The City of Key West, Florida

The Southernmost City in the Continental United States

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Elevation/Freeboard

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Update: On March 23, 2016, the City held a Flood Mitigation Workshop with professionals from Arcadis Design & Consultancy who have a great deal of experience with the flood mitigation grant process. Click here to view a nearly two-video recording of this very informative event. 

 When?

How high?

Should I Elevate Higher?

Helpful Publications

 freeboard video graphic  

A five-minute video that explains floodplain related terms such as:

  • FIRMs
  • Pre-FIRM
  • Base Flood Elevation (BFE)
  • Freeboard

... and demonstrates the financial benefits to adding freeboard or elevating a building to a height higher than required.

Click here to watch.


When Building Elevation is Required?

  • New Construction
    • Generally, newly constructed or placed structures in "A" type flood zones need to be elevated.  (How to Read Flood Maps)
      • However, permits for new buildings issued under the Building Permit Allocation System (B-PASS), are required to be elevated six-inches higher (1.5' above flood levels).
  • Substantial Improvement/Renovation
    • Buildings constructed prior to the creation of flood maps (prior to 1975) lose their grandfathered status once they've been improved by 50% or more of the building's market value.  (See Substantial Improvement)
    • Mobile/Manufactured Homes/Buildings, new or relocated

 

How High?

  • New Construction
    • Newly constructed or placed buildings in "A" type flood zones need to be elevated to the Base Flood Elevation Plus 1-Foot. (How to Read Flood Maps)
      • However, permits for new buildings issued under the Building Permit Allocation System (B-PASS), are required to elevated to Base Flood Elevation Plus 1.5-feet.
      • In "V" type flood zones, the lowest building cross-member must be to Base Flood Elevation Plus 1-Foot.
    • Mobile/Manufactured or Relocated Homes/buildings
      • In a mobile home park, must be elevated so the bottom of the frame at least to the Base Flood Elevation level for the site.
      • Not in a mobile home park, the interior Finished First Floor must be to Base Flood Elevation Plus 1-Foot.
  • Historic District
    • Elevation of finished floor above grade Applications for buildings with the first finished floor above the minimum height necessary to comply with federal flood regulations will not be approved unless the applicant demonstrates that such elevation does not interfere• with the essential form and integrity of properties in the neighborhood. In situations wherein parking is proposed below the first finished floor, HARC shall consider how visible the parking is from the public right-of-way; :ether the parking area is enclosed or otherwise concealed by walls louvers, lattice, landscaping or other features; and whether fill and/or berms are used to minimize the gap between the first finished floor and the crown of the nearest road. [HARC Guidelines-REVISED, p.38, Item #2, 2010 ]

 

Should I Elevate Higher (Freeboard)?

"Freeboard" is the height of a building above the Base Flood Elevation for a specific site. Regulations often require at least 1-foot of freeboard for elevated buildings.

Each foot of freeboard lowers flood insurance rates significantly, up to a maximum of three feet.

Once an elevation project is planned, the cost of raising the building another couple of feet is negligible compared to the perpetual savings on flood insurance.  [Tip: The insurance industry rounds the height measurement to the nearest foot.  So if you can't elevate another full foot, aim for the half-foot mark to get insurance credit for another full foot.]

Click here to watch a five-minute video demonstrating the savings achievable with freeboard.

Cost to Elevate

A rough estimate for the costs to elevate homes is:

  • Woodframe building $72sf
  • Concrete block home $120-140sf

Helpful Publications:

FEMA's Chapter on Building Elevation

Homeowner's Guide to Retrofitting

Improving Connections in Elevated Coastal Residential Buildings

FEMA P-347, Above the Flood: Elevating your Floodprone House (2000)

FEMA P-55, Coastal Construction Manual: Principles and Practices of Planning, Siting, Designing, Constructing, and Maintaining Residential Buildings in Coastal Areas (4th ed.)

Manhole Cover Elevations - A handy quick reference showing the elevation of manhole covers above sea level (not for regulatory purposes).

 

 

 

 

 

 

 

 

 

 

 

Contact Us

Scott Fraser,
FEMA Coordinator/Floodplain Administrator
Building Department
1300 White St
Key West, FL 33040
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