Basement

The purpose of this page is to define basements, a commonly used term in floodplain management.

Definition/Description

Any area of the building having its floor subgrade (below ground level) on all sides. The lowest floor of a residential building including basement must be above the Base Flood Elevation (BFE). Basements below the BFE are only allowed in communities that have obtained a basement exception from FEMA. Floodproofed non-residential basements are allowed.

NFIP Requirement

• 59.1 - Definition
• 60.3 - Flood plain management criteria for flood-prone areas
  • (c)(2) - Elevation Requirements for Residential Buildings
  • (c)(3) - Requirements for Nonresidential Buildings

Guidance

• IS-9 Managing Floodplain Development Through The National Flood Insurance Program (NFIP) (page 5-39) 
• Ensuring That Structures Built on Fill In or Near Special Flood Hazard Areas Are Reasonably Safe From Flooding (FIA-TB-10)
• Below-Grade Parking Requirements for Buildings Located in Special Flood Hazard Areas (FIA-TB-6)

Related Keywords

• Crawlspace
• Lowest Floor

Special Topic Resources

• Basement exceptions  
  • 60.6 (b) and ( c)
  • Federal Register Vol. 51, No.60, March 28, 1986, Proposed Rule, pp. 10746-10747