Summary of Coastal Construction Requirements 
and Recommendations

HOME BUILDERS GUIDE TO COASTAL CONSTRUCTION

Technical Fact Sheet No. 1.2


Purpose:  To summarize recommendations for exceeding National Flood Insurance Program (NFIP) regulatory 
requirements concerning coastal construction.


Key Issues

*   New construction* in coastal flood hazard areas (V Zone and A Zone) should be designed using the engineering 
standards (ASCE 24 and ASCE 7) or the International Residential Code (IRC), as applicable. Best practices must 
exceed the minimum NFIP requirements and must meet, or exceed, all community zoning and building code 
requirements. Repairs, remodeling, and additions must always meet NFIP and building code requirements for the 
part of the structure impacted. Should these costs exceed 50 percent of the fair market value of the structure, 
the entire building must be brought to local floodplain management and building code compliance. 

*   Engineering standards ASCE 24-05 and ASCE 7-10 are more stringent in V Zones than in A Zones, to protect 
against the increased flood, wave, flood-borne debris, and erosion hazards typical of V Zones.

*   For added protection, it is strongly recommended that buildings in flood zones that are subject to breaking waves 
between 1.5 and 3 feet as well as erosion and scour be designed and constructed to V Zone standards. These 
coastal areas, mapped as A Zones, may be subject to damaging waves and erosion and are often referred to as 
Coastal A Zones.   Buildings in these areas are typically constructed to the minimum NFIP A Zone requirements 
and have at least a 1-percent-annual-chance of sustaining major damage or being destroyed. This regulatory 
standard is known as the base flood. 

*   Buildings constructed to minimum NFIP A Zone standards and subject solely to shallow flooding (i.e., not subject 
to breaking waves greater than 1.5 feet or erosion) are still subject to flood damage and should be built with a 
first floor elevation above the BFE (usually at least one foot or greater), which is referred to as ?freeboard.*   

*   Following the recommendations in the following table will result in less damage to the building and may reduce 
flood insurance premiums (see the V Zone Risk Factor Rating Form in FEMA?s Flood Insurance Manual 
(http://www.fema.gov/nfip/manual.shtm).

The following table summarizes NFIP regulatory requirements and recommendations for exceeding those 
requirements for both (1) new construction and (2) repairs, remodeling, and additions.

For floodplain management purposes, new construction refers to structures for which construction began on or after 
the effective date of adoption of the community?s floodplain management ordinance. Substantial improvements, 
repairs of substantially damaged buildings, and some enclosures must meet the same floodplain management 
ordinance and building code requirements as new construction where such ordinances and codes have been adopted 
by the community.



Developed in association with the National Association of Home Builders Research Center




Coastal Construction Requirements and Recommendations

V Zone
Coastal A Zone
A Zone
Additional Resources
Foundation
Structural Fill
NFIP 60.3(e)(6)
Prohibited
Requirement:  Compac
tion where used; 
protect against scour 
and erosion.
Requirement:  Compac
tion where used; 
protect against scour 
and erosion.
IBC:  1804.4, App. G 401.1, 
App. G 401.2
IRC:  R322.3.2
ASCE:  ASCE 24 Sec. 2.4
Other:  FEMA TB #5
Solid Foundation 
Walls [see Fact 
Sheet Nos. 3.1, 
3.5] 
NFIP 60.3(c)(3)
Prohibited
Requirement:   
Flood vents must be 
installed to equalize 
pressures (see Fact 
Sheets Nos. 3.5 and 
8.1).
Recommendation:  An 
open foundation 
system should be 
used.
Requirement:   
Where used, the walls 
must allow floodwaters 
to pass between or 
through the walls using 
flood openings (see 
Fact Sheets Nos. 3.5 
and 8.1).
IBC:  1612.5.1
IRC:  R322.2.3
ASCE:  ASCE 24 Sec. 2.5, 
ASCE 7 Sec. 5.4.4.2
Other:  FEMA TB #5, FEMA 
550
Open Foundation 
[see Fact Sheet 
No. 3.1] 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Recommendation:  Site 
new construction 
landward of the long-
term erosion setback 
and landward of the 
area subject to erosion 
during the 1% coastal 
flood event.
Requirement:  All new 
construction shall be 
landward of the reach 
of the mean high tide; 
alteration of sand 
dunes and mangrove 
stands that increases 
the potential of flood 
damage is prohibited.
Recommendation:  Op
en foundations are 
recommended in 
Coastal A Zones.
Recommendation:  Op
en foundations are 
recommended in A 
Zones.
IBC:  1803.5.5
IRC:  R322.3.3
ASCE:  ASCE 7 Sec. 5.4.4.1, 
ASCE 24 Sec 4.5.5
Other:  FEMA TB #5
Lowest Floor 
Elevation (not in 
a V Zone)  
[see Fact Sheet 
No. 1.5] 
NFIP 60.3(c)
Not Applicable
Recommendation:  Ele
vate the bottom of the 
lowest horizontal 
structural member at, 
or above, BFE.
Requirement:  Top of 
floor must be at or 
above BFE.
Requirement:   
Top of floor must be at 
or above BFE.
IBC:  1603.1.7, 1612.5
IRC:  R105.3.1.1, R322.2.1, 
R322.1.5
ASCE:  ASCE 24 Sec. 1.5.2, 
ASCE 24 Sec. 2.5, ASCE 24 
Ch. 5, ASCE 24 Ch. 7
Other:  FEMA TB #5
Bottom Lowest 
Horizontal 
Structural 
Member  
[see Fact Sheet 
No. 1.4] 
NFIP 60.3(e)(4)
Requirement:   
Bottom of the lowest 
horizontal structural 
member of the first 
floor must be at, or 
above, the BFE (see 
Fact Sheet No. 1.5).
Recommendation:  Foll
ow the V Zone building 
elevation requirement.

Recommendation:   Th
e minimum 
recommendation is to 
follow the Coastal A 
Zone requirements. 
Users should consider 
following V Zone 
recommendations for 
the lowest horizontal 
structural member 
elevation to further 
minimize the risk of 
flood damage.
IBC:  1603.1.7, 1605.2.2, 
1605.3.1.2, 1612.4, 1612.5.2
IRC:  R322.3.2
ASCE:  ASCE 24 Sec. 4.4, 
ASCE 24 Sec. 2.5, ASCE 24 
Ch. 5
Other:  FEMA 55, FEMA TB 
#8, FEMA TB #5
Foundation
Orientation of 
Lowest 
Horizontal 
Structural 
Member

Requirement:   
Elevate the bottom of 
the lowest horizontal 
structural member at, 
or above, BFE. 

Recommendation:  If 
the orientation of the 
lowest horizontal 
structural member is 
parallel to the expected 
direction of waves, 
elevate the bottom of 
the member to or 
above BFE; If the 
orientation of the 
lowest horizontal 
structural member is 
perpendicular to the 
expected direction of 
waves, elevate the 
bottom of the member 
to BFE plus one foot. 
Diagonal bracing for 
decks, stairways, 
balconies and other 
attached structures 
should also be 
elevated at, or above, 
the BFE.
Recommendation:  Foll
ow the Coastal A Zone 
recommendation. 

IBC:  see ASCE 24
IRC:  R322.3.2
ASCE:  ASCE 24 Sec 4.4
Other:  FEMA TB #5
Freeboard  
[see Fact Sheet 
Nos. 1.1, 1.4]
Requirement:   
No NFIP requirement, 
but freeboard is 
required by IRC and 
ASCE.
Recommendation:  Fre
eboard is 
recommended in 
Coastal A Zones.
Note:  Per ASCE 24-05 
one foot of freeboard 
required for Risk 
Category II structures.
Recommendation:  Fre
eboard is 
recommended in A 
Zones.
Note:  One foot above 
BFE is required per 
IRC R322.2.1 Item #2 
for Coastal A Zones.
IBC:  see ASCE 24
IRC:  R322.2.1, R322.3.2
ASCE:  ASCE 24 Sec. 2.3

Enclosures 
Below the BFE 
(not in a V Zone)
Not Applicable
Recommendation:  If 
an enclosure is 
constructed, use 
breakaway walls, open 
lattice, or screening (as 
required in V Zones).
Requirement:   
If an area is fully 
enclosed, the 
enclosure walls must 
be equipped with 
openings to equalize 
hydrostatic pressure; 
the size, location, and 
covering of openings 
governed by regulatory 
requirements.
Recommendation:  If 
an enclosure is 
constructed, use 
breakaway walls, open 
lattice, or screening (as 
required in V Zones).
Requirement:   
If an area is fully 
enclosed, the 
enclosure walls must 
be equipped with 
openings to equalize 
hydrostatic pressure; 
the size, location, and 
covering of openings 
governed by regulatory 
requirements.
IBC:  1203.3.2, 1403.5, 
1612.4, 1612.5.1
IRC:  R322.2.2, R408.7
ASCE:  ASCE 24 Sec. 2.6, 
ASCE 24 Sec 4.6
Other:  FEMA TB #1
Enclosures 
Below the BFE 
(not in V Zones) 
[see Fact Sheet 
No. 8.1] 
NFIP 60.3(c)(5)
Prohibited,?except for 
breakaway walls, open 
wood lattice, and 
screening.
Not Applicable
Not Applicable
IBC:  1403.5, 1403.6, 1612.4, 
1612.5.2
IRC:  R322.3.2, R322.3.4, 
R322.3.5
ASCE:  ASCE 24 Sec. 4.6, 
ASCE 7 Sec. C5.3.3
Other:  FEMA 55, FEMA TB 
#5, FEMA TB #9
Foundation
Non Structural 
Fill
Requirement:   
Allowed for minor 
landscaping and site 
drainage as long as the 
fill does not interfere 
with free passage of 
flood waters and debris 
beneath the building, or 
cause changes in flow 
direction during coastal 
storms that could result 
in damage to buildings.
Recommendation:  Foll
ow the V Zone fill 
requirement.

Recommendation:  Foll
ow the V Zone fill 
requirement.

IBC:  803.11.1
IRC:  R322.14.2, R322.3.2
ASCE:  ASCE 24 Sec 1.5.4, 
45.4
Other:  FEMA TB #5
Use of Space 
Below BFE  
[see Fact Sheet 
No. 8.1]
Requirement:   
Allowed only for 
parking, building 
access, and storage
Requirement:   
Allowed only for 
parking, building 
access, and storage
Requirement:   
Allowed only for 
parking, building 
access, and storage
IBC:  1107.7.5, G105.7 (5), 
801.5, G103.5, G103.8
IRC:  R309.3, R322.1, 
R322.1.2, R322.1.3, 
R322.1.4, R322.1.4.1, 
R322.2.1, R322.2.2, 
R322.3.2, R322.3.5 
ASCE:  ASCE 24 1.5.2, 2.6, 
2.6.1, 2.6.2.1, 2.6.2.2, 4.6, 
4.6.1, 4.6.2
Utilities
Sanitary Sewer
NFIP 60.3(a)(6)(i) 
and 60.3(a)(6)(ii)



IBC:  1403.6, App. G 401.3
IRC:  R322.1.7, R P2602.2,  
R P3001.3, R P3101.5
ASCE:  ASCE 24 Sec. 7.3.4
Other:  FEMA 348, FEMA TB 
#4
Utilities  
[see Fact Sheet 
No. 8.3] 
NFIP 
60.3(a)(3)(iv)
Requirement:   
Must be designed, 
located, and elevated 
to prevent flood waters 
from entering and 
accumulating in 
components during 
flooding. Utility lines 
must not be installed or 
stubbed out in 
enclosures below BFE 
unless flood proofed to 
the extent practicable.
Requirement:  Electrica
l, heating, ventilation, 
plumbing, and air-
conditioning equipment 
and other service 
facilities to be designed 
and/or located as to 
prevent water from 
entering or 
accumulating within the 
components during 
periods of flooding.
Recommendation:  Foll
ow the V Zone utility 
recommendation
Requirement:  Electrica
l, heating, ventilation, 
plumbing, and air-
conditioning equipment 
and other service 
facilities to be designed 
and/or located as to 
prevent water from 
entering or 
accumulating within the 
components during 
periods of flooding.
IBC:  1403.6, 1612.4,  
App. G 701
IRC:  R322.1.6, IFGC 301.11, 
R G2404.7, R P2601.3,  
R P2602.2, R M1301.1.1,  
R M1401.5, R M1601.4.9,  
R M1701.2, R M2001.4,  
R M2201.6
ASCE:  ASCE 24 Ch. 7
Other:  FEMA 348, FEMA TB 
#4
Certification
Permits 
NFIP 60.3(b)(1)

Requirement:   
V Zone certificate, 
Breakaway Wall 
certificate, and 
Elevation Certificate.
Requirement:  Elevatio
n Certificate.
Requirement:  Elevatio
n Certificate.
IBC:  App. G 101.3, App. G 
103, App. G 104
IRC:  R104.2, R105, App. E, 
App. J
ASCE:  ASCE 24 Sec. 4.6, 
ASCE 7 Sec. C5.3.3
Other:  FEMA EMI IS-9
Certification
Elevation 
NFIP 60.3(b)(5)(i) 
and 60.3(e)(2)
Requirement:   
The lowest horizontal 
structural member 
must be at, or above, 
BFE; electrical, 
heating, ventilation, 
plumbing, and air-
conditioning 
equipment and other 
service facilities 
(including ductwork) 
must be designed 
and/or located so as 
to prevent water from 
entering or 
accumulating within 
the components 
during flooding (see 
Fact Sheet Nos. 
1.4,1.5, 8.3)
Recommendation:  Fo
llow the V Zone 
building elevation 
requirement.
Requirement:   
Top of lowest floor 
must be at, or above, 
BFE; electrical 
heating, ventilation, 
plumbing, and air 
conditioning 
equipment and other 
service facilities 
(including ductwork) 
must be designed 
and/or located so as 
to prevent water from 
entering or 
accumulating within 
the components 
during flooding (see 
Fact Sheet Nos. 1.4 
8.3)
Recommendation:    T
he minimum 
recommendation is to 
follow the Coastal A 
Zone requirements. 
Users should consider 
following V Zone 
recommendations for 
the lowest horizontal 
structural member 
elevation to further 
minimize the risk of 
flood damage.
Requirement:   
Top of the lowest floor 
must be at, or above, 
BFE; electrical 
heating, ventilation, 
plumbing, and air 
conditioning 
equipment and other 
service facilities 
(including ductwork) 
must be designed 
and/or located so as 
to prevent water from 
entering or 
accumulating within 
the components 
during flooding (see 
Fact Sheet Nos. 1.4, 
8.3) 
IBC: 110.3.3,1603.1.7, 
1612.5
IRC: R106.1.3, R322.1.2, 
R322.1.5, R322.2.1
ASCE: ASCE 24 Sec. 1.5.1, 
1.5.2, 4.4

Structure
Requirement:  Regist
ered engineer or 
architect must certify 
that the design and 
methods of 
construction are in 
accordance with an 
accepted standard of 
practice for meeting 
design requirements 
described under 
General Requirement 
(see Fact Sheet No. 
1.5)
Recommendation:  Fo
llow the V Zone 
requirement.

Recommendation:  Fo
llow the V Zone 
requirement.

IBC:  1604.1,1604.2, 1604.3
IRC:  R301.1, 
R301.1.3,R301.2
ASCE:  ASCE 7 Sec. 
1.3.1.3.3

Certification
Breakaway Walls  
[see Fact Sheet 
Nos. 1.5, 8.1] 
(also see 
Enclosures 
Below BFE) 
NFIP 60.3(e)(5)
Requirement:  
Walls must be designed 
to break free under 
larger of the following 
allowable stress design 
loads:  (1) design wind 
load, (2) design seismic 
load, or (3) 10 psf, 
acting perpendicular to 
the plane of the wall; if 
loading intended to 
cause collapse exceeds 
20 psf using allowable 
stress design, the 
breakaway wall design 
shall be certified; when 
certification is required, 
a registered engineer or 
architect must certify 
that the walls will 
collapse under a water 
load associated with the 
Base Flood and that the 
elevated portion of the 
building and its 
foundation will not be 
subject to collapse, 
displacement, or lateral 
movement under 
simultaneous wind and 
water loads.
Recommendation:  Bre
akaway walls are 
recommended with an 
open foundation in lieu 
of solid walls; if 
breakaway walls are 
used and enclose an 
area, flood openings 
are required (see Fact 
Sheet Nos. 3.1, 3.5).

IBC:  1612.5 (2.3)
IRC:  R322.3.4
ASCE:  ASCE 24 Sec. 4.6.1, 
4.6.2, 2.6.1.1, ASCE 7 Sec. 
5.3.3
Other:  FEMA TB #5, FEMA 
TB #9

Openings in 
Below-BFE Walls  
[see Fact Sheet 
Nos. 3.1, 3.5] 
(also see 
Enclosures 
Below BFE) 
NFIP 60.3(c)(5)
Not Applicable
Requirement:   
Unless the number and 
size of the openings 
meet regulatory 
requirements, a 
registered engineer or 
architect must certify 
that the openings are 
designed to 
automatically equalize 
hydrostatic forces on 
the walls by allowing 
automatic entry and 
exit of flood waters.
Requirement:   
Unless the number and 
size of the openings 
meet regulatory 
requirements, a 
registered engineer or 
architect must certify 
that the openings are 
designed to 
automatically equalize 
hydrostatic forces on 
the walls by allowing 
automatic entry and 
exit of flood waters.
IBC:  1203.4.12, G1001.4
IRC:  R322.2.2
ASCE:  ASCE 24 Sec. 2.6.1, 
2.6.2.1, 2.6.2.2
Other:  FEMA TB #1

Repairs, Remodeling, and Additions [See Fact Sheet No. 9.1]
Substantial 
Improvements 
and Repairs of 
Substantial 
Damage 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Requirement:  Must 
meet current NFIP 
requirements 
concerning new 
construction in V Zones 
except for siting 
landward of mean high 
tide (see Fact Sheet 
Nos. 1.4, 1.5, 2.2, 3.1, 
3.5, 8.1, 8.3).
Recommendation:  Foll
ow the V Zone 
requirement for 
building elevation and 
open foundations.
Requirement:  Must 
meet current NFIP 
requirements 
concerning new 
construction in A Zones 
(see Fact Sheet Nos. 
1.4, 3.1, 3.5, 8.1, 8.3).
Recommendation:  Ele
vate bottom of lowest 
horizontal structural 
member to  
or above BFE.
Requirement:  Must 
meet current NFIP 
requirements 
concerning new 
construction in A Zones 
(see Fact Sheet Nos. 
1.1, 3.1, 3.5, 8.1, 8.3) 
IBC:  1612.1, 1612.2, 3403.2, 
3404.2, 3405.2, 3405.3, 
3405.4
IRC:  R322.1.6, R322.3.1
ASCE:  ASCE 24 Sec. 4.3, 
ASCE 7 Sec. 1.6
Other:  FEMA P-758

Repairs, Remodeling, and Additions [See Fact Sheet No. 9.1]
Lateral Additions 
That Constitute 
Substantial 
Improvement 
NFIP 60.3(e)(5)
Requirement:   
Both the addition and 
the existing building 
must meet current NFIP 
requirements 
concerning new 
construction in V Zones 
(see Fact Sheet Nos. 
1.4, 1.5, 2.2, 3.1, 3.5, 
8.1, 8.3).
Recommendation:  Foll
ow V Zone requirement 
for building elevation 
and open foundations 
for the addition and the 
existing building.
Requirement:   
Only additions must 
meet current NFIP 
requirements 
concerning new 
construction in A Zones 
(see Fact Sheet Nos. 
1.4, 1.5, 3.1, 3.5, 8.1, 
8.3), provided the 
existing building is not 
subject to any work 
other than cutting an 
entrance in a common 
wall and connecting the 
existing building to the 
addition; if any other 
work is done to the 
existing building it too 
must meet current 
NFIP requirements for 
new construction in A 
Zones. 
Recommendation:  Ele
vate bottom of lowest 
structural member of 
the addition to or above 
BFE (same for the 
existing building if it is 
elevated).
Requirement:   
Only additions must 
meet current NFIP 
requirements 
concerning new 
construction in A Zones 
(see Fact Sheet Nos. 
1.4, 2.2, 3.1, 3.5, 8.1, 
8.3), provided the 
existing building is not 
subject to any work 
other than cutting an 
entrance in a common 
wall and connecting the 
existing building to the 
addition; if any other 
work is done to the 
existing building it too 
must meet current 
NFIP requirements for 
new construction in A 
Zones.
IBC:  3403.2, 3412.2.3, 
3405.3
IRC:  R322.3.1
ASCE:  ASCE 7 Sec. 1.6
Other:  FEMA TB #1,  
FEMA TB #5, FEMA TB #9, 
FEMA 550

Lateral Additions 
That Do Not 
Constitute 
Substantial 
Improvement 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Recommendation:  M
ake addition 
compliant with current 
NFIP requirements for 
V Zone construction.
Requirements:  Post-
FIRM existing building 
*   the addition must 
meet NFIP 
requirements in effect 
at time the building 
was originally 
constructed. Pre-
FIRM existing building 
*   NFIP requirements 
concerning new 
construction are not 
triggered (see Fact 
Sheet Nos. 1d, 1e, 
2b, 3a, 3e, 8a, 8c) 


Recommendation:  Fo
llow V Zone 
requirement for 
building elevation and 
open foundations for 
the addition and the 
existing building.
Requirements:  Post-
FIRM existing building 
*   the addition must 
meet NFIP 
requirements in effect 
at the time the 
building was originally 
constructed (see Fact 
Sheet Nos. 1d, 1e, 
2b, 3a, 3e, 8a, 8c). 
Pre-FIRM existing 
building -- NFIP 
requirements 
concerning new 
construction are not 
triggered. 
Recommendation:  El
evate bottom of 
lowest horizontal 
structural member to 
or above BFE (same 
for existing building if 
it is elevated) (see 
Fact Sheet No. 1d)
Requirements:  Post-
FIRM existing building 
*   the addition must 
meet NFIP 
requirements in effect 
at the time the 
building was originally 
constructed (see Fact 
Sheet Nos. 1d, 1e, 
2b, 3a, 3e, 8a, 8c). 
Pre-FIRM existing 
building -- NFIP 
requirements 
concerning new 
construction are not 
triggered. 
BC:  3403.2, 3412.2.3, 
3405.3
IRC:  R322.3.1
ASCE:  ASCE 7 Sec. 1.6
Other:  FEMA TB #1,  
FEMA TB #5, FEMA TB #9, 
FEMA 550

Repairs, Remodeling, and Additions [See Fact Sheet No. 9.1]
Vertical 
Additions That 
Constitute 
Substantial 
Improvement 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Requirement:  Entire 
building must meet 
current NFIP 
requirements 
concerning new 
construction in V 
Zones (see Fact Sheet 
Nos. 1d, 1e, 2b, 3a, 3e, 
8a, 8c).
Recommendation:  Foll
ow V Zone 
requirements for 
building elevation and 
open foundations.
Requirement:  Entire 
building must meet 
current NFIP 
requirements 
concerning new 
construction in A Zones 
(see Fact Sheet Nos. 
1d, 1e, 2b, 3a, 3e, 8a, 
8c). 

Recommendation:  Ele
vate bottom of lowest 
horizontal structural 
member to or above 
BFE (same for existing 
building if it is elevated) 
(see Fact Sheet No. 
1d).
Requirements:  Post-
FIRM existing building 
*   the addition must 
meet NFIP 
requirements in effect 
at the time the building 
was originally 
constructed (see Fact 
Sheet Nos. 1d, 1e, 2b, 
3a, 3e, 8a, 8c). Pre-
FIRM existing building -
- NFIP requirements 
concerning new 
construction are not 
triggered.

IBC:  3405.3.1, 3405.4, 
3405.5
IRC:  N/A
ASCE:  N/A

Vertical 
Additions That 
Do Not 
Constitute 
Substantial 
Improvement 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Recommendation:  M
ake the addition 
compliant with current 
NFIP requirements for 
V Zone construction.
Requirements:  Post-
FIRM existing building 
*   the addition must 
meet NFIP 
requirements in effect 
at the time the 
building was originally 
constructed. Pre-
FIRM existing building 
-- NFIP requirements 
concerning new 
construction are not 
triggered (see Fact 
Sheet Nos. 1.4, 1.5, 
2.2, 3.1, 3.5, 8.1, 8.3).

Recommendation:  Fo
llow the V Zone 
requirement for 
building elevation and 
open foundations for 
the existing building.
Requirements:  Post-
FIRM existing building 
*   the addition must 
meet NFIP 
requirements in effect 
at the time the 
building was originally 
constructed (see Fact 
Sheet Nos. 1.4, 1.5, 
2.2, 3.1, 3.5, 8.1, 8.3). 
Pre-FIRM existing 
building -- NFIP 
requirements 
concerning new 
construction are not 
triggered.

Recommendation:  El
evate bottom of 
lowest horizontal 
structural member at, 
or above, BFE (same 
for the existing 
building if it is 
elevated) (see Fact 
Sheet No. 1.4).
Requirements:  Post-
FIRM existing building 
*   the  addition must 
meet NFIP 
requirements in effect 
at the time the 
building was originally 
constructed (see Fact 
Sheet Nos. 1.4, 1.5, 
2.2, 3.1, 3.5, 8.1, 8.3). 
Pre-FIRM existing 
building -- NFIP 
requirements 
concerning new 
construction are not 
triggered.

IBC:  3405.3.1, 3405.4, 
3405.5
IRC:  N/A
ASCE:  N/A
Repairs, Remodeling, and Additions [See Fact Sheet No. 9.1]
Elevating on New 
Foundation 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Requirement:   
New foundation must 
meet current NFIP 
requirements 
concerning new 
construction in V 
Zones; the building 
must be properly 
connected and 
anchored to the new 
foundation.
Note:  Repairing a 
foundation that does 
not constitute a 
substantial 
improvement does not 
require current 
compliance, but 
compliance to the year 
of construction.
Recommendation:  Foll
ow the V Zone 
requirement for 
building elevation and 
open foundations.
Requirement:  New 
foundation must meet 
current NFIP 
requirements 
concerning new 
construction in A 
Zones; the building 
must be properly 
connected and 
anchored to the new 
foundation.

Recommendation:  Ele
vated bottom of lowest 
horizontal structural 
member to or above 
BFE (see Fact Sheet 
No. 1d).
Requirement:  New 
foundation must meet 
current NFIP 
requirements 
concerning new 
construction in A 
Zones; the building 
must be properly 
connected and 
anchored to the new 
foundation.

IBC:  1808.1, 1808.2, 1808.3, 
1808.6, 1808.6.1
IRC:  R401.1, R401.2, 
R401.3, R401.4, R401.4.1
ASCE:  ASCE 24 Sec. 1.5.3, 
1.5.3.1, 1.5.3.2, 1.5.3.3, 
ASCE 7 Sec. 1.6
Other:  FEMA 550, FEMA TB 
#1, FEMA TB #5

Enclosures 
Below Buildings?
When Enclosure 
Constitutes a 
Substantial 
Improvement 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Requirement:  
Both the enclosure and 
the existing building 
must meet current 
NFIP requirements for 
new construction in V 
Zones (see Fact 
Sheets Nos. 1.4, 1.5, 
2.2, 3.1, 8.1, 8.3).
Recommendation:  Foll
ow the V Zone 
requirement for 
building elevation and 
open foundations.
Requirement:  Both the 
enclosure and the 
existing building must 
meet current NFIP 
requirements for new 
construction in A 
Zones (see Fact 
Sheets Nos. 1.4, 1.5, 
2.2, 3.1, 8.1, 8.3).
Recommendation:  Ele
vated bottom of lowest 
horizontal structural 
member at, or above, 
BFE (see Fact Sheet 
No. 1.4).
Requirement:  Both the 
enclosure and the 
existing building must 
meet current NFIP 
requirements for new 
construction in A 
Zones (see Fact 
Sheets Nos. 1.4, 1.5, 
2.2, 3.1, 8.1, 8.3).
IBC:  1612.1, 3404.2
IRC:  R322.1, R322.1.8, 
R322.3.5
ASCE:  ASCE 24 Sec. 4.6, 
ASCE 7 Sec. 1.6
Other:  FEMA TB #5, FEMA 
TB #9

Enclosures 
Below Buildings?
When Enclosure 
Does Not 
Constitutes a 
Substantial 
Improvement 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Recommendation:  Ma
ke the enclosure 
compliant with current 
NFIP requirements for 
new V Zone 
construction.
Requirement:  Post-
FIRM existing building 
*   the enclosure must 
meet NFIP 
requirements in effect 
at the time the building 
was originally 
constructed. Pre-FIRM 
existing building -- 
NFIP requirements 
concerning new 
construction are not 
triggered (see Fact 
Sheet No. 8.1).

Recommendation:  Co
nstruct only breakaway 
enclosures; install flood 
openings in the 
enclosure; do not 
convert the enclosed 
space to habitable use.
Requirement:  Post-
FIRM existing building 
-- the enclosure must 
meet NFIP 
requirements in effect 
at the time the building 
was originally 
constructed. Pre-FIRM 
existing building -- 
NFIP requirements 
concerning new 
construction are not 
triggered (see Fact 
Sheet Nos. 3.5, 8.1).
Recommendation:  Inst
all flood openings in 
the enclosure; do not 
convert the enclosed 
space to habitable use.
Requirement:  Post-
FIRM existing building 
*   the enclosure must 
meet NFIP 
requirements in effect 
at the time the building 
was originally 
constructed. Pre-FIRM 
existing building -- 
NFIP requirements 
concerning new 
construction are not 
triggered (see Fact 
Sheet Nos. 3.5, 8.1).

IBC:  1612.1, 3404.2
IRC:  N/A
ASCE:  ASCE 24 Sec. 4.6
Other:  FEMA TB #1,  
FEMA TB #5, FEMA TB #9

Repairs, Remodeling, and Additions [See Fact Sheet No. 9.1]
Reconstruction 
of Destroyed or 
Razed Building 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Requirement:   
Where the entire 
building is destroyed, 
damaged, or 
purposefully 
demolished or razed, 
the replacement 
building must meet 
current NFIP 
requirements 
concerning new 
construction in V 
Zones, even if it is 
built on the foundation 
from the original 
building (see Fact 
Sheet Nos. 1.4, 1.5, 
9.1).
Recommendation:  Fo
llow the V Zone 
requirement for 
building elevation and 
open foundations.
Requirement:  Where 
the entire building is 
destroyed, damaged, 
or purposefully 
demolished or razed, 
the replacement 
building must meet 
current NFIP 
requirements 
concerning new 
construction in A 
Zones, even if it is 
built on the foundation 
from the original 
building (see Fact 
Sheet Nos. 1.4, 9.1). 
Requirement:   
Where the entire 
building is destroyed, 
damaged, or 
purposefully 
demolished or razed, 
the replacement 
building must meet 
current NFIP 
requirements 
concerning new 
construction in A 
Zones, even if it is 
built on the foundation 
from the original 
building (see Fact 
Sheet Nos. 1.4, 9.1).
IBC:  1810.1.2, 105.1, K103.1
IRC:  R105.1, AJ501.3, 
AJ501.4, AJ501.5.1, AJ501.5, 
AJ501.5.1, AJ501.5.2, 
AJ501.5.3, AJ501.5.3.1, 
AJ501.5.3.2, AJ501.5.3.3, 
AJ501.5.3.4 AJ501.5.3.5, 
AJ501.6, AJ501.7, AJ501.8, 
AJ501.8.1, AJ501.8.2, 
AJ501.8.3
ASCE:  N/A
Other:  FEMA 550

Moving Existing 
Building 
NFIP 60.3(e)(5) 
and 60.3(c)(5)
Requirement:   
Where the existing 
building is moved to 
new location or site, 
the relocated building 
must meet current 
NFIP requirements 
concerning 
construction in V 
Zones (see Fact 
Sheet Nos. 1.4, 1.5, 
9.1).
Recommendation:  Fo
llow the V Zone 
requirement for 
building elevation and 
open foundations.
Requirement:  Where 
the existing building is 
moved to new 
location or site, the 
relocated building 
must meet current 
NFIP requirements 
concerning 
construction in A 
Zones (see Fact 
Sheet Nos. 1.4, 9.1).
Recommendation:  El
evate bottom of 
lowest horizontal 
structural member at, 
or above, BFE (see 
Fact Sheet No. 1.4).
Requirement:  Where 
the existing building is 
moved to new 
location or site, the 
relocated building 
must meet current 
NFIP requirements 
concerning 
construction in A 
Zones (see Fact 
Sheet Nos. 1.4, 9.1). 
IBC:  3410.1
IRC:  AE102.6
ASCE:  ASCE 7 Sec. 1.6
Other:  FEMA 550

Manufactured Housing
General



IRC:  R322.1.9, App. AE101
ASCE:  Not Applicable
Other:  FEMA 85