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Why is Base Flood Elevation (BFE) important to understand and discuss with a builder or seller when looking to purchase a coastal home?
The answer is simple, the cost of insuring your new home will vary greatly based on how high the home is constructed on a specific lot located within FEMA’s flood zone map. It is a big part of the cost of ownership on an ongoing basis.

Let us start with understanding (BFE)

FEMA defines the Base Flood Elevation (BFE) as the expected computed elevation to which the flood is anticipated to rise during the base flood.
Basically, that means how high the water will rise around a home during a 100-year flood event. Statistically, there is a 1{6a51be1615a1999eb74da11a62d3df2f372bacaf00f5b4884731ce93c5b731cf} chance every year that there will be a flood that will reach the max height detailed on the FEMA maps for any specific house.
The Base Flood Elevation is a baseline pulled together from historic weather data, local topography, and the best science available at the time. It’s a reasonable standard to insure against, but it is not a guarantee that it will flood only 1 time every 100 years and the flood will look exactly like it does on the maps.
BFEs are shown on FEMA’s Flood Insurance Rate Maps (FIRMs) and in the Flood Insurance Study (FIS) which are published by the Map Service Center for almost every community.
The land area covered by the base flood is called the Special Flood Hazard Area (SFHA) on FEMA’s maps. The SFHA is the area where the National Flood Insurance Program’s (NFIP’s) floodplain management regulations must be enforced and the area where the mandatory purchase of flood insurance applies. The SFHA includes flood Zones A, AO, AH, A1-30, AE, A99, AR, AR/A1-30, AR/AE, AR/AO, AR/AH, AR/A, VO, V1-30, VE, and V. So, if you are in one of those zones, it’s a good bet you need flood insurance and a BFE.
Mistakes calculating the BFE can really cost you through higher insurance premiums resulting from an incorrect policy rating or by denial of a LOMA removal request. The cost of an accurate elevation certificate is well worth it when you have the assurance that the BFE is correct. So, you cannot just look at the FEMA map and get the right number. Only by using the map and the FIS together with some specific measurement techniques can you get it right.
Be sure to ask or pay for a recent survey that details the correct BFE for a particular property you are interested in purchasing. You should ask for a recent “elevation certificate” completed by a licensed surveyor in your market area.

Next let us review how high a home should be built above (BFE)

Now that you have located a property or exiting home to purchase and understand the current (BFE) for the property, you need to understand how high the home is built above (BFE) to minimize the cost of flood insurance for the building.
Insurance companies know that during a storm or flood event, the rise in water will also included wave action. (BFE) levels only represent the water level as a flat line or think of it as a rise in water level on a completely calm day with zero wind. The water rises but is smooth as glass.
That is rarely if ever the case and when you combine the (BFE) water level with the wave action you arrive at the “water crest elevation.” So, when you consider how high a home needs to be built above (BFE) you must include the wave action. The higher you build above (BFE) less chances the home will be damaged by flooding and wave action during a storm event.

See picture below for reference:

The distance from the top of the wave height and the bottom most structural board of a home is called “Freeboard” This term is a nautical term used to describe how deep a ship is displacing water based on the weight carried by a ship.

The higher the freeboard height for any giving building results in lower flood insurance cost.

See graph below for reference:

If you need more information about the importance of “Free Board” feel free to call us @ 214.451.7579 ask for Michael Murray