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What is a basement ? According to FEMA Technical Guide =Requirements for Flood Openings in Foundation Walls and Walls of Enclosures

  • 1.  What is a basement ? According to FEMA Technical Guide =Requirements for Flood Openings in Foundation Walls and Walls of Enclosures

    Posted 12 days ago
    Edited by Tirza Austin 12 days ago

    What is a basement?

    Does it have to have a minimum headroom?

    The rest of the world thinks of a basement as being an occupiable space.

    The FEMA Technical Guide =Requirements for Flood Openings in Foundation Walls and Walls of Enclosures on page 5 lists a definition.

    Basement: Area of a building that has its floor subgrade (below ground level) on all sides. NFIP
    regulations do not allow basements to extend below the base flood elevation (BFE) except in
    dry-floodproofed, non-residential buildings.

    There is no height guidance-  it could be only 2 feet tall as long as all four sides have the adjacent grade higher than the crawlspace floor.

    Most of the Flood Plain administrators recognize that this definiton does not apply for a crawlspace of 3 feet height.

    However I have one local jurisdiction that uses this to define a basement- even if it is only 2 feet tall.

    Once they define the crawlspace as being a basement, now the crawlspace floor becomes basement floor,

    and therefore the crawlspace (aka basement) floor must be at the FPG elevation.

    However with this definition, there never would occur the instance shown in the diagram  on page 13 of the guide.

    Can the code be amended to reflect some actual usable height criteria with the basement defintion- similar to the Residential code which requires 6'-8" height minimum? 



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    Paul Kimmerle P.E., M.ASCE
    OWNER
    Kimmerle Engineering
    Hudson IN
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