FEMA

Floodplain Management Bulletin 

Elevation Certificate

May 2004

FEMA 467-1
National Flood Insurance Program

Page 1 of 20 

Floodplain Management Bulletin 

Elevation Certificate 

This Floodplain Management Bulletin addresses frequently asked questions about the National 

Flood Insurance Program (NFIP) Elevation Certificate. The bulletin addresses the following 

questions: 

Introduction ........................................................................................................................................ 2 

Frequently Asked Questions: 

1) Are communities required to use the Elevation Certificate to verify compliance?.......................2 

2) Can the Elevation Certificate be used to determine the “as built” lowest floor of a 

structure?.......................................................................................................................................3 

3) What is the community’s responsibility for ensuring the Elevation Certificate is accurately 

 completed? ....................................................................................................................................6 

4) Is it important for the datum used for the elevations obtained in section C of the Elevation 

 Certificate to be the same as the datum used for the Base Flood Elevation in section B.9? ........7 

5) Why is it necessary to obtain the elevation of a crawlspace floor?...............................................8 

6) How can the elevation of a crawlspace floor be measured when the area is inaccessible?...........8 

7) How should the total area of permanent openings for section C3.i) be calculated if the 

 openings include some type of cover? ..........................................................................................9 

8) Why is elevation information needed for certain types of machinery and equipment in 

 section C3.e) of the Elevation Certificate? .................................................................................10

9) Why is it important for communities to ensure that all machinery and equipment 

 servicing the building is protected? ................................................................................................. 11 

10) What requirements apply to ductwork? .............................................................................................. 12 

11) Can the community use the Elevation Certificate to document compliance for all 

 machinery and equipment servicing the building? .....................................................................13 

12) Why does the Elevation Certificate request the elevation for “Highest Adjacent Grade” 

and “Lowest Adjacent Grade”? Why doesn’t the Elevation Certificate also request the 

 elevation for “Natural Grade”? ..................................................................................................14 

13) Is a survey required for Zone AO in order to complete the Elevation Certificate? ....................15 

14) Is it necessary to capture the elevation of a sunken room on the Elevation Certificate? ............16 

15) If the elevation of the slab foundation or other foundation was surveyed at the time it was 

 poured and no other changes have been made to the structure, is a final elevation 

 certification required after construction is completed? ..............................................................16 

16) Which diagram should be used for manufactured homes that have vinyl or aluminum 

 skirting?.......................................................................................................................................18 

17) Are Elevation Certificates required for accessory structures, such as a detached garage or 

 a storage shed? ............................................................................................................................18 

18) If an Elevation Certificate is prepared as part of a request for a Letter of Map Amendment 

 (LOMA) or Letter of Map Revision based on fill (LOMR-F), but a Base Flood Elevation 

 is not available in a Zone A, how can a Base Flood Elevation be obtained?..............................19 

Further Information, Comments, and Ordering Information .................................................................... 20 
National Flood Insurance Program Floodplain Management Bulletin 

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Introduction 

The Elevation Certificate (FEMA Form 81-31) is an important administrative tool of the NFIP. It is 

used to determine the proper flood insurance premium rate; it can be used to document elevation 

information necessary to ensure compliance with community floodplain management regulations; and it 

may be used to support a request for a Letter of Map Amendment (LOMA) or Letter of Map Revision 

based on fill (LOMR-F). This Floodplain Management Bulletin addresses frequently asked questions 

about completing and using the Elevation Certificate. 

This bulletin is primarily intended to assist local floodplain management officials with responsibility for 

administering the community’s floodplain management ordinance and to assist land surveyors, 

architects, and engineers who are authorized by law to certify elevation information on the Elevation 

Certificate. Insurance professionals who use the Elevation Certificate for insurance rating purposes may 

also find this bulletin useful. The information contained in this Floodplain Management Bulletin is not 

intended to replace the Instructions section of the Elevation Certificate, but to supplement them. 

Because a FEMA Elevation Certificate is needed before most flood insurance policies can be issued 

under the NFIP, communities are encouraged to obtain and maintain Elevation Certificates so that 

residents and businesses can easily obtain flood insurance. In order to participate in the NFIP 

Community Rating System (CRS), communities must require and maintain the Elevation Certificate for 

all new and substantially improved structures. 

References are made throughout this bulletin to various sections in the Elevation Certificate. You can 

obtain a copy of the Certificate through the Federal Emergency Management Agency (FEMA) 

Distribution Center or obtain a copy of the Certificate at the website 

http://training.nfipstat.com/ecsurveyor/. This is also the website for the Elevation Certificate tutorial. 

Frequently Asked Questions 

1) Are communities required to use the FEMA Elevation Certificate to verify 

compliance? 

The NFIP regulations do not mandate that a community participating in the NFIP use a specific form 

for keeping building elevation records. Under the NFIP, communities are required to obtain the 

elevation of the lowest floor (including basement) of all new and substantially improved structures and 

maintain a record of all such information [44 CFR 60.3(b)(5)]. The community’s permit files need an 

official record that documents to what height new buildings and substantial improvements in the 

Special Flood Hazard Area were elevated. This record is needed to show that buildings constructed in 

the floodplain are compliant with the community’s floodplain management ordinance. While 

communities can create their own forms for documenting elevation information, communities are 

encouraged to use the FEMA Elevation Certificate for documenting the elevation of various building 

elements (section C of the Elevation Certificate) and for documenting building compliance including 

the lowest floor determination (section G of the Elevation Certificate which is the Community 

Information section). The advantage of using the Elevation Certificate is that it will help the property 

owner in obtaining flood insurance since this form is used in determining a flood insurance rate. 

In order to participate in the CRS, communities are required to obtain and maintain completed FEMA 

Elevation Certificates for all buildings constructed or substantially improved in the Special Flood 

Hazard Area after the community’s initial date of application for the CRS. Credit is provided to CRS 

communities that maintain Certificates for all new and substantially improved buildings. A software 
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program has been developed to enter Elevation Certificate data into an electronic database using a 

personal computer. Additional credit is available to CRS communities that maintain Elevation 

Certificates in a computerized format and provide a disk of the Elevation Certificate data to FEMA 

each year. You can obtain the software by writing or emailing your request to: 

 The National Flood Insurance Program E-mail: NFIPCRS@ISO.COM

 Community Rating System (NFIP/CRS) 

 P.O. Box 501016 

 Indianapolis, IN 46250-1016 

2) Can the Elevation Certificate be used to determine the “as built” lowest floor 

of a structure? 

The local official can use the guidance in Figure 1 on the following pages to help determine which level, 

based on the elevation information provided in section C of the Elevation Certificate, is the lowest floor. 

However, the local official should not rely solely on the Elevation Certificate for determining the lowest 

floor without inspecting the building site and without discussions with the permit applicant. Although 

section C of the Elevation Certificate records the elevation of the various building floors and 

components, this section does not specifically identify the “as built” lowest floor of the building or 

indicate whether the building, as constructed, complies with the community’s floodplain management 

regulations. The determination of the “as built” lowest floor for compliance with the community’s 

floodplain management ordinance is the responsibility of the local floodplain management official. The 

most effective way to ensure compliance is to inspect the site frequently during construction. This is 

particularly important in the early phases of work on a building because that is when errors in the 

elevation of the lowest floor can be found and most easily corrected. 

The “Diagram Description” in the left hand column below refers to the eight Diagrams included in the 

Instructions for the Elevation Certificate. The “As Built Lowest Floor Determination” in the right hand 

column refers to the location that should be the lowest floor based on the type of building for which an 

“as built” determination is being made. The local official can document the “as built” lowest floor in 

item G8. of the Elevation Certificate (section G) or can document the “as built” elevation information 

on other community permit forms. Communities should also conduct the appropriate inspections to 

verify the elevation information and other information on the Elevation Certificate and to determine the 

building’s lowest floor to ensure that the building complies with the community’s floodplain 

management regulations (See Question 15). 
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Figure 1. “As Built” Lowest Floor Guide 

Diagram Description: “As Built” Lowest Floor Determination

Diagram 1: Slab-on-grade buildings. A Zones: C3.a, top of bottom floor. 

 V Zones: See Note 1. 

Diagram 2: Buildings with basements. A Zones: C3.a, top of bottom floor (including 

 basement). 

 V Zones: See Note 1. 

Diagram 3: Split-level slab-on-grade A Zones: C3.a, top of bottom floor. 

buildings. V Zones: See Note 1. 

Diagram 4: Split-level buildings other A Zones: C3.a, top of bottom floor (including 

than slab-on-grade. basement). 

 V Zones: See Note 1. 

Diagram 5: Buildings elevated on piers A Zones: C3.a, top of elevated floor. 

posts, piles, columns, or parallel shear V Zones: C3.c, bottom of lowest horizontal 

walls (no obstructions, but open lattice structural member. 

and/or screening is permissible.) 

Diagram 6: Buildings elevated on piers, A Zones: If the enclosure has proper openings 

posts, piles, columns, or parallel shear AND is used solely for parking, 

 walls with full or partial enclosure. building access, or storage (see Note 

2): C3.b, top of elevated floor. 

If the enclosure does NOT have proper 

openings OR is used for something other 

than parking, access, or storage: C3.a, 

top of floor of enclosure. 

 V Zones: If the enclosure’s walls are break 

away AND the enclosure is used 

solely for parking, building access, or 

storage (see Note 3): C3.c, bottom of 

lowest horizontal structural member 

of the elevated floor. 

If the enclosure’s walls are NOT 

breakaway OR the enclosure is used 

for something other than parking, access or storage: C3.a, floor of enclosure. 

Continued on next page
National Flood Insurance Program Floodplain Management Bulletin 

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Figure 1. “As Built” Lowest Floor Guide 

 

Diagram Description: “As Built” Lowest Floor Determination

Diagram 7: Buildings elevated on A Zones: If the walkout level (enclosure) has 

full-story foundation walls with partial the proper openings AND is used 

or full enclosure. solely for parking, building access, or 

 storage (see Note 2): C3.b, top of 

 next higher floor. 

 If the walkout level (enclosure) does 

 NOT have the proper openings OR 

is used for something other than parking, 

access, or storage: C3.a, top of floor of 

walkout level. 

 V Zones: See Note 1. 

Diagram 8: Buildings elevated on A Zones: If the crawlspace enclosure has the 

crawlspace. (See Note 4 on proper openings (see Note 2): C3.b, top 

differentiating between a of next higher floor. 

crawlspace and a basement.) If the crawl space enclosure does 

 NOT have the proper openings: 

 C3.a, top of floor of crawlspace. 

 V Zones: See Note 1. 

Attached Garage (when garage floor is If the garage has the proper openings (see 

below the Base Flood Elevation): Note 2), then the garage floor (C3.d) is not the 

“lowest floor” for purposes of determining the asbuilt lowest floor of the building in item G8.of the 

Elevation Certificate. 

 If the building has an attached garage that 

 does NOT have the proper openings, then the

 garage floor (C3.d) is the “lowest floor” that 

 should be identified in G8.

Equipment: Under the NFIP, buildings Even though the building may be properly elevated

must be constructed with electrical, based on the “as built” lowest floor, it is not a 

heating, ventilation, plumbing, and air- compliant building unless the equipment is 

conditioning equipment and other properly elevated or floodproofed. 

service facilities that are designed and/or See also Protecting Building Utilities From Flood 

located so as to prevent water from Damage, FEMA 348, 2000. 

entering or accumulating within the 

components during conditions of flooding. 

Generally, this is done by elevating 

equipment above the Base Flood Elevation, 

but there are ways to floodproof equipment 

to keep water out. 

Continued on next page
National Flood Insurance Program Floodplain Management Bulletin 

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3) What is the community’s responsibility for ensuring the Elevation 

Certificate is accurately completed? 

If the community maintains Elevation Certificates on file, it is the community’s responsibility to 

ensure that the Certificate is completed correctly. Communities should do this as a general practice 

for any elevation certifications even if elevations are provided on the community’s own forms or 

plans. The community should proofread the Elevation Certificate provided by surveyors for any 

errors or omissions, such as a wrong Flood Insurance Rate Map Index or Panel date or diagram 

number or for missing information in section C. If there are Certificates that have some of the items 

omitted or incorrectly filled out, the community has the following options. 

1) For any inaccurate or incomplete information in items C3.a)-d), f), or g), the local official 

should request a new Elevation Certificate. If the local official uses elevation information taken 

Figure 1. “As Built” Lowest Floor Guide 

Note 1. V Zone buildings that are constructed similar to Diagrams 1-4, 7 and 8, are violations 

under the NFIP. For buildings in V Zones the lowest floor is measured at the bottom of the 

lowest horizontal structural member, which will be the bottom of the slab or a footing. 

Note 2. Enclosures and Openings in A Zones (Diagrams 6, 7, and 8). The NFIP Floodplain 

Management Regulations permit limited uses of enclosures below the lowest floor. The 

enclosed area below an elevated building cannot be used for other than parking of vehicles, 

building access, or storage. The enclosure must be built with flood resistant materials. The 

enclosed areas below an elevated building must contain openings. An opening is defined as: A 

permanent opening in a wall that allows for the free passage of water automatically in both 

directions without human intervention. Openings are explained on the last page of the Elevation Certificate Instructions and in Technical Bulletin 1-93 on Openings in Foundation Walls 

for Buildings Located in Special Flood Hazard Areas (FIA-TB-1). The number and total area 

of openings are provided in C3.h and i. The floor area measurement should be on the permit 

plans. 

Note 3. In V Zones, an enclosure (as shown in Diagram 6) must be constructed with nonsupporting, non-load bearing breakaway walls, which meet applicable NFIP criteria. The enclosure can only be used for parking of vehicles, building access and storage. The enclosure must be 

built with flood resistant materials. Flood insurance rates increase significantly when the area of 

the enclosure is 300 square feet or more. 

Note 4. Crawlspace Construction (Diagram 8): If the floor of the crawlspace is below the Base 

Flood Elevation, NFIP requirements can be met by ensuring that the interior floor of the crawlspace is at or above the lowest adjacent grade to the building and the crawlspace contains 

openings. If the floor of the crawlspace is below the Base Flood Elevation and the interior floor 

of the crawlspace is below the adjacent exterior grade on all sides of the building, Diagram 2 or 4 

must be used. Additional guidance on crawlspace construction can be found in Technical Bulletin 11-01, Crawlspace Construction for Buildings Located in Special Flood Hazard Areas, (FIATB-11). 
National Flood Insurance Program Floodplain Management Bulletin 

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from other documentation that has been signed and embossed by a licensed surveyor, engineer, 

or architect who is authorized by state or local law to certify elevation information to complete 

section C, the local official needs to ensure the certified elevations are accurate and complete 

before entering them in section C. If not, the local official should request new certified 

elevations. Note: If the community uses elevation information taken from documentation other 

than the FEMA Elevation Certificate, the local official should check the box in G1. on the 

Elevation Certificate and indicate in the comment section the source of the elevation data. 

2) The local official can do the following if incomplete or inaccurate information is found in 

sections A, B, or C1, C2, and C3.e), h) and i). Note: The local official should not mark up 

the form with the correct information because the information in sections A, B and C is 

certified by a land surveyor, engineer, or architect who is authorized by law to certify 

elevation information. 

a) The forms may be returned to the surveyor with instructions on what needs to be changed 

or corrected; 

b) The local official can prepare a separate memo with the correct information and attach the 

memo to the form. When the Certificate is provided to an inquirer, the memo must be 

included with it; or 

c) The local official can note the changes or corrections in section G of the Elevation 

Certificate under Comments. 

3) If the community uses Elevation Certificate software or maintains the elevation information in 

a database, the community can correct sections A and B, and subsection C1, C2, and C3.e), h), 

and i) when the data from the Certificate is entered into the Elevation Certificate software or 

database. It must be noted in section G what changes were made to the original paper copy. 

The local official should check item G1 when data are entered into database or elevation 

certificate software. The community will still need to keep the original Certificate, but can 

hand out copies printed from the corrected electronic version. 

It should be noted that the community assumes responsibility for the accuracy of the changes it 

makes. Therefore, data entry for electronic versions should be double-checked. 

One way communities can ensure that Elevation Certificates are accurately filled out is to complete 

sections A and B at the time of the permit application. The partially completed form can then be 

given to the surveyor who can then focus on completing the surveyed information in section C. If a 

community does complete section A and B, the surveyor should note in the comment section that 

the surveyor’s certification is limited to section C. 

4) Is it important for the datum used for the elevations obtained in section C 

of the Elevation Certificate to be the same as the datum used for the Base 

Flood Elevation in section B.9? 

Yes. If the datum for the elevations in items C3.a)-g) are not properly converted when necessary, it 

could result in an inaccurate determination of compliance by the local floodplain management 

official or it could result in an inaccurate flood insurance rate. In item B1. of the Elevation 

Certificate, the elevation datum (either NGVD 1929 or NAVD 1988) to which the Base Flood 

Elevations on the applicable FIRM are referenced should be indicated. All elevations in section C 

must be referenced to the datum on which the Base Flood Elevation is based. If a datum conversion 
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is necessary, show the field measurements and datum conversion calculation in section C or in the 

Comments of section D or G, as appropriate. 

5) Why is it necessary to obtain the elevation of a crawlspace floor? 

It is very important that the elevation of the crawlspace floor be obtained so that, in the case of new 

or substantially improved construction, the community can determine compliance of the building 

with the community’s floodplain management ordinance and the insurance agent can properly rate 

the structure for flood insurance. 

If the floor of the crawlspace is below grade on all sides or the crawlspace foundation walls do not have 

proper openings in accordance with 44 CFR 60.3(c)(5) of the NFIP regulations that allow for the 

automatic entry and exit of floodwaters into the crawlspace area there is an increased risk of flood 

damages to the building due to hydrostatic pressure. The crawlspace foundation could be damaged or 

fail completely. It doesn’t matter whether the crawlspace floor is a dirt floor or a finished floor. 

The flood insurance rates for structures with crawlspaces up to 2 feet below-grade on all sides are higher 

than those for buildings that have the interior grade of the crawlspace at or above the lowest adjacent 

grade, since the risk of flood damage is greater for this type of construction. For structures that have 

their crawlspace floors greater than 2 feet below-grade, a full basement rate will be charged. These rates 

are higher still due to the increased risk of flood damage to the building. 

Additional guidance on crawlspace construction can be found in Technical Bulletin 11-01, Crawlspace 

Construction for Buildings Located in Special Flood Hazard Areas, (FIA-TB-11). 

6) How can the elevation of a crawlspace floor be measured when the area is 

inaccessible? 

It is recognized that surveyors may not have access to some crawlspaces in buildings due to height 

restrictions or lack of an access door and may not be able to shoot an elevation of the interior floor of 

the crawlspace. 

If the surveyor has limited access to the crawlspace, such as in the case of the building in Figure 2, and 

is unable to shoot an elevation of the floor of the crawlspace [C3.a)], the surveyor can do the following: 

a. Use a yardstick or tape measure to check the floor height to the next highest floor, and then subtract 

the crawlspace height from the elevation of the “next higher floor” [C3.b)]. Provide the elevation in 

the comment section only and provide a brief description of how the elevation was obtained. 

b. Contact the local floodplain administrator for the community that the building is located in. The 

community may have documentation of the elevation of the crawlspace floor as a part of the permit 

process for the building. Provide the elevation in the comment section and provide a brief 

description of how the elevation was obtained. 

c. If the property owner has documentation or knows the height of the crawlspace floor to the next 

higher floor, try to verify this by looking inside the crawlspace through any openings or vents. If 

information appears to be reliable, provide the elevation in the comment section and provide a brief 

description of how the elevation was obtained.
National Flood Insurance Program Floodplain Management Bulletin 

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NOTE: For all three suggestions above, under subsection C3.a) Top of bottom floor (including 

basement or enclosure) of the Elevation Certificate, the surveyor should indicate the following: “See 

comments section.” 

7) How should the total area of permanent openings for section C3.i) be 

calculated if the openings include some type of cover? 

Buildings constructed on extended foundation walls or that have other enclosures below the Base 

Flood Elevation in A Zones are subject to flood forces that include hydrostatic pressure of 

floodwaters against the foundation or enclosure walls. If the walls are not designed to withstand 

hydrostatic pressure, they can be weakened or can fail causing damages to the building. The NFIP 

Regulations at 44 CFR 60.3(c)(5) require that foundation and enclosure walls of buildings 

constructed in A Zones contain openings (flood vents) that will permit the automatic entry and exit 

of floodwaters. These openings allow floodwaters to reach equal levels on both sides of the walls 

and thereby lessen the potential for damage from hydrostatic pressure. Under the NFIP, the 

following requirements must be met for all new or substantially improved A Zone buildings that 

have enclosed areas below the Base Flood Elevation: 

• There must be a minimum of two openings and the openings should be on different sides of 

each enclosed area. If a building has more than one enclosed area, each area must have 

openings on exterior walls to allow floodwater to directly enter. 

• The total net area of all openings must be at least 1 square inch for each 1 square foot of 

enclosed area. 

• The bottom of each opening can be no more than 1 foot above the adjacent grade. 

In situations where it is not feasible or desirable to meet the openings criteria stated above, a design 

professional (registered architect or engineer) may design and certify the openings. See Technical 

Bulletin 1-93 on Openings in Foundation Walls for Buildings Located in Special Flood Hazard 

Areas (FIA-TB-1) for additional guidance on the openings requirement. In all cases, any grates, 

louvers, grills, bars, or other opening covers must not block or impede the automatic flow of 

floodwaters into and out of the enclosed area. 

Figure 2. Limited Access to Crawl Space Letters equate to items 

in Section C3. of the 

Elevation Certificate: 

a) Top of bottom floor 

b) Top of next higher 

floor 

f) Lowest adjacent 

grade 

g) Highest adjacent 

grade 

h) No. of permanent 

openings 

i) Total area of all 

permanent openings 

in square inches. 
National Flood Insurance Program Floodplain Management Bulletin 

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Item C3.h) of the Elevation Certificate asks for the number of permanent openings in the walls 

supporting the building that are no higher than 1 foot above the adjacent grade and item C3.i) asks 

for the total area of all such openings in square inches. If there are no permanent openings within 1 

foot above the adjacent grade, “0” (zero) should be entered in items C3.h) and i). Also, the surveyor 

should note in the Comments section whether the openings are in the foundation walls of the 

building and/or in the walls of any attached garage. 

When there are grates, louvers, grills, or other opening covers as indicated in Figure 3, the surveyor 

can estimate the net open area in the flood vent (total area of all permanent openings in square 

inches). If the size of the openings, excluding any grates, louvers, grills, or other covers, cannot be 

estimated, the surveyor can measure the size of the opening, without consideration to the existence 

of any covers, and indicate in the comment section the type of opening cover that exists. It is the 

community’s responsibility and not the surveyor’s to determine whether the size, number, and 

location of the openings meet the requirements of the community’s floodplain management 

ordinance. 

8) Why is elevation information needed for certain types of machinery and 

equipment in section C3.e) of the Elevation Certificate? 

Because the area below the lowest elevated floor of an elevated building is exposed to floodwaters, 

there is limited flood insurance coverage in this area for Post-FIRM (Flood Insurance Rate Map) 

buildings located in zones A1-A30, AE, AH, AR, AR/A, AR/AE, AR/AH, AR/A1-A30, V1-V30, or 

VE. Flood insurance is provided for foundation elements that support the building, access stairs, and 

certain machinery and equipment items that are considered essential building elements located in 

enclosed areas below the lowest elevated floor of elevated buildings. The machinery and equipment 

items include a furnace, water heater, heat pump, air conditioner, and elevator. No coverage is provided 

for enclosures and only limited coverage is available for personal property contained therein. 

For flood insurance purposes, the underwriter needs to know the lowest elevation of at least one

covered machinery and equipment item in order to determine if a rate loading or surcharge is necessary. 

Figure 3. Examples of Opening Covers 

 

Grate Louver Grill
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Thus, the Elevation Certificate requires that the surveyor provide the elevation of the one machinery 

and equipment item if it is a furnace, hot water heater, heat pump, air conditioner, or elevator in C3.e) 

that has the lowest elevation and indicate the type of machinery and equipment surveyed in section D. 

An insurance rate loading is determined based on the elevation of the machinery and equipment item 

that is below the Base Flood Elevation. Additional information about other machinery and equipment is 

obtained on Part II of the Flood Insurance Application. 

Note that the lowest elevation of machinery and equipment is needed whether the machinery and 

equipment is located inside or outside of the footprint of the building. For example, if the slab for 

an air conditioning condenser unit is the lowest elevation of covered machinery, then that is the 

elevation that should be documented in C3.e). However, the local floodplain management official is 

required to ensure that all machinery and equipment servicing the building are protected from flooding 

(See Questions 9 and 10). While the Elevation Certificate requires the elevation of only one machinery 

and equipment item, Question 11 addresses how community officials can ensure that all machinery and 

equipment is protected in accordance with the community’s floodplain management ordinance and how 

compliance of these items can be documented. 

9) Why is it important for communities to ensure that all machinery and 

equipment servicing the building is protected? 

Protecting a building from flood damage means more than elevating the lowest floor to or above the 

Base Flood Elevation. Sections 60.3a(3)(ii) and (iv) of the NFIP regulations require that buildings “(ii) 

be constructed with materials resistant to flood damage” and “(iv) be constructed with electrical, 

heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are 

designed and/or located so as to prevent water from entering or accumulating within the components 

during conditions of flooding.”

Flood insurance claims as well as post-disaster assessments have shown that significant damage to the 

machinery and equipment servicing the building (e.g., furnaces, hot water heaters, air conditioners, fuel 

systems, electrical receptacles, ductwork, and insulation) can occur due to improper design and location 

of these systems below the Base Flood Elevation. Floodwater often contains dissolved chemicals, silt, 

suspended solids, and floating debris. Moving floodwater exerts pressure on everything in its path, and 

causes erosion of soil and scour around solid objects. 

With such destructive characteristics, floodwaters present many hazards to the often-fragile components 

of building support utility systems including corrosion, contamination, flotation, dislocation, and other 

physical damages. Improperly designed or located machinery and equipment below the Base Flood 

Elevation that become dislodged can also increase damages to the structure itself even though the 

building’s lowest floor was high enough. In addition, mold, mildew and fungus accumulating in flood 

damaged air passageways, such as ductwork, often can lead to serious health issues for residents or 

occupants of the structure. As a result, improperly designed and located machinery and equipment can 

result in increased costs and potentially extensive repairs. If the machinery and equipment servicing the 

building is damaged or destroyed, the building may be unusable for days or even longer. 
National Flood Insurance Program Floodplain Management Bulletin 

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In A Zones, utilities and equipment must be either elevated to or above the Base Flood Elevation or 

made watertight to the Base Flood Elevation so that the components are protected from flood damages. 

In V Zones, utilities and equipment must be elevated to or above the Base Flood Elevation. If not, then 

the building is not in compliance with the NFIP floodplain management regulations. 

10) What requirements apply to ductwork? 

One question that gets frequently raised is related to the requirements that apply to ductwork. Ductwork 

must be either elevated above the Base Flood Elevation or if ductwork is located below the Base Flood 

Elevation, it must be made watertight to prevent water from entering or accumulating within the system 

components when inundated by floodwaters. 

Equipment and the supporting distribution system should be elevated such as in Figure 4 or, as an 

alternative, property owners and builders should consider locating ductwork in the attic as indicated in 

Figure 5. 

 

Ductwork may only be located below the Base Flood Elevation in new or substantially improved 

structures in a Special Flood Hazard Area as shown in Figure 6 if it is made watertight. This technique 

(making ductwork watertight) is only allowed in A Zones. Although it is possible to design and 

construct ductwork so that it is watertight to keep floodwater from entering the system components, this 

technique is not commonly used. In V Zones, ductwork must be elevated to or above the Base Flood 

Elevation. 

Ductwork that is not elevated to or above the Base Flood Elevation or is not made sufficiently 

watertight to keep floodwater from entering the system components is considered non-compliant as 

shown in Figure 6. 

Figure 5. Compliant machinery and 

equipment. 

Figure 4. Compliant machinery and 

equipment. 
National Flood Insurance Program Floodplain Management Bulletin 

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11) Can the community use the Elevation Certificate to document 

compliance for all machinery and equipment servicing the building? 

The community can use the Elevation Certificate to document compliance of all utilities, ductwork, 

machinery, and equipment or the community can use its own forms to document compliance. The 

following steps are recommended to communities to ensure that all machinery and equipment are in full 

compliance with the NFIP. 

• Review your community’s floodplain management ordinance and verify that it clearly requires 

elevation and protection of utilities, ductwork, machinery, and equipment to or above the Base 

Flood Elevation. If not, the floodplain management ordinance should be revised to include these 

requirements. If in doubt, ask your community’s legal counsel whether the ordinance can be 

interpreted as providing this protection or check with the FEMA Regional Office or the State 

Coordinator for the NFIP. 

• Review your permit application and inspection procedures to determine the best way to ensure that 

the requirement is being met. This may necessitate procedural changes such as additional 

information on the permit application form, additional plans provided by the permit applicant, an 

addition to a field inspection checklist, and/or a photograph for the record at the time of the final 

inspection. 

• Discuss the matter with local builders and architects as necessary. Refer them to FEMA’s manual, 

Protecting Building Utilities from Flood Damage, FEMA 348. 

• Make sure the building plans clearly indicate that the building’s utilities, ductwork, machinery, and 

equipment, such as furnaces, water heaters, heat pumps, air conditioners, and elevators and their 

associated equipment, will be properly elevated or that the components located below the Base 

Flood Elevation will be protected such that floodwater is prevented from entering or accumulating 

within the system components (watertight) (allowed in A zones only) before issuing the permit. 

• Inspect the location of all utilities, ductwork, machinery, and equipment during the course of 

construction and make a final inspection after construction is completed to ensure that these items 

comply with the community’s floodplain management regulations. 

Figure 6. Non-compliant ductwork For additional guidance on protecting utilities 

and other equipment servicing the building 

from flood damage, see FEMA manual, 

Protecting Building Utilities from Flood 

Damage, FEMA 348. This document reviews 

principles and practices for the design and 

construction of flood resistant building utility 

systems including ductwork and other 

equipment from flood damage. 
National Flood Insurance Program Floodplain Management Bulletin 

Page 14 of 20 

• Make sure that the community records show that utilities, ductwork, machinery, and equipment 

have been properly elevated or made watertight (A zones only) once construction has been 

completed. Elevation of these items can be documented in the following ways: 

o The community can document elevation of utilities, ductwork, machinery, and 

equipment on the community inspection records. The final inspection records can note 

that the bottom of the items, such as ductwork, are “X” feet above or below the lowest 

floor or the actual elevation can be used; 

o The community can document compliance of utilities, ductwork, machinery, and 

equipment in the Comments area of section G of the Elevation Certificate. The 

community can note in section G that the bottom of these items, such as ductwork, is 

“X” feet above or below the lowest floor or the actual elevation of these items can be 

used; or 

o The Elevation Certificate for finished construction requires the surveyor to enter the 

lowest elevation of one machinery or equipment item – a furnace, water heater, heat 

pump, air conditioner, or elevator – located in an attached garage or enclosure or on an 

open utility platform that provides utility services for the building in C3.e). If there is 

more than one machinery and/or equipment item, the community can require the 

surveyor to document the elevation of all machinery and equipment and list the type of 

machinery and equipment in the Comments area of section D when the Elevation 

Certificate is being used to document compliance. However, the community must still 

verify through inspections that all machinery and equipment comply with the 

community’s floodplain management regulations. 

NOTE: Ductwork is not included in machinery and equipment that the surveyor must 

capture in C3.e) of the Elevation Certificate. However, the community can ask the 

surveyor to document the elevation of the bottom of the ductwork in section D of the 

Elevation Certificate or a community can document the elevation of ductwork in the 

community’s inspection records or in section G of the Elevation Certificate. 

Where component protection is used for utilities, ductwork, and other machinery and equipment, 

the community should require documentation on the plans and indicate in the inspection records 

that these items have been designed and constructed so as to prevent floodwaters from entering or 

accumulating within the components during conditions of flooding (watertight). 

12) Why does the Elevation Certificate request the elevation for “Highest 

 Adjacent Grade” and “Lowest Adjacent Grade”? Why doesn’t the 

Elevation Certificate also request the elevation for “Natural Grade”? 

Both the highest adjacent grade and the lowest adjacent grade are included in section C3. because it 

provides a clearer picture of how the building is constructed relative to the terrain. It also helps to verify 

that the diagram number chosen for the building is most similar to the building surveyed. This is 

particularly important for insurance rating since the underwriter at the insurance company will likely 

never see the building. 

In Zones A1-30, AE, AH, AO, A (with a Base Flood Elevation), VE, V1-30, V (with a Base Flood 

Elevation) AR, AR/A, AR/AE, AR/A1-30, AR/AH, and AR/AO, natural grade information should be 

obtained by the community as part of the floodplain development permit application. The natural grade 

information should be obtained at this stage before any permit is issued in order to determine the 
National Flood Insurance Program Floodplain Management Bulletin 

Page 15 of 20 

relationship between the natural ground and the Base Flood Elevation. This information is necessary in 

order to determine how high the building ultimately needs to be elevated. This information can be 

obtained from topographic information or from spot elevations obtained as part of site plans or drainage 

plans. 

The community should document the natural grade information on the permit application or in section 

G of the Elevation Certificate. If the Elevation Certificate is used as part of the permit application and 

the building elevation is based on construction drawings, then the “Construction Drawings” box should 

be checked under item C1. of the Elevation Certificate. 

13) Is a survey required for Zone AO in order to complete the Elevation 

Certificate? 

No. Section C, which must be completed and certified by a surveyor, is not required for Zone AO. 

Only sections E and F are required to be completed. The information in section E is all that is 

needed in order to rate the structure for insurance purposes provided that sections A and B are also 

completed. However, if the elevations are intended for use in supporting a LOMA or LOMR-F, 

section C must be completed with certified elevations. 

Although a survey is not required for Zone AO to complete the Elevation Certificate, the local 

floodplain management official must take appropriate actions to ensure that the structure is built in 

compliance. In Zone AO, all new and substantially improved buildings must have the lowest floor 

(including basement) above the highest adjacent grade at least as high as the depth number 

specified in feet on the community’s FIRM (at least two feet if no depth number is specified) [44 

CFR 60.3(c)(7)]. Under the NFIP, highest adjacent grade means “the highest natural elevation of 

the ground surface prior to construction next to the proposed walls of a structure.” (44 CFR 

59.1). 

In order to ensure that a building in Zone AO is properly elevated, the community will have to 

determine that the lowest floor (including basement) is above the highest adjacent grade at least as 

high as the AO Zone depth. This may include reviewing grading plans and looking at topographic 

information before the building is constructed, and conducting inspections during the course of 

construction and before the building is occupied. 

As part of the administration of the community’s subdivision ordinance, a community may already 

be requiring grading plans and other site information in which the elevation of the ground is 

provided as part of the subdivision review. The local floodplain management official should check 

the ground elevation information as part of the permit process in an AO Zone so that it can be used 

later to determine whether the lowest floor is above the highest adjacent grade at least as high as the 

AO Zone depth. The community should document the ground elevation information in the 

floodplain development permit file or in section G of the Elevation Certificate. 

If the community does not require a site plan or grading plan, the community could require a 

survey of the ground elevation, check topographical information, if it is available and is sufficiently 

detailed, or require the builder to place a reference mark on the site so that the local official can 

determine that the building is elevated on fill to or above the required number of feet above natural 

grade. 

Communities shall not base their lowest floor determination on the completion of section E by the 

property owner or his or her agent. Under the NFIP, it is the community’s responsibility to ensure 

that the building is built according to the permit application. The local floodplain management 
National Flood Insurance Program Floodplain Management Bulletin 

Page 16 of 20 

official should conduct a sufficient number of inspections to ensure that the building is built in 

compliance. 

14) Is it necessary to capture the elevation of a sunken room on the 

Elevation Certificate? 

Yes. The elevation of a sunken room or a sunken area within a room should be captured on the 

Elevation Certificate in item C3. of the Elevation Certificate at either C3.a) “Top of the bottom 

floor” or C3.b) “Top of next higher floor” depending on its location above or below other floors 

such as a basement. The floor of the sunken room could be considered the “lowest floor” under the 

community’s floodplain management ordinance depending on its location relative to other floors. 

The sunken room could also be considered the “lowest floor” for insurance rating purposes. 

If the sunken room is below grade on all four sides as illustrated in Figure 7, it is considered a 

basement and Diagram 2 should be selected for item C2. of the Elevation Certificate. 

15) If the elevation of the slab foundation or other foundation was surveyed 

at the time it was poured and no other changes have been made to the 

structure, is a final elevation certification required after construction is 

completed? 

Yes. Once construction of the building is completed, the community must obtain "as built" 

elevation information on the building to determine whether the building is compliant in accordance 

with 44 CFR 60.3(b)(5)(i). As indicated in question 1, there is no mandated form – the community 

can use its own form or the Elevation Certificate to document the “as built” elevation information. 

These elevations need to be surveyed by a surveyor, engineer, or architect who is authorized by law 

to certify such elevation information. Use of a tape measure is not sufficient for determining “as 

built” elevation information and cannot be used for completing section C of the Elevation 

Certificate for the various floor elevations of the building required on the Certificate. 

The “as built” elevation information must be obtained before an occupancy permit is issued. While 

construction is underway and changes can be more easily made to bring the building into 

compliance, the community should still verify that the building is elevated to the proper elevation 

and that other building elements will be protected from flood damages. Community floodplain 

management officials should not assume that construction and development will proceed as spelled 

out in the approved permit. The most effective way to ensure compliance is to inspect the building 

Figure 7. Building with a Sunken Room 

Letters equate to items in 

Section C3. of the 

Elevation Certificate: 

a) Top of bottom floor 

(include basement or 

enclosure) 

b) Top of next higher floor

f) Lowest adjacent grade 

g) Highest adjacent grade
National Flood Insurance Program Floodplain Management Bulletin 

Page 17 of 20 

site frequently during construction. A series of at least three inspections is recommended for any 

project that involves construction of a building in the floodplain. 

The first inspection should be done before the ground is broken to determine that the site as 

identified on the permit application and proposed plans are consistent with actual ground 

conditions. This provides the local official an opportunity to check the floodplain/floodway 

boundaries, any setback lines, channel banks, etc. 

A second inspection is recommended just before installation of the lowest floor to ensure that this 

floor will be built at the elevation stipulated in the permit application, and the foundation is the type 

specified in the plans. The type of foundation may dictate the schedule for this inspection. For 

example, if the building has a slab foundation, the inspection is best done when the forms are 

placed. If the forms for the slab are high enough, the local official can approve pouring the slab. In 

another example, if the building has an elevated foundation, (e.g., crawlspace), the inspection is 

best done when the foundation is completed. If the top of the foundation of the crawlspace is high 

enough, the local official can approve placement of the floor. 

Making sure the lowest floor is properly elevated is the key to the entire floodplain construction 

process. The floor elevation can be checked during the second inspection in a couple of ways. The 

local official can require the builder to obtain a certification of the floor elevation or alternatively, 

the local official can use a hand level to determine whether the lowest floor will be as high as the 

reference mark established by the builder’s surveyor before construction began. This reference 

mark could be located on a nearby stationary object such as a telephone or light pole or the 

surveyor could establish the reference mark on a stake. Use of a hand level will give the local 

official a rough estimate that the building will be constructed to the correct elevation. However, it is 

not as accurate an elevation as a survey. 

During the second and later inspections the local official should also begin checking other building 

elements against the permit and the plans, such as whether the fill meets necessary compaction, 

slope, and protection requirements; the location of utilities are being properly protected; and if any 

openings are required, they are of the appropriate number and size and are located at the 

appropriate height above grade. 

The local official should conduct a final inspection and obtain the “as-built” elevation certification 

to determine if the lowest floor is at the proper elevation. This inspection should be done as the 

project nears completion and before the certificate of occupancy or certificate of compliance is 

issued. The “as built” certification can be documented on the Elevation Certificate or on the 

community’s own forms or on the plans. During this final inspection, all building elements (such as 

enclosures, openings, utilities, ductwork, machinery and equipment, breakaway walls, and 

anchoring) need to be thoroughly inspected to ensure that they comply with the community’s 

floodplain management regulations. 

For insurance purposes, for a building under construction, the survey should include only the 

elevations surveyed in items C3.a)-g). The remaining elevations, if applicable, should be obtained 

from the construction plans or drawings and entered as Comments in section D. Buildings in the 

course of construction are rated the same as completed construction. A renewal application and a 

new Elevation Certificate are required at renewal time once the building has been completed. The 

new Elevation Certificate should then be based on “Finished Construction” in item C1. 
National Flood Insurance Program Floodplain Management Bulletin 

Page 18 of 20 

16) Which diagram should be used for manufactured homes that have vinyl 

or aluminum skirting? 

If the vinyl or aluminum skirting is purely for decorative purposes, the skirting can be disregarded 

and Diagram 5 can be used in both A and V Zones. However, if the area below the manufactured 

home’s lowest floor is enclosed by something other than vinyl or aluminum skirting, it may be an 

enclosure in which case Diagrams 6 or 8 may be more appropriate. The surveyor can note in the 

Comments section whether the manufactured home includes vinyl or aluminum skirting. Openings 

are not required if vinyl or aluminum skirting is used. 

The local official should document on the permit whether skirting will be used or whether the area 

below the manufactured home’s lowest floor will be an enclosure before issuing a permit. If an 

enclosure is created below the manufactured home’s lowest floor, the enclosure can only be used 

for parking, access, or storage. If the manufactured home is located in an A Zone, the enclosed area 

must include openings [44 CFR 60.3(c)(5)]. If it is located in a V Zone, the area below the lowest 

horizontal structural member of the lowest floor must be either free of obstruction or constructed 

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

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

damage to the elevated portion of the manufactured home or supporting foundation system [44 

CFR 60.3(e)(5)]. 

17) Are Elevation Certificates required for accessory structures, such as a 

detached garage or a storage shed? 

If a community requires that an accessory structure must be elevated to or above a specified 

elevation, then an Elevation Certificate or similar documentation will be needed to ensure that the 

accessory structure was built in compliance. Communities may allow accessory structures that are 

not elevated or dry floodproofed (made watertight) provided that they represent a minimal 

investment and are designed to have a low damage potential with respect to the structure and 

contents. These structures could include a two-car detached garage or smaller or a small shed. 

Generally, a community should allow wet floodproofed accessory structures only through its 

variance process unless it has established specific criteria in its floodplain management regulations. 

If the community allows wet floodproofed accessory structures, a certification of the elevation of 

the lowest floor to which the accessory structure is built is not required. 

The Dwelling Form of the Standard Flood Insurance Policy written to cover a 1-4 family residence 

also covers a detached garage on the lot, but the coverage is limited to no more than 10 percent of 

the limit of the liability on the dwelling. Use of this insurance coverage is at the policyholder’s 

option but reduces the building limit of liability on the main building. In this case, an Elevation 

Certificate is not required for the detached garage to be covered under the Dwelling Form. 

If the property owner chooses to separately insure the detached garage under the Standard Flood 

Insurance Policy, then an Elevation Certificate will be required. Also, an Elevation Certificate is 

required if the property owner chooses to individually insure other accessory structures under the 

Standard Flood Insurance Policy. 
National Flood Insurance Program Floodplain Management Bulletin 

Page 19 of 20 

18) If an Elevation Certificate is prepared as part of a request for a Letter of 

Map Amendment (LOMA) or Letter of Map Revision based on fill (LOMRF), but a Base Flood Elevation is not available in a Zone A, how can a 

Base Flood Elevation be obtained? 

Zone A identifies a Special Flood Hazard Area, studied by approximate methods, for which no 

Base Flood Elevations have been developed or provided as part of the Flood Insurance Study. 

Because an Elevation Certificate may be used to obtain a LOMA or LOMR-F, a surveyor may need 

to obtain a Base Flood Elevation at a building site in order to complete the Elevation Certificate. In 

some cases, Base Flood Elevations may already exist in the approximate Zone A area for which the 

Certificate is needed. There are several sources that a surveyor can check in order to obtain a Base 

Flood Elevation. The following list highlights three major sources for potential Base Flood 

Elevation data: 

1) State and local agencies: Check with the community floodplain management official. A Base 

Flood Elevation may have been developed as part of the floodplain development permit process 

before the building was constructed. Other local sources include the local public works 

department or the local transportation department, which may have developed flood data in 

designing sewer and storm drainage systems or local roads. Also, check with state agencies, 

such as Department of Natural Resources or a Geological Survey, which may have conducted 

flood studies using state funds, or the Department of Transportation. 

2) Other Federal Agencies: Information regarding Base Flood Elevations may be obtained from 

other Federal agencies involved in floodplain management. Some of the sources of Base Flood 

Elevation data may include the U.S. Army Corps of Engineers, U.S. Geological Survey, or the 

Department of Agriculture, Natural Resources Conservation Service. 

3) FEMA may have detailed flood information that has not yet been incorporated into the 

community’s Flood Insurance Study. Data requests should be directed to the FEMA Map 

Assistance Center at 1-877-FEMA MAP. In some circumstances FEMA can calculate a Base 

Flood Elevation if the data to develop the Base Flood Elevation is available in the back-up data 

to the Flood Insurance Study. 

In some cases, a Base Flood Elevation may have to be developed for the building site by a 

qualified engineer. A list of additional sources for existing data as well as guidance in 

developing Base Flood Elevations can be found in the publication, Managing Floodplain 

Development in Approximate Zone A Areas, A Guide for Obtaining and Developing Base (100-

year) Flood Elevations, FEMA 265/July 1995 

NOTE: If the Elevation Certificate is to be used to support a LOMA or LOMR-F request, the 

Certificate must be submitted along with the application, supporting data, signatures, and FEMA 

review fees (only for LOMR-Fs), as appropriate, before the LOMA or LOMR-F can be processed. 
National Flood Insurance Program Floodplain Management Bulletin 

Page 20 of 20 

Further Information

The Elevation Certificate and the Surveyor’s Guide to the Elevation Certificate can be found at 

http://training.nfipstat.com/ecsurveyor/. The Elevation Certificate can be downloaded at this site. 

Managing Floodplain Development in Approximate Zone A Areas, A Guide For Obtaining and 

Developing Base (100-year) Flood Elevations, FEMA 265, July 1995. Additional guidance pertaining 

to obtaining and developing Base Flood Elevations in Zone A can be found in this publication. 

Openings in Foundation Walls for Buildings Local in Special Flood Hazard Areas in accordance with 

the National Flood Insurance Program, Technical Bulletin 1-93, FIA-TB-1 (4/93). 

Protecting Building Utilities From Flood Damage, Principles and Practices for the Design and 

Construction of Flood Resistant Building Utility Systems, FEMA 348, November 1999. 

To obtain a copy of these publications, see the section on Ordering Information below. They are also 

available to view and download from http://www.fema.gov/library/prepandprev.shtm/mit. 

Comments 

Any comments on the Floodplain Management Bulletin should be directed to: 

 FEMA

 Mitigation Division 

 500 C St., SW 

 Washington, D.C. 20472 

Ordering Information 

• Copies of the Elevation Certificate and Instructions (FEMA Form 81-31) and the above listed 

publications are available from: 

FEMA Distribution Facility 

P.O. Box 2012, Jessup, MD 

20794-2012. 

FEMA’s Distribution Facility also accepts telephone requests (1-800-480-2520) and facsimile 

requests (301-362-5335). 

• Copies of the Floodplain Management Bulletins can also be obtained from the appropriate FEMA 

regional office.