition) or buildings that have sustained substantial damage must be brought 

into compliance with the requirements for new construction. Please note that a building may be 

substantially damaged by any cause, including fire, flood, high wind, seismic activity, land movement, or neglect. It is important to note that all costs to repair a substantially damaged building 

to its pre-damage condition must be identified.

There are several aspects that must be addressed to achieve compliance with the floodplain 

management requirements. The requirements depend on several factors, including the flood 

zone at your property. The most significant compliance requirement is that the lowest floor, as 

defined in the regulations/code, must be elevated to or above the BFE. Please plan to meet with 

this department to review your proposed project, to go over the requirements, and to discuss 

how to bring your building into compliance.

Our regulations define these terms: 

Substantial damage means damage of any origin sustained by a structure whereby the 

cost of restoring the structure to its before damaged condition would equal or exceed 50 

percent of the market value of the structure before the damage occurred.

Substantial improvement means any reconstruction, rehabilitation, addition, or other 

improvement of a structure, the cost of which equals or exceeds 50 percent of the market 

value of the structure before the ”start of construction’’ of the improvement. This term 

includes structures that have incurred “substantial damage," regardless of the actual repair work performed. The term does not, however, include either:

(1) Any project for improvement of a structure to correct existing violations of

State or local health, sanitary, or safety code specifications that have been identified by the local code enforcement official and that are the minimum necessary 

to assure safe living conditions or

Sample Notice for Property Owners, Contractors, andDesi
(2) Any alteration of a “historic structure," provided that the alteration will not 

preclude the structure’s continued designation as a “historic structure."

To make the substantial improvement determination or the substantial damage determination, 

we compare the cost of the proposed improvement or repairs to the market value of the building (excluding land, accessory structures, and landscaping). If the resulting ratio equals or 

exceeds 50 percent, the existing building must be brought into compliance with the fl oodplain 

management requirements for new buildings. 

Please note:

n You must provide an estimate of the cost to perform the proposed improvements or repairs. 

If your building has been damaged, the cost estimate must include all work required to 

repair the building to its pre-damage condition. The cost estimate must include all labor 

and materials. If the work will be done by a contractor, the contractor’s overhead and profi t 

must be included. If the work will be done by the owner or volunteers, market rates must be 

used to estimate the cost of materials and the value of labor. Attached to this notice is a list 

of costs that must be included and costs that are excluded. After we review the cost estimate, 

we may require that it be broken down to show all materials and labor estimates. 

n You must provide a market value appraisal of the building that is prepared by a professional 

appraiser according to standard practices of the profession. We will review the appraisal 

to determine that it accurately describes your building and does not include the value of 

the land, accessory buildings, and landscaping. Alternatively, we will use the tax assessment 

value of your building as the estimate of the market value of the building before the work is 

performed. 

If you have any questions regarding this information, please contact ______________________

Attachments:

Requirements for Applications for Permits for Substantial Improvements and Repair of 

Substantial Damage

Costs for Substantial Improvements and Repair of Substantial Damage

Owner’s Affi davit

Contractor’s Affi davit

Cost of Improvement or Cost to Repair to Pre-Damage Condition

Market Value of Building

≥ 50%

2 of 7 Sample notIce foR pRopeRty owneRS, contRactoRS, anD DeSIgn pRofeSSIonalS
Requirements for Applications for Permits for Substantial Improvements and 

Repair of Substantial Damage

Please contact _____________ if you have questions about the substantial improvement and substantial damage requirements. Your building may have to be brought into compliance with the 

floodplain management requirements for new construction. 

Applications for permits to work on existing buildings that are located in Special Flood Hazard 

Areas must include the following:

n Current photographs of the exterior (front, rear, sides)

n If your building has been damaged, include photographs of the interior and exterior; 

provide pre-damage photos of the exterior, if available 

n Detailed description of the proposed improvement (rehabilitation, remodeling, addition, 

etc.) or repairs

n Cost estimate of the proposed improvement or the cost estimate to repair the damaged 

building to its before-damage condition

n Elevation certificate or elevation survey

n You may submit a market value appraisal prepared by a licensed professional appraiser or we 

will use the tax assessment value of the building

n Owner’s affidavit (signed and dated)

n Contractor’s affidavit (signed and dated)

Sample Notice for Property Owners, Contractors, and Design
Costs for Substantial Improvements and Repair of Substantial Damage

Included Costs 

Items that must be included in the costs of improvement or costs to repair are those that are 

directly associated with the building. The following list of costs that must be included is not intended to be exhaustive, but characterizes the types of costs that must be included:

n Materials and labor, including the estimated 

value of donated or discounted materials 

and owner or volunteered labor 

n Site preparation related to the improvement 

or repair (foundation excavation, filling in 

basements)

n Demolition and construction debris disposal

n Labor and other costs associated with 

demolishing, moving, or altering 

building components to accommodate 

improvements, additions, and making 

repairs

n Costs associated with complying with any 

other regulation or code requirement that 

is triggered by the work, including costs 

to comply with the requirements of the 

Americans with Disabilities Act (ADA)

n Costs associated with elevating a structure to 

an elevation that is lower than the BFE

n Construction management and supervision

n Contractor’s overhead and profit

n Sales taxes on materials

n Structural elements and exterior finishes, 

including:

n Foundations (e.g., spread or continuous foundation footings, perimeter walls, 

chainwalls, pilings, columns, posts, etc.)

n Monolithic or other types of concrete 

slabs

n Bearing walls, tie beams, trusses

n Joists, beams, subflooring, framing, 

ceilings

n Interior non-bearing walls

n Exterior finishes (e.g., brick, stucco, siding, painting, and trim)

n Structural elements and exterior finishes 

(cont.):

n Windows and exterior doors 

n Roofing, gutters, and downspouts

n Hardware 

n Attached decks and porches

n Interior finish elements, including:

n Floor finishes (e.g., hardwood, ceramic, vinyl, linoleum, stone, and 

wall-to-wall carpet over subflooring)

n Bathroom tiling and fixtures

n Wall finishes (e.g., drywall, paint, stucco, plaster, paneling, and marble)

n Built-in cabinets (e.g., kitchen, utility, 

entertainment, storage, and bathroom)

n Interior doors

n Interior finish carpentry

n Built-in bookcases and furniture

n Hardware

n Insulation

n Utility and service equipment, including:

n HVAC equipment

n Plumbing fixtures and piping

n Electrical wiring, outlets, and switches

n Light fixtures and ceiling fans

n Security systems

n Built-in appliances

n Central vacuum systems

n Water filtration, conditioning, and recirculation systems

4 of 7 Sample Notice for Property Owners, Contractors, an
Excluded Costs 

Items that can be excluded are those that are not directly associated with the building. The following list characterizes the types of costs that may be excluded: 

n Clean-up and trash removal 

n Costs to temporarily stabilize a building so 

that it is safe to enter to evaluate required 

repairs

n Costs to obtain or prepare plans and 

specifications

n Land survey costs

n Permit fees and inspection fees 

n Carpeting and recarpeting installed over 

finished flooring such as wood or tiling

n Outside improvements, including 

landscaping, irrigation, sidewalks, driveways, 

fences, yard lights, swimming pools, 

pool enclosures, and detached accessory 

structures (e.g., garages, sheds, and gazebos) 

n Costs required for the minimum necessary 

work to correct existing violations of health, 

safety, and sanitary codes

n Plug-in appliances such as washing 

machines, dryers, and stoves 

Sample Notice for Property Owners, Contractors, and Desig
Owner’s Affidavit: Substantial Improvement or Repair of Substantial Damage

Property Address:

Parcel ID Number: 

Owner’s Name:

Owner’s Address/Phone:

Contractor: 

Contractor’s License Number: 

Date of Contractor’s Estimate: 

I hereby attest that the description included in the permit application for the work on the existing building that is located at the property identified above is all of the work that will be done, 

including all improvements, rehabilitation, remodeling, repairs, additions, and any other form 

of improvement. I further attest that I requested the above-identified contractor to prepare 

a cost estimate for all of the work, including the contractor’s overhead and profit. I acknowledge that if, during the course of construction, I decide to add more work or to modify the 

work described, that the [insert community] will re-evaluate its comparison of the cost of work 

to the market value of the building to determine if the work is substantial improvement. Such 

re-evaluation may require revision of the permit and may subject the property to additional requirements.

I also understand that I am subject to enforcement action and/or fines if inspection of the property reveals that I have made or authorized repairs or improvements that were not included in 

the description of work and the cost estimate for that work that were the basis for issuance of a 

permit.

Owner’s Signature: 

Date:

Notarized: 

6 of 7 Sample Notice for Property Owners, Contractors, an
Contractor’s Affidavit: Substantial Improvement or Repair of Substantial Damage

Property Address:

Parcel ID Number: 

Owner’s Name:

Owner’s Address/Phone:

Contractor: 

Contractor’s License Number: 

Date of Contractor’s Estimate: 

I hereby attest that I have personally inspected the building located at the above-referenced 

address and discussed the nature and extent of the work requested by the owner, including all 

improvements, rehabilitation, remodeling, repairs, additions, and any other form of improvement. 

At the request of the owner, I have prepared a cost estimate for all of the improvement work 

requested by the owner and the cost estimate includes, at a minimum, the cost elements identified by the [community] that are appropriate for the nature of the work. If the work is repair of 

damage, I have prepared a cost estimate to repair the building to its pre-damage condition. I 

acknowledge that if, during the course of construction, the owner requests more work or modification of the work described in the application, that a revised cost estimate must be provided 

to the [insert community], which will re-evaluate its comparison of the cost of work to the market 

value of the building to determine if the work is substantial improvement. Such re-evaluation 

may require revision of the permit and may subject the property to additional requirements.

I also understand that I am subject to enforcement action and/or fines if inspection of the property reveals that I have made or authorized repairs or improvements that were not included in 

the description of work and the cost estimate for that work that were the basis for issuance of a 

permit.

Owner’s Signature: 

Date:

Notarized: 

Sample Notice for Property Owners, Contractors, and Desig
Substantial Improvement Worksheet for Floodplain Construction

(for reconstruction, rehabilitation, addition, or other improvements, and repair of damage from any cause)


E Sample Letters of Determination

n	 Letter to Notify Property Owners of a Determination That Work Constitutes Substantial

Improvement

n	 Letter to Notify Property Owners of a Determination That Work Constitutes Repair of

Substantial Damage

n	 Letter to Notify Property Owners of a Determination That Work Does NOT Constitute

Repair of Substantial Damage

SI/SD Desk Reference E

Sample Letter to Notify Property Owners of a Determination That 

Work Constitutes Substantial Improvement

Notice of Substantial Improvement Determination (Residential)

Dear Property Owner:

We have reviewed your recent application for a permit to [describe proposed improvement/addition] your existing home that is located in a mapped Special Flood Hazard Area. As required

by our floodplain management regulations and/or building code, we have determined that

the proposed work constitutes substantial improvement of the building. This determination

is based on a comparison of the cost estimate of the proposed work to the market value of the

building (excluding land value). When the costs equal or exceed 50 percent of the market value

of the building, the work is substantial improvement.

As a result of this determination, you are required to bring the building into compliance with

the flood damage-resistant provisions of the regulations and/or code [cite pertinent sections].

We would be pleased to meet with you and your designated representative (architect/builder)

to discuss how to bring your home into compliance. There are several aspects that must be addressed to achieve compliance. The most significant requirement is that the lowest floor, as

defined in the regulations/code, must be elevated to or above the base flood elevation (BFE)

[or the elevation specified in the regulations/code]. You may wish to contact your insurance

agent to understand how raising the lowest floor higher than the minimum required elevation

can reduce NFIP flood insurance premiums.

Please resubmit your permit application along with plans and specifications that incorporate

compliance measures. Construction activities that are undertaken without a proper permit are

violations and may result in citations, fines, or other legal action.
Sample Letter to Notify Property Owners of a Determination That 

Work Constitutes Repair of Substantial Damage

Notice of Substantial Damage Determination (Residential)

Dear Property Owner:

We have reviewed your recent application for a permit to repair your existing home that was

damaged by [insert cause of damage]. The building is located in a mapped Special Flood Hazard Area. As required by our floodplain management regulations and/or building code, we

have determined that the building has been substantially damaged. This determination is based

on a comparison of the cost estimate of the work required to restore the building to its predamage condition to the market value of the building (excluding land value). When the cost

to repair equals or exceeds 50 percent of the market value of the building, the work is repair of

substantial damage.

As a result of this determination, you are required to bring the building into compliance with

the flood damage-resistant provisions of the regulations and/or code [cite pertinent sections].

We would be pleased to meet with you and your designated representative (architect/builder)

to discuss how to bring your home into compliance. There are several aspects that must be addressed to achieve compliance. The most significant requirement is that the lowest floor, as

defined in the regulations/code, must be elevated to or above the base flood elevation (BFE)

[or the elevation specified in the regulations/code]. You may wish to contact your insurance

agent to understand how raising the lowest floor higher than the minimum required elevation

can reduce NFIP flood insurance premiums.

If the damage was caused by flooding and if you have a flood insurance policy from the National Flood Insurance Program, you should contact your adjuster to discuss the Increased Cost of

Compliance (ICC) coverage. This coverage may provide a claim payment to help pay for work

required to bring your home into compliance. Your adjuster can explain that the ICC claim may

also be used to pay certain costs associated with demolishing and rebuilding your home, or moving your home to a site outside of the floodplain.

Please resubmit your permit application along with plans and specifications that incorporate

compliance measures. Construction activities that are undertaken without a proper permit are

violations and may result in citations, fines, or other legal action.
Sample Letter to Notify Property Owners of a Determination That 

Work Does NOT Constitute Repair of Substantial Damage

Notice of Determination (Residential)

Dear Property Owner:

We have reviewed your recent application for a permit to repair your existing building that was

damaged by [insert cause of damage]. The building is located in a mapped Special Flood Hazard Area. As required by our floodplain management regulations and/or building code, we

have determined that the work proposed to repair the damage does not constitute repair of

substantial damage. This determination is based on a comparison of the cost estimate of the

work required to restore the building to its pre-damage condition to the market value of the

building.

Please be advised that we will make another determination if you elect to perform work other than what is necessary to repair the damage, such as additional renovations or upgrades or

building an addition. Construction activities that are undertaken without a proper permit are

violations and may result in citations, fines, or other legal action.