Hazard-Resilient Buildings: Sustaining
August 15, 2022
Occupancy and Function After a Natural
Linda R. Rowan
Disaster
Analyst in Natural
Resources Policy
Natural disasters contributed to more than $2.2 trillion in total losses in the United States

between 1980 and 2021. Many in Congress are interested in reducing the losses due to buildings
damaged or destroyed in disasters. One way to reduce losses and help communities recover more

rapidly without disruptions or additional losses is to construct new buildings (or retrofit existing
buildings) that are hazard resilient—that is, that are capable of being occupied and remaining functional during and/or
immediately after a disaster.
Congress directed the Federal Emergency Management Agency (FEMA), the National Institute of Standards and Technology
(NIST), and stakeholders to recommend ways to make buildings hazard resilient, with the aim of reducing disaster losses and
enhancing community resilience. Two reports, one submitted to Congress in 2018 and one in 2021, recommended that the
federal government and stakeholders enhance hazard-resilient designs in model building codes and facilitate adoption and
enforcement of these codes at the community level.
The recommendations in these reports encouraged more research and development in four areas to move toward more
hazard-resilient buildings: (1) building design, (2) community planning, (3) economic and social feasibility, and (4) adoption
of building codes. In addition, the reports recommended that the federal government lead development of a national
framework to increase hazard-resilient building stock nationwide. A national framework may include a national consensus
that defines what services and design requirements are necessary for buildings’ occupancy and function soon after a disaster.
A national framework also may include coordinated, consistent hazard-resilient building assistance and incentive policies.
Coordination may be between different federal government entities or programs and between the federal government and
communities (including state, local, tribal, and territorial entities, as well as the private sector).
Congress established the National Flood Insurance Program, the National Earthquake Hazards Reduction Program, the
National Windstorm Impact Reduction Program, and Hazard Mitigation Assistance Grants, among other initiatives, to reduce
losses from hazards, including through designing buildings that are more resistant to hazards. FEMA, NIST, the National
Oceanic and Atmospheric Administration, the National Science Foundation, and the U.S. Geological Survey have additional
activities and programs that may increase both the hazard resiliency of buildings and the number of buildings that may
perform beyond life safety to allow occupancy and function during or soon after a disaster.
Congress may consider the recommendations in the 2018 and 2021 reports and whether to take any action related to these
recommendations. Congress also may consider whether current federal agency activities or grant programs respond to some
or all of the recommendations. In addition, Congress could consider directing federal programs to promote the adoption of
model building codes that address occupancy and function through incentives or mandates. Congress also could incentivize
code adoption by offering discounts on insurance premiums, tax credits, or access to additional resources for code
improvements through grants or loans.

Congressional Research Service

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

Introduction
Residential and commercial buildings facilitate residential, commercial, industrial, social,
cultural, educational, and government functions for communities.1 At times, natural disasters have
damaged or destroyed buildings in the United States, causing additional economic, social, and
cultural losses.2 Many in Congress have indicated an interest in policies and activities to make
buildings more hazard resilient, such that buildings suffer minimal damage, can be reoccupied,
and can function immediately after a disaster. In the aftermath of a disaster, minimally damaged
buildings may reduce immediate losses and may allow communities to recover rapidly and avoid
additional losses.
According to the National Oceanic and Atmospheric Administration (NOAA), the United States
sustained 323 weather and climate disasters that each resulted in overall losses at or above $1
billion from 1980 through 2021.3 The total inflation-adjusted loss caused by these 323 events is
nearly $2.2 trillion.4 Non-weather hazards, such as earthquakes, also may damage buildings and
cause large economic losses. According to the U.S. Geological Survey (USGS), nearly half of all
Americans are exposed to earthquake hazards and past earthquake events have caused significant
damage to buildings.5 For example, the 1994 magnitude 6.7 Northridge earthquake in California
caused economic losses of $42 billion (1998 dollars), damaged more than 114,000 buildings, and
left more than 22,000 people homeless. Total insured losses caused the collapse of the earthquake
insurance industry in California.6
The primary way to affect building performance objectives is through building codes, which are
adopted and enforced by state, local, tribal, and territorial governments (SLTTs).7 Currently, most

1 In this report, buildings refer to existing buildings that may need retrofits and to newly constructed buildings.
Residential buildings include one- and two-family dwellings and townhouses not more than three stories above grade
and account for about 80% of building stock in the United States. Commercial buildings include commercial,
industrial, educational, government, and larger residential structures, such as apartment buildings. International Code
Council (ICC), “Overview of the International Residential Code (IRC),” at https://www.iccsafe.org/products-and-
services/i-codes/2018-i-codes/irc/.
2 The Federal Emergency Management Agency (FEMA) defines natural disaster as any natural hazard event that
causes significant harm to life, property, or society. FEMA, Building Codes Save: A Nationwide Study, November
2020, at https://www.fema.gov/emergency-managers/risk-management/building-science/building-codes-save-study
(hereinafter FEMA, Building Codes Save, 2020).
3 The National Oceanic and Atmospheric Administration (NOAA) defines weather and climate disaster as drought,
wildfire, flood, winter storm, freeze, severe storm (includes hail, tornado, and high wind), and tropical cyclone (i.e.,
hurricane). NOAA does not provide separate descriptions of weather disasters versus climate disasters. See NOAA,
“Billion-Dollar Disasters: Calculating the Costs,” at https://www.ncei.noaa.gov/access/monitoring/dyk/billions-
calculations; and CRS In Focus IF11446, Weather and Climate Change: What’s the Difference?, by Jane A. Leggett.
4 NOAA’s calculations include losses due to damage to the built environment, which are often among the highest losses
from a natural disaster. The calculated losses include damage to residential, commercial, and municipal buildings;
material assets (content) within buildings; vehicles and boats; and roads, bridges, and utilities. NOAA also estimates
time element losses such as business interruption or loss of living quarters. NOAA, “Billion-Dollar Disasters:
Calculating the Costs,” at https://www.ncei.noaa.gov/access/monitoring/dyk/billions-calculations.
5 Kishor S. Jaiswal et al., “Earthquake Shaking Hazard Estimates and Exposure Changes in the Conterminous United
States,” Earthquake Spectra, vol. 31, no. 1 (2015), pp. S201-S220, at https://doi.org/10.1193/111814EQS195M.
6 William J. Petak and Shirin Elahi, “The Northridge Earthquake, USA and Its Economic and Social Impacts,”
presented at EuroConference on Global Change and Catastrophe Risk Management, International Institute for Applied
Systems Analysis, Laxenburg, Austria, July 6-9, 2000, at https://abag.ca.gov/sites/default/files/
the_northridge_earthquake_and_its_economic_and_social_impacts.pdf.
7 Building codes are officially adopted minimum requirements for the design, construction, alteration, materials,
maintenance, and performance of buildings to provide a minimum level of safety, public health, and welfare. A model
Congressional Research Service

1

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

building codes require a habitable structure that protects people from injury or death and do not
require occupancy or functionality soon after a disaster.8 The federal government plays almost no
role in establishing and enforcing building codes in communities. However, federal agencies such
as the National Institute of Standards and Technology (NIST) and the Federal Emergency
Management Agency (FEMA) may facilitate design and implementation of building codes and
also may encourage or incentivize adoption and enforcement of hazard-resilient model building
codes.9
Congress has directed NIST, FEMA, and stakeholders to recommend research and
implementation activities to advance building performance beyond life safety to occupancy and
functionality during or soon after a disaster.10 The Senate Committee on Appropriations, in
S.Rept. 114-239 accompanying the Consolidated Appropriations Act, 2017 (P.L. 115-31),
recognized that current building codes did not provide enough protection from natural disasters to
enable “immediate occupancy” following a disaster. The committee asked NIST to prepare a plan
describing research and implementation activities needed to develop “immediate occupancy”
engineering design principles and building performance objectives for commercial and residential
properties. NIST submitted to Congress a report entitled Research Needs to Support Immediate
Occupancy Building Performance Objectives Following Natural Hazards Events in 2018
(hereinafter referred to as the IO report).11
In the 2018 reauthorization of the National Earthquake Hazards Reduction Program (NEHRP;
P.L. 115-307, 42 U.S.C. §7705b), Congress requested that NIST and FEMA jointly convene a
panel of experts to assess and recommend options for improving the built environment and
critical infrastructure to allow occupancy and function immediately after an earthquake. The
agencies submitted to Congress a report entitled Recommended Options for Improving the Built
Environment for Post-Earthquake Reoccupancy and Functional Recovery Time in 2021
(hereinafter referred to as the FRT report).12
In addition, Congress directed NIST and FEMA to take other actions that may contribute to the
development of hazard-resilient buildings. The 2018 reauthorization of NEHRP defined

building code is a building code that is developed and maintained by a standards developing organization (SDO)
independent of the jurisdiction responsible for adopting and enforcing any building codes.
8 Building codes adopted and enforced by jurisdictions vary. FEMA tracks building codes in use by communities and
notes that some of these codes include hazard-resistant design elements, which may improve a building’s ability to
withstand a disaster and to be occupied and functional soon after a disaster. Critical buildings, such as hospitals and
emergency response centers, are built to codes that require continued occupancy and function during and after a
disaster. FEMA, “Nationwide Building Code Adoption Tracking,” at https://www.fema.gov/emergency-managers/risk-
management/building-science/bcat.
9 Federal entities are required to construct new buildings or alter existing buildings (owned or leased) using the latest
edition of one of the “nationally recognized model building codes” (40 U.S.C. §3312). In addition, the Department of
Housing and Urban Development (HUD) issues and enforces standards for the construction, design, performance, and
installation of manufactured homes (i.e., HUD sets the building codes, and these codes differ from codes used for other
buildings in the United States). National Manufactured Housing Construction and Safety Standards Act of 1974 (42
U.S.C. §5401-5426). Regulations are at 24 C.F.R. parts 3280, 3282, 3284, 3285, 3286, 3288, and 3800.
10 Stakeholders may include hazard scientists, architects, engineers, builders, developers, community planners, building
managers, building standards developers, state or local government officials, and others.
11 Siamak Sattar et al., Research Needs to Support Immediate Occupancy Building Performance Objective Following
Natural Hazard Events, National Institute of Standards and Technology (NIST), NIST Special Publication 1224,
August 2018, at https://doi.org/10.6028/NIST.SP.1224 (hereinafter IO report).
12 NIST-FEMA, Recommended Options for Improving the Built Environment for Post-Earthquake Reoccupancy and
Functional Recovery Time, NIST-FEMA Special Publication FEMA P-2090/NIST SP-1254, 2021, at https://doi.org/
10.6028/NIST.SP.1254 (hereinafter FRT report).
Congressional Research Service

2

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

community resilience as “the ability of a community to prepare and plan for, absorb, recover
from, and more successfully adapt to adverse seismic events” (42 U.S.C. §7703) and directed
NIST to conduct research to “improve community resilience through building codes and
standards” (42 U.S.C. §7704(b)(5)). Further, Congress amended Section 203 of the Robert T.
Stafford Disaster Relief and Emergency Assistance Act (Stafford Act) to permit FEMA grant
funding to communities to adopt and enforce the “latest published editions of relevant consensus-
based codes, specifications, and standards that incorporate the latest hazard-resistant designs” (42
U.S.C. §5172(e)(1)(A)).13
The recommendations from the IO and the FRT reports sought to increase the number of hazard-
resilient buildings, leading to more resilient communities.14 The recommendations did not specify
actions by any federal agencies or stakeholders; however, ongoing activities at NIST and FEMA
may support some aspects of these recommendations.
Recommendations to Increase Hazard-Resilient
Building Stock
The IO and FRT reports encouraged development of a national framework for hazard-resilient
building design and construction that may be connected to a national framework for resilient
infrastructure design and construction.15 A national framework for building design may require a
consensus about what services and design requirements are necessary for the occupancy and
function of buildings within some specified time frame after a disaster.
In addition, the reports recommended research and development (R&D) in four areas:
(1) building design, (2) community planning, (3) economic and social feasibility, and (4) building
codes adoption.
Terminology: Occupancy, Function, and Resilience
Hazard-resilient buildings are intended to maintain occupancy and functionality with minimal
repairs during and after a natural disaster. The IO report stated that an immediate occupancy

13 The amendment to the Robert T. Stafford Disaster Relief and Emergency Assistance Act is in Division D, Disaster
Recovery Reform Act of the Federal Aviation Administration Reauthorization Act of 2018 (DRRA; P.L. 115-254). It
established FEMA Building Resilient Infrastructure and Communities (BRIC) grants, which may be used to help
communities adopt and enforce hazard-resistant building codes and standards. See FEMA, BRIC Building Code
Activities, FEMA Program Support Materials, August 2021, at https://www.fema.gov/sites/default/files/documents/
fema_fy21-bric-building-code-activities-psm.pdf. For more information about FEMA Hazard Mitigation Assistance,
see CRS Report R46989, FEMA Hazard Mitigation: A First Step Toward Climate Adaptation, by Diane P. Horn. For
more about DRRA, see CRS Report R45819, The Disaster Recovery Reform Act of 2018 (DRRA): A Summary of
Selected Statutory Provisions, coordinated by Elizabeth M. Webster and Bruce R. Lindsay.
14 The IO report did not specify any particular hazard type but noted that buildings may need to be designed for a
specific hazard type and intensity level. The FRT report focused on earthquake hazards but noted that the
recommended approaches may apply to other hazard types. Both reports noted the importance of considering multi-
hazards (e.g., a building may be impacted by an earthquake and a hurricane at different times, or a building may be
impacted by an earthquake that triggers a tsunami, resulting in shaking followed by water inundation at nearly the same
time or over a matter of hours).
15 The IO report focused on buildings while noting that infrastructure would need consideration. The FRT report
discussed hazard-resilient buildings and infrastructure separately and noted that some aspects of building resilience
depend on infrastructure resilience (e.g., a supply of power and water to a building may be necessary for occupancy and
function after a natural disaster).
Congressional Research Service

3

link to page 4 Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

performance objective may enable buildings to remain functional or to experience interim loss of
function for a limited time, while repairs may take place during occupancy and basic
functioning.16 The FRT report defined reoccupancy as a post-earthquake performance state in
which a building is maintained or restored to allow safe reentry for the purposes of providing
shelter or protecting building contents. The time frame for reoccupancy may vary, and an
acceptable time frame for reoccupancy may depend on the building’s occupancy levels and
functions. Functional recovery is a post-earthquake performance state in which the building is
maintained or restored to safely and adequately support its basic intended functions.17 The
functional recovery time is the amount of time it may take a building to recover certain basic
functions after a disaster. The time may be specified in hours, days, weeks, or months, based on
the hazard’s intensity, the building’s functions and occupancy levels, and other factors.
The reports considered hazard-resilient buildings to be one component of resilient communities.
Both reports used the definition of resilience from the Presidential Policy Directive 21 (PPD-21):
“The term ‘resilience’ means the ability to prepare for and adapt to changing conditions and to
withstand and recover rapidly from disruptions. Resilience includes the ability to withstand and
recover from deliberate attacks, accidents, or naturally occurring threats or incidents.”18 This
definition is similar to the definition of community resilience to earthquakes in the 2018
reauthorization of NEHRP (see “Introduction”) and to NIST’s definition of community
resilience.19 Congress directed FEMA to define resilient and resiliency as part of an amendment
to the Stafford Act (42 U.S.C. §5172(e)) in the Disaster Recovery Reform Act (P.L. 115-254).20
FEMA has indicated that it is in the rulemaking process to adopt NIST’s community resilience
definition.
National Framework for Building Design
A national framework for hazard-resilient building design would establish consensus model
building codes and consensus hazard-resistant design elements that are based on identified hazard
risks in different communities; such a framework could be efficiently and consistently used
nationwide. Standard-developing organizations (SDOs) develop and update model building codes
through input and a consensus-based process involving experts and stakeholders. SLTTs may
choose to adopt some or all of such model building codes or establish their own building codes.
SLTTs are responsible for enforcing their building codes within their jurisdictions. The most
common model building codes that are adopted in the United States are from two SDOs, the
International Code Council (ICC, which publishes 15 types of model building codes referred to
collectively as I-Codes) and the National Fire Protection Association.21 In addition to these model

16 IO report, p. 3.
17 FRT report, p. vi.
18 White House, Office of the Press Secretary, “Presidential Policy Directive – Critical Infrastructure Security and
Resilience,” PPD-21, February 12, 2013, at https://obamawhitehouse.archives.gov/the-press-office/2013/02/12/
presidential-policy-directive-critical-infrastructure-security-and-resil.
19 NIST defines community resilience as “the ability to prepare for anticipated hazards, adapt to changing conditions,
and withstand and recover rapidly from disruptions.” See NIST, “Community Resilience,” at https://www.nist.gov/
community-resilience. See also CRS Report R46774, The Disaster Recovery Reform Act of 2018 (DRRA):
Implementation Update Tables for Select Provisions, coordinated by Elizabeth M. Webster.
20 See CRS Report R45819, The Disaster Recovery Reform Act of 2018 (DRRA): A Summary of Selected Statutory
Provisions, coordinated by Elizabeth M. Webster and Bruce R. Lindsay.
21 IO report, p. 9; ICC, “International Code Council,” at https://www.iccsafe.org/; and National Fire Protection
Association at https://www.nfpa.org/.
Congressional Research Service

4

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

building codes, other organizations may provide design standards that are included in model
building codes. The most commonly used minimum design standards for hazards that are
referenced in I-Codes are from the American Society of Civil Engineers (ASCE). The ASCE’s
Structural Engineering Institute (SEI) has developed hazard load(s) (e.g., snow, wind, and/or
seismic loads) for general design construction called Minimum Design Loads and Associated
Criteria for Buildings and Other Structures (ASCE/SEI 7).22 ASCE also has a Flood Resistant
Design and Construction (ASCE/SEI 24) standard for flood loads for buildings constructed in
flood hazard areas. According to FEMA, ASCE/SEI 24 meets or exceeds the minimum design
requirements of the National Flood Insurance Program for buildings and structures.23
The ASCE 7 provides minimum design loads for a building based on the building’s assigned risk
category.24 The four categories are as follows:
 Risk Category I: buildings that pose a low risk to human life in the event of
failure (e.g., storage facilities, barns)
 Risk Category II: all buildings except those classified as Risk Categories I, III,
and IV and most commercial and residential buildings
 Risk Category III: buildings designed to accommodate a high number of
occupants, potentially posing substantial risk to human life in the event of failure
(e.g., schools, theatres)
 Risk Category IV: buildings classified as essential facilities, the failure of which
could pose substantial hazard to the community (e.g., hospitals)
Hazard-resilient model codes and design elements may include functional recovery time
categories for specific hazards and hazard intensity levels (i.e., a specific time of days, weeks, or
months to recover particular functions for a specified hazard intensity level), which may be
applied to different building risk categories. Local communities may adopt these codes and
design elements and may customize them for community needs.25 For example, a community that
is vulnerable to hurricanes could adopt the hurricane-resistant model codes and may consider
including additional design elements that make buildings even more hurricane resistant (e.g.,

22 American Society of Civil Engineers (ASCE), “ASCE 7,” at https://www.asce.org/publications-and-news/asce-7.
Minimum design load refers to the minimum hazard intensity that the building should be able to withstand without
impacting building life safety or, for critical buildings such as hospitals, without impacting occupancy and function.
For example, a minimum design load may be a wind speed of 100 miles per hour that a two-story house should be able
to withstand without damage or collapse that would impact the safety of the building inhabitants. A building could be
designed to withstand a higher wind speed event; the code specifies only a minimum wind speed (i.e., minimum design
load). Please note that the acronym ASCE/SEI 7 may also be referred to as ASCE 7, ASCE 7-22 or ASCE/SEI 7-22
where the 22 refers to the year of the design edition. ASCE/SEI 7-22 is the latest edition and was published in 2022.
23 FEMA, “American Society of Civil Engineers - Flood Resistant Design and Construction,” https://www.fema.gov/
node/american-society-civil-engineers-flood-resistant-design-and-construction. ASCE/SEI 24 may be called ASCE 24
or ASCE/SEI 24-14 (the latest edition of ASCE/SEI 24 was published in 2014).
24 IO report, p. 13 and Engineering Express, “ASCE Risk Categories Explained,” at
https://www.engineeringexpress.com/wiki/asce-risk-categories-explained/.
25 ASCE provides an online hazard tool that allows a stakeholder to choose a location, building risk category, and
hazard type, then the tool returns the minimum design load standard (such as wind speed based on ASCE/SEI 7) that a
building should meet based on the criteria chosen. See ASCE, “ASCE 7 Hazard Tool,” at
https://asce7hazardtool.online/. Even if a stakeholder is not designing or constructing a building, he or she can view the
minimum design load criteria for many different hazards at a location to gain knowledge about hazard risks and
building performance design elements for these hazards.
Congressional Research Service

5

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

Florida building code requires design elements for high-velocity hurricane winds and wind-borne
debris hazards in specific coastal zones across the state).26
No federal statutes establish national model building codes. Instead, any statutes mentioning
building codes call for the adoption of either the latest edition of any nationally recognized model
codes or the most recent edition of any relevant, consensus-based model codes.27 SDOs revise
their model building codes about every three to six years through a consensus-based process, and
the most recent edition of I-Codes is from 2021.28 Any stakeholder, including a federal agency
such as NIST or FEMA, can offer a new or improved design element that may be considered for
inclusion in the next edition of the model building codes.29 Over time, hazard-resistant design
elements have been added to the model codes. Examples include elevating structures for flood
resistance, using more secure roof elements and adding window shutters for hurricane resistance,
and using stronger and/or stiffer materials for earthquake resistance.
Building Design Considerations
The IO and FRT reports encouraged the adoption of building codes that prescribe hazard-resilient
design and construction practices. The reports also called for R&D on enhanced engineering
design and construction practices to make buildings more hazard resilient. For example, R&D on
steel columns produced an improved design element for enhanced earthquake resistance; NIST
submitted this design element to the ICC for consideration in the next edition of I-Codes.30
In addition to calling for R&D, the reports provided two overarching recommendations for
building design: (1) adopt Risk Category IV building codes for all buildings and (2) move toward
performance-based designs.
Risk Category IV Building Codes
Some critical buildings, such as hospitals and emergency operation centers, are designed and
constructed to be occupied and remain functional during and after a disaster. These buildings are
in the highest risk category (IV) of model building codes. One recommendation is to expand these
design and construction practices to all buildings. This recommendation may be challenging to
implement because of the differences in building function. A hospital, for example, serves a very
different function than a one-family dwelling. Nevertheless, because Risk Category IV design and
construction practices are already part of adopted building codes in many communities, it may be
efficient and feasible to start with these standards.

26 See Florida Building Commission, Florida Department of Community Affairs, “Setting New Standards for Safety,
The Florida Building Code,” at https://www.floridabuilding.org/fbc/publications/fbc.pdf.
27 For example, federal entities are required to construct new buildings or alter existing buildings (owned or leased)
using the latest edition of one of the “nationally recognized model building codes” (40 U.S.C. §3312) and FEMA may
grant funding to communities to adopt and enforce the “latest published editions of relevant consensus-based codes,
specifications, and standards that incorporate the latest hazard-resistant designs” (42 U.S.C. §5172(e)(1)(A)).
28 ICC, “IBC Reference,” at https://shop.iccsafe.org/international-codes/ibc-references.html.
29 For example, FEMA recommended new earthquake-resistant design elements for possible inclusion in model
building codes. FEMA, “NEHRP Recommended Seismic Provisions for New Buildings and Other Structures,” January
7, 2022, at https://www.fema.gov/node/nehrp-recommended-seismic-provisions-new-buildings-and-other-structures.
30 NIST, “Proposed Updates to Steel Building Standard Could Enhance Earthquake Resilience,” at
https://www.nist.gov/news-events/news/2022/01/proposed-updates-steel-building-standard-could-enhance-earthquake.
Congressional Research Service

6

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

Performance-Based Design
Engineering and construction professionals may need to move from prescriptive design (PD) to
performance-based design (PBD) for some building elements because those elements must
perform to some specified level for a specific hazard (e.g., a steel beam must perform to a certain
strength and stiffness to resist a specified shaking intensity caused by an earthquake).31 PD is
used for most building codes and prescribes the design criteria (e.g., the maximum stud spacing
on the first floor of a two-story house). PBD sets the criteria based on the performance of the
building element (e.g., the compressive stress of the lumber may not exceed some maximum
value for the floor). PBD may be more complex to implement than PD, may require additional
analysis before the standards can be applied to building construction or retrofitting, and may not
be feasible for all of the components of model building codes or for all types of hazards.
Research and Development for Hazard-Resilient Building Design
The IO and FRT reports recommended three avenues of R&D in design and construction
practices:
1. Determine the hazards, hazard intensity levels, and building response to different
hazards (e.g., assessing post-disaster damage, modeling potential damage from
disaster scenarios)
2. Determine the functional recovery time to prescribe for different hazards, hazard
intensity levels, and building types (e.g., for a moderate earthquake, a
commercial building should regain certain functions within a week)
3. Develop hazard-resilient innovations in materials, designs, design methods,
modeling, and construction practices
Community Planning Considerations
The IO and FRT reports recommended R&D on community planning to determine how hazard-
resilient buildings fit into community resilience and contribute to supporting, for example, health
care, education, business, and governance. In addition, the reports noted that communities may
address buildings’ occupancy and functional recovery times through pre-disaster recovery
planning. Pre-disaster recovery planning allows a community to consider the whole community
system and all of the system parts to identify and mitigate weaknesses that may prevent recovery.
For example, if the power supply to a building is lost but the community has alternative power
supply plans in place, then a building may be occupied and remain functional using the
alternative power supply after a disaster.
Economic and Social Feasibility Considerations
The IO and FRT reports recommended further research, analysis, and assessment of the economic
and social feasibility of hazard-resilient buildings at the local, regional, and national scales (e.g.,
the costs for new buildings or for retrofitting older buildings over the building lifecycle).
Research also may consider broader economic impacts, such as how a business could function
after a disaster and how that ability may affect decisions to build or locate in a hazard-resilient

31 IO report, p. 14.
Congressional Research Service

7

link to page 12 link to page 13 link to page 14 Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

building. In addition, the reports recommended research on social feasibility, such as
stakeholders’ perceptions of risks.32
Adoption and Acceptance Considerations
The IO and FRT reports noted that the primary mechanism for achieving hazard-resilient
buildings is the adoption and enforcement of hazard-resilient building codes. Therefore,
establishing national model building codes that are understood by, and acceptable to,
communities may be a feasible starting point. Additional R&D on community needs, perceptions,
and the effectiveness of adopted community building codes may inform approaches for
nationwide adoption of hazard-resilient codes. Advancing a national framework for hazard-
resilient buildings may be the most efficient, consistent pathway to adoption and enforcement of
hazard-resilient building codes in communities.
Federal Role to Increase Hazard-Resilient Building
Stock
Congress established the National Flood Insurance Program, NEHRP, and the National
Windstorm Impact Reduction Program (NWIRP) in part to reduce damages and losses to
buildings from floods, earthquakes, and damaging winds.33 These programs involve FEMA,
NIST, the National Science Foundation, the USGS, and/or NOAA in efforts to identify the
hazards (including their frequency, intensity levels, and the damage they may inflict on buildings)
and to identify ways to mitigate the impacts of these hazards on the built environment. For
example, FEMA has identified the hazards most likely to affect buildings in different parts of the
country (Figure 1). In addition, the IO report replotted NOAA’s billion-dollar weather and
climate disasters data to show the frequency of different hazards (e.g., hurricanes or floods) by
state (Figure 2). The USGS provides earthquake probability assessments, and these probabilities
may be used to assess the intensity and frequency of earthquakes on the built environment
(Figure 3).

32 Hazard is not the same as risk; hazard is a source of danger, whereas risk is the possibility of loss or injury.
33For more information, see CRS Report R43141, The National Earthquake Hazards Reduction Program (NEHRP):
Issues in Brief, by Linda R. Rowan; CRS In Focus IF10988, A Brief Introduction to the National Flood Insurance
Program, by Diane P. Horn; and the following federal agency websites: NEHRP, “National Earthquake Hazards
Reduction Program,” at https://www.nehrp.gov/; NIST, “National Windstorm Impact Reduction Program,” at
https://www.nist.gov/el/materials-and-structural-systems-division-73100/national-windstorm-impact-reduction-
program-nwirp; and FEMA, “Flood Insurance,” at https://www.fema.gov/flood-insurance.
Congressional Research Service

8

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

Figure 1. FEMA Map of Dominant Hazards in the United States

Source: Federal Emergency Management Agency (FEMA), Protecting Communities and Saving Money: The Case for
Adopting Building Codes, November 2020, at https://www.fema.gov/sites/default/files/2020-11/fema_building-codes-
save_brochure.pdf.
Notes: FEMA estimates that seismic activity, hurricane winds, tornadoes, and floods represent dominant hazards
in the United States relative to other natural hazards, based on the number of occurrences of these hazards and
the amount of losses due to damage to buildings from these hazards in the past.
Congressional Research Service

9

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

Figure 2. NOAA Billion-Dollar Weather and Climate Disasters Frequency by State
(From 1980 to 2017, by hazard type)

Sources: Siamak Sattar et al., Research Needs to Support Immediate Occupancy Building Performance Objective
Following Natural Hazard Events, National Institute of Standards and Technology (NIST), NIST Special Publication
1224, August 2018, at https://doi.org/10.6028/NIST.SP.1224, using data from National Oceanic and Atmospheric
Administration (NOAA), National Centers for Environmental Information, “Bil ion-Dol ar Weather and Climate
Disasters: Overview,” 2018, at http://www.ncdc.noaa.gov/bil ions/.
Notes: Frequency with which each state has been impacted by a disaster exceeding $1 bil ion in damage
between 1980 and 2017. For example, 15 drought disasters impacted Texas, totaling more than $1 bil ion for
each occurrence, between 1980 and 2017 (upper left panel). NOAA estimates the total cost for each disaster as
the cost in terms of dol ars that would not have been incurred had the event not taken place. The dol ar
amounts are adjusted for inflation. The costs include physical damage to residential, commercial, and municipal
buildings; material assets (content) within buildings; time element losses such as business interruption or loss of
living quarters; damage to vehicles and boats; public assets including roads, bridges, levees; electrical
infrastructure and offshore energy platforms; agricultural assets including crops, livestock, and commercial
timber; and wildfire suppression costs, among others. NOAA estimates that increases in population and material
wealth, population centers and infrastructure in vulnerable areas such as coasts and river floodplains, and climate
change impacts contribute to the costs of weather and climate disasters. NOAA also notes that building codes
are often insufficient in reducing damage from these extreme events. See NOAA, “Bil ion-Dol ar Disasters –
Calculating the Costs,” at https://www.ncei.noaa.gov/access/monitoring/dyk/bil ions-calculations.
Congressional Research Service

10

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

Figure 3. USGS Seismic Hazard Map
(probability of a Modified Mercalli Intensity VI earthquake in 100 years, expressed as a percentage)

Source: U.S. Government Accountability Office (GAO), Earthquakes: Progress Made to Implement Early Warning
System, But Actions Needed to Improve Program Management, GAO-21-129, March 2019.
Notes: The Modified Mercalli Intensity Scale from Roman numeral I to X represents the shaking intensity from
an earthquake felt by people or damaging property. Intensity VI is strong shaking that is felt by everyone and
causes slight damage to property. See U.S. Geological Survey (USGS), “The Modified Mercalli Intensity Scale,” at
https://www.usgs.gov/programs/earthquake-hazards/modified-mercalli-intensity-scale. See also CRS Report
R43141, The National Earthquake Hazards Reduction Program (NEHRP): Issues in Brief, by Linda R. Rowan.
FEMA Programs and Activities
FEMA’s Building Science program, plus its NEHRP and NWIRP activities, supports R&D for
improving building codes, gaining adoption of hazard-resistant model building codes, and other
activities. 34 In addition, FEMA’s Public Assistance Program and Hazard Mitigation Assistance
Grants program may incentivize, encourage, or help facilitate the adoption of hazard-resistant
model building codes leading to more hazard-resilient buildings.35 These programs and activities
may align with the recommendations in the IO and FRT reports.

34 FEMA describes hazard-resistant model building codes as the 2018 or later editions of I-Codes. FEMA, “2022
Building Code Adoption Tracking Overview,” fact sheet, February 2022, at https://www.fema.gov/sites/default/files/
documents/fema_fy22-about-bcat-report.pdf. These model codes contain design elements that allow buildings to better
withstand hazards; in some cases, this resistance may allow occupancy and function soon after a disaster. For more
information about FEMA programs and activities, see FEMA, “Risk Management,” at https://www.fema.gov/
emergency-managers/risk-management.
35 FEMA, “Assistance for Governments and Private Non-Profits After a Disaster,” at https://www.fema.gov/assistance/
public; and FEMA, “Hazard Mitigation Assistance Grants,” at https://www.fema.gov/grants/mitigation. See also CRS
Insight IN11733, Recent Funding Increases for FEMA Hazard Mitigation Assistance, by Diane P. Horn.
Congressional Research Service

11

link to page 15 Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

FEMA program activities identify the location, frequency, and intensity of hazards that may
damage buildings, consider how different hazards may damage buildings, and conduct R&D on
hazard-resilient building design and construction.36 The programs may suggest model building
code design elements to SDOs. In addition, the program tracks building code adoption in the
United States to help understand, at a national level, the state of resiliency across communities.37
A study led by FEMA, entitled Building Codes Save: A Nationwide Study, looked at 18.1 million
buildings constructed between 2000 and 2016 (more than 85% of these buildings were residential
construction) and estimated the amount of damage these structures might incur from the three
most common hazards: floods, hurricanes, and earthquakes.38 The findings showed that about half
the buildings (roughly 9.1 million) were built to I-Codes (2000 or later editions) and would lead
to average annualized losses avoided of approximately $1.6 billion (2020 dollars).39 The study
noted that recent I-Codes (2015 or 2018 editions) were designed for life safety and to reduce
property damage up to a defined risk threshold to increase the number of hazard-resistant
buildings in communities nationwide. According to FEMA’s Nationwide Building Code
Adoption Tracking (Table 1), a low-to-medium percentage (11%-54%) of building stock in
approximately 22,000 jurisdictions is resistant to specific hazards.
Table 1. Hazard-Resistant Code Adoption Statistics
(As of FY2022, second quarter)
Hazard
Resistant Percentage of Building Stock (%)
Damaging Wind
25
Hurricane Wind
54
Tornado
11
Flood
25
Earthquake
49
Combined
25
Source: FEMA, “Nationwide Building Code Adoption Tracking,” at https://www.fema.gov/emergency-managers/
risk-management/building-science/bcat.
Notes: FEMA tracks hazard-resistant building code adoption status for state, local, tribal and territorial
governments, covering approximately 22,000 jurisdictions across the nation. The resistant percentage is the
percentage of modern building codes in use by these communities that include hazard-resistant designs for
specific hazards. FEMA considers hazard-resistant codes as the adoption of the 2018 or later editions of the
International Code Council (ICC) model building codes (I-Codes), along with the hazard-resistant design
standards from the American Society of Civil Engineers, Structural Engineering Institute’s Minimum Design Loads
and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7-14 or later editions) and Flood Resistant Design

36 FEMA, “Building Science,” at https://www.fema.gov/emergency-managers/risk-management/building-science; and
FEMA, “Hazard Mitigation Assistance Grants,” at https://www.fema.gov/grants/mitigation.
37 FEMA, “Nationwide Building Code Adoption Tracking,” at https://www.fema.gov/emergency-managers/risk-
management/building-science/bcat.
38 The 18.1 million new buildings in the study may be divided into about 15.4 million one- and two-family dwellings;
0.5 million other residential buildings; 0.7 million commercial and industrial buildings; and 1.6 million other buildings,
such as educational, religious, and government buildings. Numbers from Table 3-3, FEMA, Building Codes Save,
2020. The most recent codes at the time of this study were from 2018. The ICC has since updated its codes, so the most
recent editions are from 2021. ICC, “IBC Reference,” at https://shop.iccsafe.org/international-codes/ibc-
references.html.
39 The losses are for physical damage to buildings and do not include any economic, social, cultural, or government
losses related to the loss of function of the buildings. FEMA, Building Codes Save, 2020.
Congressional Research Service

12

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

and Construction (ASCE/SEI 24-14) design standard for flood loads for buildings constructed in flood hazard areas.
I-Codes include the ASCE design standards. A jurisdiction that adopts I-Codes may choose to exclude some or
parts of the ASCE design standards, so FEMA specifies the importance of adopting and enforcing I-Codes and
ASCE design standards in their hazard-resistant building code adoption tracking.
FEMA has published a Building Code Strategy with three goals: (1) integrate building codes and
standards across FEMA, (2) strengthen nationwide capability for superior building performance,
and (3) drive public action on building codes.40 Although the Building Code Strategy and the
Building Codes Save report do not mention occupancy or functional recovery time, the objective
of reducing property damage for a defined hazard level may contribute to increasing the
probability of occupancy and functional recovery. Some of these strategies, including the
following, are similar to the IO and FRT reports’ recommendations:
 Advance building code research and use data-driven decisionmaking to guide the
application of codes
 Understand stakeholder needs to identify opportunities that advance code
adoption and enforcement
 Implement 2018 or 2021 editions of I-Codes across FEMA policies and programs
and improve coordination and governance of code activities throughout FEMA
In addition to these activities, the Biden Administration announced a National Initiative to
Advance Building Codes on June 1, 2022.41 The initiative aims to help communities adopt current
model building codes to make buildings more resilient to disasters and more energy efficient.42
The Mitigation Framework Leadership Group, a collaborative interagency body, aims to identify
opportunities for federal agencies to assist communities to adopt current model building codes.43
For example, FEMA plans to implement its Building Code Strategy and use its Building Code
Adoption Tracking portal. In another example, the Department of Housing and Urban
Development is to require increased resilience and energy efficiency standards for residential
properties constructed or rehabilitated through the 2020 and 2021 Community Development
Block Grant-Disaster Recovery funds.
NIST Programs and Activities
NIST activities to advance hazard-resilient buildings are organized primarily within the
Engineering Laboratory under Disaster-Resilient Buildings, Infrastructure, and Communities.44

40 FEMA, Building Codes Strategy, March 2022, at https://www.fema.gov/emergency-managers/risk-management/
building-science/building-codes-strategy.
41 White House, “Fact Sheet: Biden-Harris Administration Launches Initiative to Modernize Building Codes, Improve
Climate Resilience, and Reduce Energy Costs,” press release, June 1, 2022, at https://www.whitehouse.gov/briefing-
room/statements-releases/2022/06/01/fact-sheet-biden-harris-administration-launches-initiative-to-modernize-building-
codes-improve-climate-resilience-and-reduce-energy-costs/.
42 According to an ICC press release, the current model building codes are the current editions of I-Codes. See ICC,
“White House Announces National Initiative to Advance Building Codes Based on the International Codes,” press
release, June 1, 2022, at https://www.iccsafe.org/about/periodicals-and-newsroom/white-house-announces-national-
initiative-to-advance-building-codes-based-on-the-international-codes/.
43 FEMA, “Mitigation Framework Leadership Group (MitFLG),” at https://www.fema.gov/emergency-managers/
national-preparedness/frameworks/mitigation/mitflg#:~:text=
The%20Mitigation%20Framework%20Leadership%20Group,National%20Mitigation%20Framework%20(NMF).
44 NIST Engineering Laboratory, “Strategic Goals and Programs,” at https://www.nist.gov/el/goals-programs; and
NIST, “Earthquake Risk Reduction in Buildings and Infrastructure Program,” at https://www.nist.gov/programs-
projects/earthquake-risk-reduction-buildings-and-infrastructure-program.
Congressional Research Service

13

link to page 11 link to page 11 link to page 11 link to page 11 Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

This mission area includes NEHRP, NWIRP, and Community Resilience Program activities that
support R&D for improving engineering design and construction for hazard resistance and
developing tools and guidelines for communities to improve their resilience, including by
ensuring a resilient building stock.45 These activities may support furthering hazard-resilient
buildings to sustain or rapidly recover occupancy and function after a disaster. In particular, NIST
may provide guidelines and tools to help communities enhance their building code adoption and
enforcement for hazard-resilient buildings. NIST also may submit building code design elements
that enhance hazard resilience to SDOs for possible inclusion in consensus-based model building
codes and may engage in other activities that align with the recommendations in the IO and FRT
reports.
Congressional Considerations
Congress may consider whether to take any action regarding the recommendations in the IO and
FRT reports. The IO report did not recommend any specific actions for Congress, federal
agencies, or particular stakeholders. The FRT report, by contrast, included four actions Congress
could consider. The four suggested actions and some options that Congress may consider are
outlined below.
1. Support R&D in the four areas recommended in the IO and FRT reports.
Congress may consider whether any current federal agency activities or grant
programs (e.g., the programs described in “Federal Role to Increase Hazard-
Resilient Building”) already address some or all of the R&D recommendations.
2. Encourage state and local communities to adopt hazard-resilient building
codes and to engage in recovery-based planning and mitigation. Congress
could consider directing FEMA and NIST programs (see “Federal Role to
Increase Hazard-Resilient Building”) to promote the adoption of building codes
that address occupancy and function (starting with adoption of the 2018 or 2021
editions of I-Codes) and to support recovery-based planning through incentives
or mandates. Congress could incentivize—rather than require—federal agencies
to help communities adopt enhanced building codes and develop plans for
disaster response and recovery by providing a higher federal cost share, affording
access to additional grants or loans, or offering tax credits or discounts on
insurance premiums.
3. Require that federally owned or leased buildings adopt and enforce hazard-
resilient building codes. Congress could enhance the federal statute that requires
federally owned or leased buildings to adopt the most recent I-Codes. Doing so
would require the federal government to develop more hazard-resilient codes,
because the 2021 edition of I-Codes are only hazard resistant (i.e., the codes may
not ensure a building can be occupied and can function immediately after a
disaster). Alternatively, Congress could amend the statute to require that federally
owned or leased buildings adopt the 2021 I-Codes for Risk Category IV
buildings, such as hospitals, which must be able to be occupied and functional
during and after a disaster.

45 NIST, “Earthquake Risk Reduction in Buildings and Infrastructure Program,” at https://www.nist.gov/programs-
projects/earthquake-risk-reduction-buildings-and-infrastructure-program; NIST, “National Windstorm Impact
Reduction Program Office,” at https://www.nist.gov/el/materials-and-structural-systems-division-73100/national-
windstorm-impact-reduction-program-nwirp; and NIST, “Community Resilience Program,” at https://www.nist.gov/
programs-projects/community-resilience-program.
Congressional Research Service

14

link to page 14 link to page 14 Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

4. Mount an education campaign to create public awareness about and a
political environment around the value of hazard-resilient buildings, so
hazard-resilient codes would be adopted and enforced. Congress could direct
FEMA and/or NIST to mount an education campaign to create public awareness
about and a political environment around the value of hazard-resilient buildings
to increase the adoption and enforcement of hazard-resilient codes. For example,
FEMA’s Nationwide Building Code Adoption Tracking Portal (discussed in
“FEMA Programs and Activities”) may educate stakeholders or citizens about
how hazard resilient their current building codes are or what type and intensity of
hazard their building codes are designed to resist. FEMA’s Building Code Saves
report (see “FEMA Programs and Activities”) or related informational pamphlets
may explain the value of hazard-resilient building codes.46 Congress could
consider asking FEMA or NIST to continue or expand these efforts to educate
and inform stakeholders and the public about the value of hazard-resilient
buildings.
In addition to considering these options to move forward on the recommendations in the IO and
FRT reports, Congress has seen bills introduced to increase the number of hazard-resilient
buildings nationwide. For example, the Disaster Savings and Resilient Construction Act of 2021
(H.R. 1984) would allow a tax credit through 2023 for certain residential or commercial buildings
in a disaster area that are designed and constructed to meet resilient construction requirements.
The legislation defines resilient construction requirements as the ability to provide primary
functions after a disaster, to reduce the magnitude and duration of the disruptive event, and to
withstand and recover from the event. The legislation would require that buildings be constructed
following the most recent editions of I-Codes for residential or commercial buildings to receive
the tax credit. In addition, the legislation would require residential construction to meet certain
criteria under the FORTIFIED certifications from the Insurance Institute for Business and Home
Safety for different hazards and commercial buildings to meet certain ratings by the U.S.
Resiliency Council Rating System.47
Independent of the IO and FRT reports but toward the same objectives, Congress has provided
further directions to federal agencies. For example, in the explanatory statement accompanying
the Consolidated Appropriations Act, 2022 (H.Rept. 117-97), Congress directed NIST and NOAA
to improve building design so that buildings are more resistant to weather and climate change
challenges, objectives that may lead to more hazard-resilient buildings. Specifically, under
“Forward-Looking Building Standards” in H.Rept. 117-97, Congress directed NIST and NOAA
to identify “forward-looking climate data” to use for the standard-setting process to aid federal
and nonfederal entities in developing building codes that account for extreme weather events and
other climate change challenges.48

46 In August 2022, FEMA published FEMA, Building Code Adoption Playbook for Authorities Having Jurisdiction,
FEMA P-2196, August 2022, at https://www.fema.gov/sites/default/files/documents/fema_building-codes-adoption-
playbook-for-authorities-having-jurisdiction.pdf. The document provides an overview of building codes, model
building codes, hazard-resistant design standards, and other details that meet some of the objectives of an educational
campaign suggested in the FRT report.
47 See Insurance Institute for Business and Home Safety, “FORTIFIED Construction Standards,” at https://ibhs.org/
fortified/; and U.S. Resiliency Council, “USRC Rating System,” at https://www.usrc.org/usrc-rating-system/.
48 H.Rept. 117-97 calls for climate information about “chronic climate impacts, such as sea level rise, and extreme
weather events, such as hurricanes, floods, and droughts.”
Congressional Research Service

15

Hazard-Resilient Buildings: Sustaining Occupancy and Function After a Natural Disaster

Author Information

Linda R. Rowan

Analyst in Natural Resources Policy

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and
under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not
subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in
its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or
material from a third party, you may need to obtain the permission of the copyright holder if you wish to
copy or otherwise use copyrighted material.

Congressional Research Service
R47215 · VERSION 1 · NEW
16