New Hampshire Flood Zone Building Requirements

Under RSA 155-A, the New Hampshire State Building Code adopts the International Building and Residential Codes, including ASCE 24 flood-resistant construction standards. Municipalities participating in NFIP must adopt floodplain management ordinances regulating Special Flood Hazard Areas (SFHA) per FEMA's 44 CFR 60.3. State law requires structures in SFHAs to meet base flood elevation requirements, use flood-resistant materials, and obtain elevation certificates. RSA 482-A also regulates wetland and floodplain alterations through NHDES dredge-and-fill permits. The state code floor preempts weaker local construction standards, though stricter local floodplain rules are permitted.

Violations may result in loss of NFIP eligibility for the community, denial of flood insurance, building code citations, and required elevation or removal of structures.