Lowest floor at or above Base Flood Elevation in Special Flood Hazard Areas
FEMA P-2325 §Flood Hazard ProvisionsDescription
Homes located within a FEMA-designated Special Flood Hazard Area (SFHA) should be elevated so the lowest floor is at or above the Base Flood Elevation (BFE) from the FEMA Flood Insurance Rate Map. Many communities require 1-2 ft of additional freeboard above BFE. New construction in SFHAs must comply with IRC R322 / IBC 1612.
Why this exists
Compliance lowers risk of structural flood damage and substantially reduces flood-insurance premiums under the NFIP. FEMA's central design provision for flood-zone residential is the BFE-relative elevation requirement.
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
lowestFloorElevation | min | 0 | ft above BFE | Lowest floor must be at or above Base Flood Elevation (many jurisdictions add 1-2 ft freeboard) |
Categories
Source
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Continuous load path from roof to foundation · HUD RSDG §2.4
- Residential structural reliability targets 1-in-100 to 1-in-1000 annual probability of failure · HUD RSDG §2.5
- Residential floor live load: 40 psf minimum (30 psf sleeping rooms) · HUD RSDG §3.4
- Wind load design uses ASCE 7 basic wind speed for the locality · HUD RSDG §3.6
- Ground snow load for Virginia: 25 psf eastern, up to 40 psf western mountains · HUD RSDG §3.7
Last reviewed 2026-05-11.