Elevation / Freeboard
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.
A five-minute video that explains floodplain related terms that demonstrates the financial benefits to adding freeboard or elevating a building to a height higher than required as well as:
- Base Flood Elevation (BFE)
Building Elevation Requirements
Generally, newly constructed or placed structures in "A" or "V" type flood zones need to be elevated. Permits for new buildings issued under the Building Permit Allocation System (B-PASS), are required to be elevated six-inches higher than others (1.5 feet above flood levels). View more on reading a flood map.
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. View Substantial Improvement to learn more.
Elevation of the building is usually required, except for the following:
- Commercial use buildings are permitted to floodproof in lieu of elevation. However, floodproofing isn’t an option for commercial buildings used for residential purposes: hotel, motel, residential, patient housing, child/adult daycare etc.
- Historic structures: Historically Contributing Structures are buildings identified on a Historic Structure Survey maintained by the city’s Historic Architectural Review Commission (HARC), as authorized by the State of Florida’s Division of Historic Resources. Additions to contributing structures may require elevation, even if the historic portion of a home isn’t required to elevate. For more information on the historic structure exemption Historic Building Exemptions.
- Mobile/Manufactured Homes/Buildings, new or relocated
Newly constructed or placed buildings in "A" type flood zones need to be elevated to the Base Flood Elevation Plus 1-Foot. However, permits for new buildings issued under the Building Permit Allocation System (B-PAS), are required to elevated to Base Flood Elevation Plus 1.5-feet. In "V" type flood zones, the building’s lowest supporting 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.
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; either 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. This information is from HARC Guidelines-REVISED, page 38, Item Number 2, 2010.
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 four feet.
Insurance Savings Using Freeboard
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. 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.
Cost to Elevate
A rough estimate for the costs to elevate homes is:
- Concrete block home $120 to $140 square feet
- Woodframe building $72 square feet