Reducing Flood Risk and Flood Insurance Premiums for Existing

Reducing Flood Risk and Flood Insurance Premiums for Existing Residential Buildings HSFE60-13-0002 0003 June 2013

Reducing Flood Risk and Flood Insurance Premiums for Existing Residential Buildings

RA7 June 2013 HURRICANE SANDY RECOVERY ADVISORY

Purpose and Intended Audience The Federal Emergency Management Agency (FEMA) deployed the Mitigation Assessment Team (MAT) to observe building damage in New York and New Jersey after Hurricane Sandy This advisory provides information on potential mitigation measures for buildings located in areas subject to coastal flooding that did not incur Substantial Damage during Hurricane Sandy and are not undergoing Substantial Improvement However the information in this advisory may also be useful to homes that incurred Substantial Damage As property owners begin rebuilding it is important for them to not only consider mitigation measures that can reduce their risk for flood damage from a future flood event but also understand how these mitigation measures affect their National Flood Insurance Program (NFIP) flood insurance premiums

The primary audience for this Recovery Advisory is homeowners but it may also be useful for planners contractors and design professionals advising homeowners This

Terminology

The Substantial DamageSubstantial Improvement determination is made by a local official Homeowners should consult a local building official or floodplain administrator to determine whether their local codes and regulations have more restrictive definitions

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 lsquostart of constructionrsquo of the improvement This term includes structures that have incurred lsquoSubstantial Damagersquo regardless of the actual repair work performed

Refer to FEMA P-758 Substantial Improvement Substantial Damage Desk Reference (2010) for more information

advisory describes actions that homeowners can take to reduce future flood damage to their buildings and thereby also reduce their flood insurance premiums Specifically this advisory describes options for elevating the lowest floor of existing homes (see Figure 1)

of 17

Figure 1 The house on the left is in the final stages of being elevated which will result in reduced flood risk and lower flood insurance premiums than the house on the right (Highlands NJ)


Key Issues

Reconstruction of homes damaged during Hurricane Sandy gives building owners the opportunity to implement mitigation measures that will improve flood resistance and lower NFIP flood insurance premiums

Before undertaking a mitigation project it is critical for building owners to understand the requirements of the NFIP and building codes including the requirements related to enclosed areas below the base flood elevation (BFE)(one-percent-annual-chance [100-year] flood level)

In some situations repairs to damaged homes will be required to meet the construction requirements of the NFIP and the communityrsquos floodplain ordinance and building code

This Recovery Advisory Addresses

Key NFIP requirements Communities in New Jersey and

Moving a buildingrsquos lowest floor to a higher elevation New York State enforce building codes that include requirements

NFIP requirements for enclosures below elevated buildings for buildings in flood hazard areas Special considerations for elevated buildings in Zone V Learn more about applicable codes

by checking with your local building Elevating mechanical electrical and plumbing systems to department

appropriate levels

Useful Links and Resources

Key NFIP Requirements Communities that participate in the NFIP are required to adopt and enforce local regulations that apply to new construction and buildings undergoing Substantial Improvement located in areas mapped as Special Flood Hazard Areas (SFHAs) The NFIP establishes minimum criteria and design requirements specifying how structures are to be constructed in order to minimize the potential for flood damage A primary requirement is that buildings must be elevated to or above the BFE Building owners can determine whether buildings are located within an SFHA by talking to a local floodplain administrator or building official and reviewing the Flood

Insurance Rate Map (FIRM) which shows the extent of the SFHAs and the BFEs For more information on NFIP

Terminology maps refer to the Hurricane Sandy Recovery Advisory Special Flood Hazard Area (SFHA) Land areas No 5 Designing for Flood Levels Above the BFE After subject to a 1 percent or greater chance of Hurricane Sandy (2013) flooding in any given year These areas are

Following large storm events such as Hurricane Sandy indicated on FIRMs as Zone AE A1-A30 A99

FEMA may publish Advisory Base Flood Elevation (ABFE) AR AO AH V VO VE or V1-30 Mapped zones

Maps to support recovery and improve future resiliency outside of the SFHA are Zone X B C or D

Communities must use ABFEs when designing recovery Base Flood Elevation (BFE) Elevation of or mitigation activities funded using FEMA grants flooding including wave height and runup (eg Public Assistance or Hazard Mitigation Grants) having a 1 percent chance of being equaled Recipients of the US Department of Housing and or exceeded in any given year (also known Urban Development (HUD) Community Development as ldquobase floodrdquo and ldquo100- year floodrdquo) BFEs Block Grants must use the ABFE plus 1 foot are the basis of insurance and floodplain

Before beginning any construction it is important management requirements and are shown on that building owners verify with their local building FIRMs department that they have all the State and local

Flood Insurance Rate Map (FIRM) A map permits required to do the project Mitigation projects produced by FEMA to show flood risk The such as those described in this advisory may result in SFHA and BFE are both shown on FIRMs the local building department making a determination FIRMs can be obtained at httpwwwmsc that the home is being Substantially Improved femagov Buildings determined by a building official or floodplain

Page 2 of 17

Reducing Flood Risk and Flood Insurance Premiums for Existing Residential Buildings HSFE60-13-0002 0003 June 2013 Page 3 of 17

administrator to have incurred Substantial Damage or to be undergoing Substantial Improvement are treated as new construction and must be brought into full compliance with the flood provisions of current building codes local floodplain ordinances and NFIP regulations

ABFEs

FEMA recommends that communities apply the ABFEs to new construction homes undergoing Substantial Improvement and repairs to homes that incurred Substantial Damage to ensure that all recovery construction is built stronger safer and less vulnerable to future flooding events Freeboard may be added to the ABFE or the effective BFE as required by the jurisdiction

Post-Hurricane Sandy ABFE maps are available for parts of New York and New Jersey at httpwwwregion2coastalcomsandyabfe FIRMs for all other areas are available at httpsmscfemagov

NFIP Minimum Criteria and Performance Requirements

NFIP criteria specify how new buildings should be constructed in order to minimize the risk of flood damage Building codes include similar requirements

Zone A Table 1 summarizes some of the key Area of Moderate Wave Action (MoWA) NFIP requirements for new construction in Zone The area of Zone A subject to coastal waves A which includes all zones shown on Flood during the base flood delineated by the Limit Insurance Rate Maps (FIRMs) as Zones A AE of Moderate Wave Action (LiMWA) also called A1-A30 AR AO and AH Coastal A Zone in some publications Although

Zone V Table 2 summarizes some of the key the MoWA designation does not currently affect NFIP requirements for new construction in Zone flood insurance premiums FEMA recommends V which includes all zones shown on Flood that communities apply more stringent Insurance Rate Maps (FIRMs) as Zones V VO requirements in this area such as applying Zone VE or V1-30 FEMA recommends applying Zone V V requirements in order to reduce flood damages requirements to buildings in the Area of Moderate caused by wave action Even when not required Wave Action (MoWA) by the local jurisdiction FEMA recommends that

homeowners with property located in these areas The information in Tables 1 and 2 are discussed should mitigate using the Zone V requirementsin greater detail in subsequent sections of this Recovery Advisory

Table 1 Key NFIP Building Design Requirements for Buildings Located in Zone A

Provision Requirement

Building and foundation must be designed constructed and adequately Design and Construction anchored to prevent flotation collapse and lateral movement resulting 44 CFR 603(a)(3)(i) from hydrodynamic and hydrostatic loads including the effects of

buoyancy

Lowest Floor Elevation 44 CFR 603(c)(2) Top of lowest floor (including basement) must be at or above the BFE

Flood Damage-Resistant Materials Structural and nonstructural building materials below the BFE must be 44 CFR 603(a)(3)(ii) flood damage-resistant

Enclosures are permitted only for parking of vehicles building access Enclosures and storage Each enclosure must have a minimum of two flood 44 CFR 603(c)(5) openings on different walls to allow passage of floodwaters

Utilities and equipment must be located (elevated) at or above the BFE Utilities or designed to prevent floodwaters from entering and accumulating in 44 CFR 603(a)(3)(iv) components during the base flood


Table 2 Key NFIP Building Design Requirements for Buildings Located in Zone V


Building and open foundation must be designed constructed and Design and Construction adequately anchored to prevent flotation collapse and lateral movement 44 CFR 603(a)(3)(i)603(e)(4) due to simultaneous wind and flood loads including the effects of

buoyancy

Lowest Floor Elevation and Foundations Bottom of the lowest horizontal structural member of the lowest floor 44 CFR 603(e)(4) must be at or above the BFE and elevated on pilings or columns


Enclosures are permitted only for parking of vehicles building access

Enclosures 44 CFR 603(e)(5)

and storage Walls must be designed to collapse (break away) under flood loads to allow free passage of floodwaters without damaging the structure or supporting foundation system Utilities and equipment must not be mounted on or pass through breakaway walls


When determining the appropriate building design requirements homeowners in a Zone A should consider that in the event that an area is remapped as Zone V they may be subject to higher flood insurance premiums

Additional Considerations Related to Flood Insurance Premiums

NFIP premiums are tied to compliance with the criteria described in Tables 1 and 2 In addition to meeting those requirements building owners need to consider a variety of other factors An important factor is to understand which floor meets the definition of ldquolowest floorrdquo One of the largest contributors to an NFIP flood insurance premium is the designation of the ldquolowest floorrdquo and how high it is compared to the BFE Before beginning any mitigation project building owners should review the NFIP Elevation Certificate and Instructions1 in order to understand the many factors that influence how the ldquolowest floor elevationrdquo of a building will be designated

When considering implementing a mitigation measure it is important to remember that the house must resist multiple hazards Buildings must be able to resist the effects of wind and water loads acting simultaneously (where applicable seismic loads must also be addressed)

Communities may require buildings in the SFHA to be elevated higher than the BFE or ABFE if adopted The addition of height above the BFE expressed in feet is referred to as a freeboard requirement While the addition of freeboard is not required by the NFIP minimum standards it does result in significantly lower flood insurance rates due to reduced flood risk FEMA recommends the addition of at least 1 or 2 feet of freeboard to account for uncertainties future development and floods higher than the base flood The reduction of insurance premiums related to the addition of freeboard depends on the height of the lowest floor above the BFE the flood zone in which the home is located and other factors

Another consideration is that NFIP flood insurance policies have limits on coverage of contents in enclosures under elevated buildings Designers contractors and owners may wish to contact a qualified insurance agent or the NFIP for more information about policy coverage coverage limits and costs Homeowners should consult their insurance provider about what discounts may be available

FIRMs are a ldquosnapshotrdquo of conditions at the time the maps were developed Future conditions may result in higher flood elevations Refer to Hurricane Recovery Advisory No 5 Designing for Flood Levels above the BFE after Hurricane Sandy for more information on this and on how the recently passed Biggert-Waters Flood Insurance Reauthorization Act in 2012 may affect your property

1 Elevation Certificate available at httpswwwfemagovlibraryviewRecorddoid=1383

Page 4 of 17


Moving a Buildingrsquos Lowest Floor to aHigher Elevation As shown in Tables 1 and 2 the lowest floor of a building (for Zone A) or the bottom of the lowest horizontal structural member (for Zone V) must be elevated to or above the BFE to be eligible for lower flood insurance premiums Additionally any enclosed area beneath the elevated lowest floor must meet certain physical and usage requirements as described in NFIP criteria

There are several ways to modify an existing home to elevate the lowest floor Table 3 provides a broad overview of the mitigation measures described in this section and allows a comparison by building type (detached or attached) flood zone relative cost and the level of difficulty associated with undertaking the project Refer to FEMA P-312 Homeownerrsquos Guide to Retrofitting (2009) for other mitigation measures that may be available

Terminology

Per the FEMA Flood Insurance Manual (2013)

Elevated Building ldquoA building that has no basement and has its lowest elevated floor raised above ground level by foundation walls shear walls posts piers pilings or columns Solid perimeter foundation walls are not an acceptable means of elevating buildings in Zone V and Zone VErdquo

Lowest floor ldquoThe lowest floor of the enclosed area (including a basement) An unfinished or flood-resistant enclosure usable solely for parking of vehicles building access or storage in an area other than a basement area is not considered a buildingrsquos lowest floor provided that such enclosure is not built so as to render the structure in violation of [NFIP] requirementsrdquo

Basement ldquoAny area of the building including any sunken room or sunken portion of a room having its floor below ground level (subgrade) on all sidesrdquo

Some of the measures described in this advisory may be difficult to perform on small lots or for buildings that are in close proximity to adjacent buildings so the specifics of the lot and the building must be considered carefully when selecting the preferred mitigaton measure Projects that require large amounts of space for equipment access or temporary relocation of a building may not be feasible on a given site pursuing such a project on an unsuitable lot or building may result in a project that is more complicated and expensive than necessary If small lots and equipment access problems make an individual elevation project more difficult and expensive it may be prudent to consider elevating multiple buildings at the same time

Regardless of the type of building construction the NFIP requirements for the area below the BFE (described in subsection ldquoNFIP Requirements for Enclosed Areas Below the BFErdquo of this advisory) must be followed in order to have the NFIP designate the floor above the BFE as the buildingrsquos ldquolowest floorrdquo for flood insurance rating purposes

Table 3 Mitigation Measures for Elevating the Lowest Floor of a Building

Mitigation Measures Building Type Flood Zone

Cost Project Difficulty Detached

(Free Standing) Attached Zone A Zone V

Convert ground floor (to NFIP-compliant space)

Fill basement

Elevate the Building

Not recommended $ - $$ Easy

$ Easy

Lowest floor of row Not applicable Not recommended $$$$ Hard house

Slab-on-grade Not recommended $$$ Moderate

Crawlspace $$ Moderate

Consider using an open foundation consistent with Zone V requirements for building located in a MoWA area according to the ABFE maps

Only recommended on open foundations that are free of obstructions and sufficient to resist scour and erosion

One dollar sign indicates a less expensive option and four dollar signs indicate the most expensive option

Options for attached homes such as duplexes and townhomes are complicated unless all owners elect to undertake mitigation actions together

Page 5 of 17


Converting the Ground Floor and Filling Below-Grade Areas and Basements

One way to achieve a lowest floor above the BFE in an existing building in the SFHA is to convert the ground floor to an NFIP-compliant space or fill the basement area of a building (see subsection titled ldquoAdditional Information on Filling a Basementrdquo) These actions require moving all the living space and necessary electrical heating plumbing and air conditioning equipment above the BFE (Figure 2) While

WARNING When hiring a design these actions result in a loss of living space the reduction professional (typically an engineer or in NFIP insurance premiums may be sufficient to offset architect) the design professional should the inconvenience and any loss of building value To be registered (or licensed) in the State in compensate for the lost living space it may be possible which the work is being performed to remove the existing roof and construct another story

above the existing building or finish an unfinished attic area Homeowners should consult with the community to see if this is permitted and with an engineer or architect to help develop options and determine feasible cost-effective solutions

Converting the ground floor The criteria for converting the ground floor depends whether the home is located in Zone A or Zone V

Zone A When converting a ground floor to compliant space (or filling a below-grade area or basement) a registered design professional must certify that the design and methods of construction specified for retrofitting the foundation walls are in accordance with accepted standards of practice for meeting the following provisions

The foundation and structure attached must be anchored to resist flotation collapse and lateral moveshyment resulting from the effects of base flood water loads acting on building components below the BFE

The potential for scour and erosion at the foundation must be anticipated for conditions associated with the base flood including wave action

The walls below the BFE and supporting the structure must be constructed using flood damage-resistant materials

The walls of the enclosed space below the BFE must contain flood openings that will allow the automatic entry and exit of floodwaters such that they comply with NFIP criteria See FEMA Technical Bulletin 1 Openings in Foundation Walls and Walls of Enclosures (2008)

The building must meet the definition of an elevated building per the FEMA Flood Insurance Manual (2013)

The use of space below the BFE must be restricted to parking of vehicles building access and storage

Repurposing a ground floor living space and converting it to an NFIP-compliant space may appear to be a simple solution to reduce flood insurance premiums While this type of mitigation in some instances may require only minimal remodeling of the house it should be verified by a design professional that it is an appropriate mitigation measure and that the walls for the ground floor are properly anchored and able to resist the loading associated with the new reconfiguration of the space Some walls may act as foundation walls for the house so is important to document that the ground floor walls have been evaluted by a design

Figure 2 In Zone A the floor below the BFE (left) can be modified to be compliant with NFIP criteria (right)

Page 6 of 17


professional and that any necessary modifications to the walls have been constructed properly

Figure 3 provides an example of a foundation wall design certification statement that can be signed by a registered design professional to certify their design and methods of construction meet the above provisions A design professional may also use the ldquoFEMA Floodproofing Certificate for Non-Residential Structuresrdquo (FEMA Form 086shy0-34) (FEMA 2012)2 to certify a floodproofing design for a nonshyresidential building that is allowed as an alternative to elevating above the BFE

The type of foundation affects flood insurance premiumsmdash open foundations (piles columns piers posts) and certain wall systems (masonry and concrete walls shear walls) result in lower premiums than typical wood-framed walls Typical wood-framed walls do not meet the Flood Insurance Manual (FIM) definition of a foundation wall and therefore buildings with wood-framed Figure 3 Sample foundation wall design certification statement

walls are not eligible for lower flood insurance premiums even if the ground floor is converted to NFIPshy WARNING Strengthening compliant space With wood-framed walls the lowest floor elevation wood-framed walls that are would still be assessed as the floor of the converted space (Figure 2) To below the BFE will not result determine whether replacing wood-framed walls as part of a mitigation in reduced flood insurance project is cost-effective compare the construction costs with the premiums resulting annual reduction in insurance premium costs over the course of the usable life of the building

In Zone A a possible alternative to replacing wood frame walls below the BFE with concrete or masonry is to use a combination of wood shear walls and columns or posts to make the foundation consistent with the FIM definitions of ldquoelevated buildingrdquo and ldquofoundation wallrdquo Shear walls are walls that are designed to resist lateral (side-to-side) loads associated with floodwaters wind and earthquake forces Shear walls must be oriented parallel to the direction of the moving floodwaters to be considered compliant It is important to consult a registered design professional such as a structural engineer before undertaking such a project The existing wood-framed walls may need to be modified so they can resist all lateral and vertical loads (due to gravity or uplift from the wind) and a registered design professional will need to evaluate whether the load capacity of the wall needs to be increased by adding additional structural sheathing (eg plywood sheathing) additional studs wood blocking anchors fasteners or structural connectors

Building code requirements may also require that fire protection mdash such as gypsum boards (drywall) be incorporated into the design Walls below the BFE with gypsum board would have to be constructed using

2 FEMA Form 086-0-34 is available at httpwwwfemagovlibraryviewRecorddoid=1600

Page 7 of 17


paperless gypsum boards The design professional should also inspect the concrete slab and footings to verify that they are capable of withstanding the loads that the shear walls must transfer to them

In order to make the modified foundation compliant the walls oriented perpendicular to the direction of flood flow must be converted to a series of beams supported by columns or posts A beam spanning between the shear walls must carry accumulated loads to the columns or posts which must be properly anchored to the slab or footing to maintain the load path for the house Figure 4 illustrates an example of a three-story house where the ground level walls have been converted to a series of shear walls posts and beams All the wall sections posts and columns below the BFE must be constructed entirely of flood damage-resistant materials

The shear wall and post foundation system shown in this figure is not allowed in homes undergoing Substantial Improvement or post-FIRM Zone V homes

Figure 4 Before and after of a house with the lower floor converted using a shear wall and post foundation system

WARNING If a homeowner retrofits an existing house using the wood shear wall concept discussed in this section the NFIP insurer will require the property owner to sign and submit a non-conversion agreement as part of the flood insurance application The agreement will state that the owner acknowledges 1) any enclosed space below the lowest elevated floor can be used only for parking building access or storage 2) the enclosed space must be unfinished and must be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of flood waters A minimum of two openings must be provided with positioning on at least two walls having a total net area of not less than 1 square inch per every square foot of enclosed area and 3) flood insurance offers limited coverage for flood damage to the enclosure and any contents located below the lowest elevated floor of an elevated post-FIRM building located in the SFHA Owners should consult with their insurance agent for specific agreement language acceptable to the NFIP insurer

Page 8 of 17


and any enclosed area below the BFE must meet all the NFIP requirements for an enclosure Documentation of the modifications to the wood-framed wall system should be kept by the homeowner and future owners should be made aware of the restrictions on the space so they do not attempt to convert the space into a living area

Zone V Buildings located in Zone V are required to have an open foundation that allows floodwater and waves to pass beneath the elevated structure and be free of obstructions Property owners should refer to the subsection titled ldquoElevating Buildings in Zone V Areasrdquo for a discussion of compliant mitigation measures in Zone V and to FEMA Technical Bulletin 5 Free-of-Obstruction Requirements for Buildings Located in Coastal High Hazard Areas in accordance with the National Flood Insurance Program (2008) for information on NFIP requirements in Zone V

Additional information on filling a basement The criteria for filling a basement is the same for homes located in Zone A and Zone V except for a few exceptions The presence of a basement may result in very high flood insurance premiums and extremely limited coverage by the flood policy Insurance premiums can be significantly reduced by filling the basement using gravel and soil and modifying the remaining space above the fill to meet the NFIP requirements for enclosures below the BFE The fill should be at least up to the adjacent grade (ground) level If a future elevation of the house is likely it is much better to elevate before filling the basement to avoid complications with the elevation project Also although filling a basement will likely result in lower insurance premiums other retrofits may also be necessary to maximize premium reductions

It is important to plan for proper drainage when filling a basement If fill is placed on top of the original basement slab any water that enters the area may be trapped within the original basement and have no way to drain To provide drainage the basement slab can be broken up or drain holes or trenches can be cut through the slab A registered design professional may recommend a system of underdrains be installed to improve drainage

It can be difficult for a contractor to properly compact fill placed in an existing basement because mobilizing and using compaction machinery can be difficult in a confined space Therefore some settlement of fill should be expected after initial placement Additional fill may be required to maintain the required fill level in the basement after the initial fill has settled

The above described information pertains to both Zone A and Zone V but the following additional requirements pertain to Zone V Buildings located in Zone V are required to have an open foundation and be free of obstructions Basements in Zone V should only be filled to ground or grade-level Mitigation projects in Zone V that result in a continuous wall foundation or fill above-grade may be considered an obstruction Property owners should refer to the subsection titled ldquoElevating Buildings in Zone V Areasrdquo for a discussion of compliant mitigation measures in Zone V


Elevating a building involves raising it so that the lowest floor is at or above the BFE Elevating typically involves separating the building from its foundation constructing a new higher foundation and reattaching the building to the new foundation For more information on the elevation process refer to FEMA P-312 Homeownerrsquos Guide to Retrofitting (2009)

The type of new foundation is dictated by a number of factors including the flood zone in which the building is located soil conditions at the site and the design and construction of the house For information on how high to elevate buildings refer to Hurricane Sandy Recovery Advisory No 5 Designing for Flood Levels Above the Base Flood Elevation (FEMA 2013)

Row houseTownhouse Row houses have been constructed in New York and New Jersey since the late nineteenth century Many of these buildings consist of a lower level or walk-out basement that is not below grade on all sides (sometimes referred to as a garden apartment) which is not classified as a basement per NFIP criteria and two to three stories of upper floors

Page 9 of 17


Zone A To achieve lower flood insurance premiums it may be necessary to convert the lowest level to NFIP-compliant space and modify the upper floors If the floor above the lowest floor is also below the BFE it will need to be raised and reconstructed to the appropriate elevation (Figure 5) If row houses have higher ceilings typical of older construction it may be possible to raise the floor while retaining the original floor space of the upper levels but with lower ceiling heights (Figure 6) In such situations walls at the front and rear of the building can probably be modified to raise windows as needed In more modern townhomes it may be possible to convert the lowest floor to NFIP-compliant space and make adjustments or repurpose the upper floors Uses appropriate for areas below the BFE are described in the subsection ldquoUse of Enclosed Areasrdquo of this Recovery Advisory

Zone V Buildings located in Zone V are required to have an open foundation and be free of obstructions Property owners should refer to the subsection titled ldquoElevating Buildings in Zone V Areasrdquo for a discussion of compliant mitigation measures in Zone V

Slab-on-grade houses Although slab-on-grade houses may be difficult to raise a number of options exist with regard to raising the structure with the slab or without the slab in which case a new floor system must be provided

Zone A There are two common options for elevating a house where the first floor of the living space is on a slab (1) cut the walls away from the slab raise the house extend the foundation walls andor foundation piers upward and construct a new wooden floor system (Figure 7) or (2) elevate the whole house including the concrete slab and then construct the new foundation under the slab Due to unknown design variables associated with elevating a house with the slab attached the first option of constructing a new floor system is generally preferred

Figure 5 A row house with the floor levels being elevated in order to maximize living area above the BFE

Figure 6 Elevation of a floor system in a row house The old floor joist system (red circle) was removed and the gaps left by the joists filled The new floor joist system (red arrow) designed by an engineer was installed at a higher elevation (Brooklyn NY)

Page 10 of 17


Figure 7 Mitigating a slab-on-grade house by elevating an existing wood-frame house without the slab using a new wood truss floor system (Source FEMA P-259 Figure 5E-18)

Figure 8 illustrating option 1 shows a completed slab-on-grade elevation project with the walls separated from the poured slab (which remains on the ground) and a new wood-framed floor system added

Zone V Buildings located in Zone V are required to have an open foundation and be free of obstructions Should a property owner decide to elevate a slab-on-grade house in Zone V foundation walls should not be used In order to reduce flood damage and receive a reduction in flood insurance premiums the foundation must be an open foundation constructed from piers piles posts or columns If the original slab is left in place a registered design professional should develop construction details to prevent the slab from damaging the new foundation during a flood event Refer to the subsection titled ldquoElevating Buildings in Zone V Areasrdquo for a discussion of compliant mitigation measures in Zone V

Houses with crawlspaces Houses on crawlspace foundations are generally the easiest and least expensive houses to elevate They are usually one- or two-story houses built on masonry or concrete crawlspace walls The crawlspace allows access to place the steel beams under the house for lifting and raising the house with a series of jacks Outside equipment such as air conditioning compressors will need to be elevated and duct work in the crawlspace will likely need to be replaced during the process

Figure 8 This house in Zone A was detached from its slab foundation (which remains) and elevated on masonry piers The floor system is supported by new wood joists (Mandeville LA)


Zone A To achieve the necessary height the foundation walls that form crawlspaces can be replaced or extended A new foundation of either a continuous masonry or poured concrete walls is constructed along with higher interior piers Although minimum Zone A requirements only require the top of the lowest floor to be at the BFE additional elevation is usually relatively inexpensive compared to attempting to protect ductwork and insulation that may be present under the floor system Rather than separately relocating utility equipment it is generally less expensive to increase the elevation of the lowest floor high enough that the under-floor ductwork is above the BFE

Zone V In Zone V free-of-obstruction open foundations must be used if the homeowner intends to reduce damages and reduce flood insurance premiums These open foundation designs should be prepared by an engineer or architect After a home is elevated and the old crawlspace walls (and slab) are demolished a new foundation of reinforced masonry columns or poured concrete columns can be constructed (Figure 9) Open foundations are described in the subsection titled ldquoElevating Buildings in Zone V Areasrdquo On large lots houses can be temporarily shifted while piles are installed and then moved back and attached at the top of the new pile foundation Small lots or limited access may require the house to be elevated in place (see subsection on ldquoConstructing open foundations on small lotsrdquo) For additional information about constructing open foundations on small lots refer to Hurricane Sandy Fact Sheet No 2 Foundation Requirements and Recommendations for Elevated Homes (2013)

Elevating Buildings in Zone V Areas

NFIP regulations do not allow use of closed foundation walls (eg crawlspace) in Zone V areas Open foundationsmdashpiles piers or columnsmdashare necessary because the reduced surface area of the open foundation allows water waves and debris to pass under buildings minimizing the forces exerted against the foundation components Foundation performance in coastal areas subject to high velocity floodwaters and wave action improves significantly when foundation piles are deeply embedded Pile foundations may be of wood concrete or steel driven to a depth such that the strength of the foundation is not compromised by the erosion and scour common with coastal storm events (for more information on scour and erosion refer to section 3112 of FEMArsquos Hurricane Ike in Texas and Louisiana Mitigation Assessment Team Report (2009) and FEMA P-55 Coastal Construction Manual [2011])

Constructing open foundations on small lots Small lots with limited access for construction equipment may make it difficult to drive normal length pilings The alternative is to use pier or column foundations that are designed for wave conditions and are deep enough to adequately resist loads after scour and erosion occur Piles may be required to support the foundation since shallow pier and column foundations may not be sufficient to resist the flood loads if large amounts of scour and erosion occur

Foundation retrofits to homes located in Zone V are more challenging than for those in Zone A because of the additional loads from waves and high velocity water The elevation process must provide enough space to install a foundation sufficient to resist these increased flood loads To create the needed space the home is first detached from its foundation and then lifted and placed on temporary supports called cribbing Micropiles or helical piles are then installed in the ground as foundation elements Poured concrete columns and grade beams (an at- or below-grade system of beams between columns) are then installed on top of and connected to the micropiles or helical piles Geotechnical or soils engineers should be consulted to design foundations that incorporate micropiles or helical piles Micropiles or helical piles can be used to provide the

Figure 9 A house in the final process of being elevated in Zone A The columns have been poured and the cribbing and steel lifting beams will be ready to be removed soon (Highlands NJ)

Page 12 of 17


additional lateral support needed to make the foundation successful A benefit of using them is that they can be installed with minimal site access and in areas with the low vertical clearances expected when a house is elevated in place Proper foundation designs for open foundations on small lots will require the expertise of both a geotechnical and a structural engineer For additional information about open foundations and building on small lots refer to the Hurricane Sandy Fact Sheet Open Foundation Requirements for Elevated Homes (2013)

NFIP Requirements for Enclosed Areas below the BFE While the main portions of elevated buildings are above the BFE the foundation and any enclosed areas below the BFE are exposed to base flood forces An overview of the key NFIP design requirements for buildings is provided in Tables 1 (Zone A) and 2 (Zone V) The following is a more detailed explanation of some of the key requirements and some information necessary to obtain the lowest insurance premium

Use of Enclosed Areas

The NFIP insurance and building design regulations specify that enclosed areas below the BFE can only be used for

Parking of vehicles (attached garages or parking areas below elevated buildings)

Building access (stairwells foyers elevators)

Storage (low-value items)

Installing utility stub-outs (ie purposely placed utility access points for future connections) is inconsistent with the allowable uses of an unfinished enclosed area

It is important to understand how an otherwise compliant area below the BFE can be rendered non-compliant by installing features that are inconsistent with the limitations on use If the use changesmdashfor instance if a bathroom is installed or the area is converted to a bedroommdashthe floor of the enclosure becomes the ldquolowest floorrdquo of the building and will result in significantly higher flood insurance premiums

In order to verify that the use of the space below the BFE is consistent with NFIP criteria it may be necessary to use a ldquonon-conversion agreementrdquo which is a deed restriction stating that the property owner will maintain the structure in accordance with the floodplain management criteria set forth in Title 44 of the Code of Federal Regulations (CFR) Part 603 and local floodplain ordinances for the life of the property The non-conversion agreement is binding to future owners heirs successors personal representatives and assignees Failure to maintain compliance with NFIP criteria could jeopardize the flood insurance policy on the home and the potential for Federal disaster assistance should the home be damaged during a hazard event

Flood Damage-Resistant Materials

Careful attention to compliance with the NFIP regulations for flood damage-resistant materials is important during design plan review construction and inspection Compliance influences the buildingrsquos vulnerability to flood damage the cost of flood insurance and the buildingrsquos ability to recover after a flood event

Flood damage-resistant materials In all flood zones every part of a building that is below the BFE is susceptible to flooding during the base flood The NFIP regulations require the use of flood damage-resistant building materials (refer to text box) For more information see FEMA Technical

Terminology

Per FEMA Technical Bulletin 2 Flood Damage-Resistant Materials Requirements for Buildings Located in Special Flood Hazard Areas (2008)

Flood damage-resistant material Any building product [material component or system] capable of withstanding direct and prolonged contact with floodwaters without sustaining significant damage Prolonged contact At least 72 hours

Significant damage Damage requiring more than cosmetic repair

Cosmetic repair Cleaning sanitizing and resurfacing (eg sanding repair of joints repainting) of the material The cost of cosmetic repair should also be less than the cost of replacement of affected materials and systems

Page 13 of 17


Bulletin 2 Flood Damage-Resistant Materials Requirements for Buildings Located in Special Flood Hazard Areas (2008) and FEMA Technical Bulletin 8 Corrosion Protection for Metal Connectors in Coastal Areas for Structures Located in Special Flood Hazard Areas in accordance with the National Flood Insurance Program (1996) As defined in Table 1 of FEMA Technical Bulletin 2 only Class 4 materials (resistant to floodwater damage from wetting and drying but less durable when exposed to moving water) and Class 5 materials (highly resistant to floodwater damage including damage caused by moving water) are acceptable for use below the BFE

Finished interiors Finishing the interior of enclosures with drywall or other finish materials is not permitted unless required to address life-safety and fire code requirements NFIP flood insurance will not pay a claim for finish materials located in basements or in enclosed areas below elevated buildings even if those materials are considered to be flood damage-resistant

Flood Openings

NFIP requirements related to flood openings apply only to buildings in Zone A that have enclosed areas below the elevated building If enclosure walls are not equipped with flood openings to relieve the pressure of standing or slow-moving water against them (treated as hydrostatic loads3) the walls can be damaged or fail during a flood Figure 10 illustrates the placement of flood openings in a typical crawlspace foundation wall For additional information on crawlspace construction refer to FEMA Technical Bulletin 11 Crawlspace Construction for Buildings Located in Special Flood Hazard Areas (2001)

Compliance with the NFIP regulations for flood openings is critical If openings are not compliant and the bottom of the crawlspace is below grade on all four sides the bottom of the crawlspace or the floor of the enclosure becomes the ldquolowest floorrdquo resulting in significantly higher flood insurance premiums

FEMA Technical Bulletin 1 Openings in Foundation Walls and Walls of Enclosures (2008) explains the NFIP requirements for flood openings and provides guidance for prescriptive (non-engineered) openings and engineered openings Non-engineered openings are required to have 1 square inch of net open area for every square foot of enclosed area As an alternative engineered openings that have characteristics that differ from non-engineered openings may be used provided they are designed and certified by a registered design professional as meeting certain performance characteristics described in Technical Bulletin 1

Walls below the BFE in Zone A

According to the NFIP Flood Insurance Manual (FEMA 2013) buildings located in Zone A should have the lowest floor raised above ground level on foundation walls shear walls posts piers pilings or columns Although new homes may be elevated on earthen fill use of fill to elevate existing homes is rare To be recognized by NFIP flood insurance as an elevated building foundation walls should be constructed of masonry or concrete up to the BFE The following definitions are used by the NFIP when determining the ldquolowest floor elevationrdquo for flood insurance purposes

Foundation Walls Masonry walls poured concrete walls or precast concrete walls regardless of height that extend above grade and support the weight of a building

Figure 10 Flood opening in typical crawlspace foundation (adapted from FEMA P-259 Figure 5E-13)

If unequal higher grade governs

Note Flood-resistant materials and methods required below DFE

3 For engineering practicality it is assumed that slow-moving water is hydrostatic until it surpasses a certain speed

Page 14 of 17


Solid Perimeter Foundation Walls Walls that are used as a means of elevating a building in Zone A areas and that must contain sufficient openings to allow for the unimpeded flow of floodwaters more than 1 foot deep

Shear Walls Walls used for structural support but not structurally joined or enclosed at the ends (except by breakaway walls) Shear walls should be parallel or nearly parallel to the flow of the water and can be used in any flood zone (Note that this definition is different than that typically used by structural engineers or other design professionals)

Failure to meet the strict definitions associated with the NFIP Flood Insurance Manual may result in the ldquolowest floor elevationrdquo on the FEMA Elevation Certificate not reflecting the planned lowest floor of the living area thereby resulting in higher flood insurance premiums

Buildings in Zone A elevated on walls should have a distinct footing underneath the foundation wall If the at-grade or ground floor of a wood-framed building is converted to NFIP-compliant space it may be beneficial to replace the wood-framed walls with masonry or concrete foundation walls piers or columns up to the BFE because they are more damage resistant and may result in lower flood insurance premiums (as described in the subsection titled ldquoConverting the Ground Floor and Filling Below-Grade Areas and Basementsrdquo) This may require installing temporary cribbing or shoring so that the new foundation can be constructed The new foundation should be properly anchored into the footing In order to make the proper connection between the new foundation and the footing additional measures may be needed These measures requiring professional design may include a short cripple wall or wood-framed wall to be constructed between the top of the masonry or concrete wall and the wood-framed building above For more information on maintaining a continuous load path refer to Hurricane Sandy Recovery Advisory No 1 Improving Connections in Elevated Buildings (2013) and FEMA P-499 Home Builderrsquos Guide to Coastal Construction (2010) Fact Sheets 41 42 and 43

Additional Considerations for Elevated Buildings in Zone V

For buildings located in Zone V the NFIP requires that all new buildings and those undergoing Substantial Improvements have the bottom of the lowest horizontal structural member of the lowest floor elevated to or above the BFE on open foundations (pilings piers or columns) that allow floodwaters and waves to pass underneath Based on NFIP loading and obstruction requirements solid perimeter foundation walls and shallow foundations (such as continuous or spread footings) are not acceptable foundations Buildings with obstructions that prevent the free flow of coastal floodwaters will have higher flood insurance rates than buildings considered free of obstructions

Obstructions below the BFE For compliance with the NFIP and to obtain lower flood insurance premiums the area under elevated Zone V buildings should be free of obstructions FEMA Technical Bulletin 5 Free-of-Obstruction Requirements for Buildings Located in Coastal High Hazard Areas in accordance with the National Flood Insurance Program (2008) provides specific guidance concerning the NFIPrsquos free-of-obstruction requirements in Zone V as well as the general requirements for construction that will minimize flood damage potential in Zone V construction For flood insurance rating purposes an area is considered to be free of obstructions only if all of the following apply

No solid walls of any kindmdashincluding breakaway wallsmdashbelow the BFE (insect screening open lattice and open slats are not considered obstructions elevator shafts are allowable)

Stairs below the BFE are open

No machinery or equipment below the BFE Machinery and equipment include items permanently affixed to the structure that provide utility services to the building (eg furnaces water heaters heat pumps air conditioners elevators etc)

Enclosed areas under elevated buildings According to the NFIP regulations areas below elevated buildings in Zone V may be enclosed in one of three ways non-supporting breakaway walls open latticework or insect screening Enclosed elevator shafts are allowable

Page 15 of 17


Use of breakaway walls will increase flood insurance premiums because they are considered obstructions from an insurance perspective Owners should be aware that in some instances prescriptive breakaway walls may not be allowed or appropriate and it may be necessary for a registered design professional to certify the design of the breakaway walls to meet building code requirements (eg for wind loading) Information on breakaway walls can be found in FEMA Technical Bulletin 9 Design and Construction Guidance for Breakaway Walls Below Coastal Buildings (2008)

Lattice can be an effective method to screen areas below the BFE Acceptable types of lattice include

Wooden or plastic lattice with at least 40 percent of its area open and made of material no thicker than frac12 inch

Wooden or plastic slats or shutters with at least 40 percent of their area open and made of material no thicker than 1 inch

Insurance premium considerations Some considerations affecting the rates and costs of NFIP flood insurance include

The presence of an enclosure and its size affect flood insurance premiums substantially higher premiums are charged for enclosures that are 300 square feet or greater in area

The presence of garage doors below an elevated building even if designed in accordance with FEMA Technical Bulletin 9 Design and Construction Guidance for Breakaway Walls Below Elevated Coastal Buildings (2008) may increase the flood insurance premium

Stairs ramps and elevators are permitted but depending on how they are constructed may be considered obstructions for flood insurance rating purposes and result in higher flood insurance premiums

Elevating Mechanical Electrical and Plumbing Systems to Appropriate Levels As shown in Tables 1 and 2 utilities and equipment must be elevated to or above the BFE or designed to prevent floodwaters from entering and accumulating in components during the base flood The NFIP requires buildings that have incurred Substantial Damage or are undergoing Substantial Improvements to have utility systems protected from flood damage using the same criteria required for new construction

Mechanical electrical and plumbing systems in existing buildings can often be effectively protected from flood damage by elevating them The easiest and most practical time to undertake this effort is during construction renovations or repairs Additional information on elevating eq uipment can be found in the Hurricane Sandy Recovery Advisory No 3 Restoring Mechanical Electrical and Plumbing Systems in Non-Substantially Damaged Residential Buildings (February 2013) and in FEMA P-348 Protecting Utilities from Flood Damage (1999)

The FEMA Region II Web page provides useful Useful Links and Resources information and links for

The following resources describe numerous mitigation options with sufficie nt disaster survivors and detail to complete an elevation mitigation project recovering communities

including available FEMA FEMA NFIP Technical Bulletins Available from httpwwwfemagov assistance and recovery national-flood-insurance-program-2nfip-technical-bulletins initiatives Please refer to

gt Technical Bulletin 1 Openings in Foundation Walls and Walls of wwwregion2coastalcom Enclosures (2008)

gt Technical Bulletin 2 Flood Damage-Resistant Materials Requirements for Buildings Located in Special Flood Hazard Areas (2008)

gt Technical Bulletin 5 Free-of-Obstruction Requirements for Buildings Located in Coastal High Hazard Areas in accordance with the National Flood Insurance Program (2008)

gt Technical Bulletin 8 Corrosion Protection for Metal Connectors in Coa stal Areas for Structures Located in Special Flood Hazard Areas in accordance with the National Flood Ins urance Program (1996)

Page 16 of 17


gt Technical Bulletin 9 Design and Construction Guidance for Breakaway Walls Below Coastal Buildings (2008)

gt Technical Bulletin 11 Crawlspace Construction for Buildings Located in Special Flood Hazard Areas (2001)

FEMA Hurricane Sandy Recovery Advisories and Fact Sheets 2013 Available from httpwwwfemagov building-sciencehurricane-sandy-building-science-activities-resources

gt Hurricane Sandy Recovery Advisory No 1 Improving Connections in Elevated Buildings

gt Hurricane Sandy Recovery Advisory No 3 Restoring Mechanical Electrical and Plumbing Systems in Non-Substantially Damaged Residential Buildings

gt Hurricane Sandy Recovery Advisory No 5 Designing for Flood Levels Above the Base Flood Elevation

gt Hurricane Sandy Fact Sheet No 2 Foundation Requirements and Recommendations for Elevated Homes

FEMA P-348 1999 Protecting Utilities from Flood Damage Washington DC Available at httpwwwfema govlibraryviewRecorddoid=1750

FEMA P-312 2009 Homeownerrsquos Guide to Retrofitting Washington DC Available at httpwwwfemagov libraryviewRecorddoid=1420

FEMA P-757 2009 Hurricane Ike in Texas and Louisiana Mitigation Assessment Team Report Washington DC Available at httpwwwfemagovlibraryviewRecorddoid=3577

FEMA P-499 2010 Home Builderrsquos Guide to Coastal Construction Washington DC Available at http wwwfemagovlibraryviewRecorddoid=2138

FEMA P-55 2011 Coastal Construction Manual Washington DC Available at httpwwwfemagov libraryviewRecorddoid=1671

FEMA P-259 2012 Engineering Principles and Practices for Retrofitting Flood-Prone Residential Structures Washington DC Available at httpwwwfemagovlibraryviewRecorddoid=1645

FEMA 086-0-33 2012 National Flood Insurance Program Elevation Certificate and Instructions Washington DC Available at httpwwwfemagovlibraryviewRecorddoid=1383

FEMA 086-0-34 2012 Floodproofing Certificate for Non-Residential Structures Available at httpwww femagovlibraryviewRecorddoid=1600

FEMA 2013 National Flood Insurance Program Flood Insurance Manual Washington DC Available at httpwwwfemagovflood-insurance-manual

For more information see the FEMA Building Science Frequently Asked Questions website at httpwwwfema govfrequently-asked-questions

If you have any additional questions on FEMA Building Science Publications contact the helpline at FEMAshyBuildingsciencehelpfemadhsgov or 866-927-2104

You may also sign up for the FEMA Building Science e-mail subscription which is updated with publication releases and FEMA Building Science activities Subscribe at https publicgovdeliverycomaccountsUSDHSFEMAsubscriber newtopic_id=USDHSFEMA _193

Visit the Building Science Branch of the Risk Reduction Division at FEMArsquos Federal Insurance and Mitigation Administration at httpwwwfemagovbuilding-science

To order publications contact the FEMA Distribution Center

Call 1-800 -480 -2520 (MondayndashFriday 8 amndash5 pm EST)

Fax 240-699-0525

E-mail FEMA-PublicationsshyWarehousefemadhsgov

Additional FEMA documents can be found in the FEMA Library at httpwwwfemagovlibrary

Please scan this QR code to visit the FEMA Building Science Web page

Page 17 of 17


Key Issues

Reconstruction of homes damaged during Hurricane Sandy gives building owners the opportunity to implement mitigation measures that will improve flood resistance and lower NFIP flood insurance premiums

Before undertaking a mitigation project it is critical for building owners to understand the requirements of the NFIP and building codes including the requirements related to enclosed areas below the base flood elevation (BFE)(one-percent-annual-chance [100-year] flood level)

In some situations repairs to damaged homes will be required to meet the construction requirements of the NFIP and the communityrsquos floodplain ordinance and building code

This Recovery Advisory Addresses

Key NFIP requirements Communities in New Jersey and

Moving a buildingrsquos lowest floor to a higher elevation New York State enforce building codes that include requirements

NFIP requirements for enclosures below elevated buildings for buildings in flood hazard areas Special considerations for elevated buildings in Zone V Learn more about applicable codes

by checking with your local building Elevating mechanical electrical and plumbing systems to department

appropriate levels

Useful Links and Resources

Key NFIP Requirements Communities that participate in the NFIP are required to adopt and enforce local regulations that apply to new construction and buildings undergoing Substantial Improvement located in areas mapped as Special Flood Hazard Areas (SFHAs) The NFIP establishes minimum criteria and design requirements specifying how structures are to be constructed in order to minimize the potential for flood damage A primary requirement is that buildings must be elevated to or above the BFE Building owners can determine whether buildings are located within an SFHA by talking to a local floodplain administrator or building official and reviewing the Flood

Insurance Rate Map (FIRM) which shows the extent of the SFHAs and the BFEs For more information on NFIP

Terminology maps refer to the Hurricane Sandy Recovery Advisory Special Flood Hazard Area (SFHA) Land areas No 5 Designing for Flood Levels Above the BFE After subject to a 1 percent or greater chance of Hurricane Sandy (2013) flooding in any given year These areas are

Following large storm events such as Hurricane Sandy indicated on FIRMs as Zone AE A1-A30 A99

FEMA may publish Advisory Base Flood Elevation (ABFE) AR AO AH V VO VE or V1-30 Mapped zones

Maps to support recovery and improve future resiliency outside of the SFHA are Zone X B C or D

Communities must use ABFEs when designing recovery Base Flood Elevation (BFE) Elevation of or mitigation activities funded using FEMA grants flooding including wave height and runup (eg Public Assistance or Hazard Mitigation Grants) having a 1 percent chance of being equaled Recipients of the US Department of Housing and or exceeded in any given year (also known Urban Development (HUD) Community Development as ldquobase floodrdquo and ldquo100- year floodrdquo) BFEs Block Grants must use the ABFE plus 1 foot are the basis of insurance and floodplain

Before beginning any construction it is important management requirements and are shown on that building owners verify with their local building FIRMs department that they have all the State and local

Flood Insurance Rate Map (FIRM) A map permits required to do the project Mitigation projects produced by FEMA to show flood risk The such as those described in this advisory may result in SFHA and BFE are both shown on FIRMs the local building department making a determination FIRMs can be obtained at httpwwwmsc that the home is being Substantially Improved femagov Buildings determined by a building official or floodplain

of 17



ABFEs











buoyancy









buoyancy















Page 4 of 17




Terminology












Fill basement



$ Easy








Page 5 of 17
















Page 6 of 17









Page 7 of 17







Page 8 of 17












Page 9 of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17

Reducing Flood Risk and Flood Insurance Premiums for Existing Residential Buildings HSFE60-13-0002 0003 June 2013 of 17


ABFEs











buoyancy









buoyancy















Page 4 of 17




Terminology












Fill basement



$ Easy








Page 5 of 17
















Page 6 of 17









Page 7 of 17







Page 8 of 17












Page 9 of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17





buoyancy















of 17




Terminology












Fill basement



$ Easy








Page 5 of 17
















Page 6 of 17









Page 7 of 17







Page 8 of 17












Page 9 of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17




Terminology












Fill basement



$ Easy








of 17
















Page 6 of 17









Page 7 of 17







Page 8 of 17












Page 9 of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17
















of 17









Page 7 of 17







Page 8 of 17












Page 9 of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17









of 17







Page 8 of 17












Page 9 of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17







of 17












Page 9 of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17












of 17








Page 10 of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17








of 17















Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17

Reducing Flood Risk and Flood Insurance Premiums for Existing Residential Buildings HSFE60-13-0002 0003 June 2013 of 17














Page 12 of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17









of 17















Terminology





Page 13 of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17















Terminology





of 17




Flood Openings











Page 14 of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17




Flood Openings











of 17













Page 15 of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17













of 17



















Page 16 of 17
























Fax 240-699-0525




Page 17 of 17



















of 17
























Fax 240-699-0525




Page 17 of 17
























Fax 240-699-0525




of 17

Reducing Flood Risk and Flood Insurance Premiums for Existing

Documents

Transcript of Reducing Flood Risk and Flood Insurance Premiums for Existing