Glossary

Base flood elevation (BFE)

The height, in feet above a standard reference level, that floodwater is expected to reach in a flood with a 1% chance of occurring in any year.

Also called: BFE, 100-year flood elevation

Base flood elevation is the computed height that water is expected to reach in the base flood, the flood with a 1% annual chance. FEMA shows it on flood insurance rate maps for many high-risk zones, such as AE, AH and VE. Zone A, where detailed analysis has not been done, has no BFE, and Zone AO shows flood depths instead.

Communities use the BFE to set minimum building heights. New and substantially improved buildings in the high-risk area must usually have the lowest floor at or above the BFE, and many communities add "freeboard," an extra foot or more. A surveyor or engineer records your lowest-floor elevation against the BFE on an elevation certificate.

Insurance pricing used to turn heavily on the gap between your floor and the BFE. Under Risk Rating 2.0, NFIP premiums no longer depend on it; the rate reflects features such as first-floor height and foundation type, plus flood frequency from several types of flooding. The BFE still drives permits and building requirements, though, and it is not a ceiling. A flood can rise above the base flood, so a house built exactly at the BFE has little margin. The guide on elevating a home and other flood mitigation explains what raising a home can achieve.

Last reviewed October 10, 2026

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Related terms

Flood zone A map designation, such as Zone AE, VE or X, that classifies a property's flood risk and helps decide whether a lender will require flood insurance. Elevation certificate A form completed by a licensed surveyor, engineer or architect that records a building's key elevations against the mapped base flood elevation. Special flood hazard area (SFHA) The land FEMA maps as having at least a 1% chance of flooding in any year, where lenders must require flood insurance on federally backed mortgages. Flood insurance rate map (FIRM) FEMA's official map of a community showing flood zones, base flood elevations and floodways, which lenders use to decide whether flood insurance is required. Risk Rating 2.0 FEMA's current method of pricing NFIP flood policies by each home's own flood risk and rebuilding cost rather than mainly by flood zone and elevation.

Related guides

What flood insurance covers in a basement NFIP flood insurance covers only a short list of basement items, like the furnace, sump pump and unfinished drywall. What is excluded and how to fill the gaps. Elevation certificates and your flood premium What a FEMA elevation certificate records, who must have one, whether it lowers an NFIP premium under Risk Rating 2.0, and how to find or order one. Elevating a home and other flood mitigation How elevation, flood openings, raised equipment, floodproofing and buyouts work, what each does to flood insurance premiums, and where the money comes from. Flood zones and FEMA flood maps explained What the A, V, X and D flood zones mean, how to look up your address on a FEMA map, what a zone changes for your lender, and how to contest one with a LOMA. Risk Rating 2.0: how NFIP prices flood insurance now Since 2021 FEMA prices NFIP flood policies by each property's own flood risk and rebuild cost, not by zone. What drives your rate, the 18% cap, how to lower it.