Lowest Floor Elevation - the measured distance of a building's lowest floor above the National Geodetic Vertical Datum (NGVD) or North American Vertical Datum (NAVD) as specified on the Flood Insurance Rate Map. The LFE is a critical measurement used to determine flood insurance premium rates under the National Flood Insurance Program. For buildings with basements, the LFE is the basement floor elevation. For buildings without basements, it's the elevation of the lowest floor including any attached garage or enclosure. A higher LFE relative to the Base Flood Elevation results in lower insurance premiums.