More stringent requirements adopted by the local community or State take precedence over the minimum regulatory requirements established for flood insurance availability. These measures take a variety of forms and generally include zoning, subdivision, or building requirements, and special-purpose floodplain ordinances. The minimum Federal requirements affect existing buildings only when an existing building is substantially damaged or improved. There may also be situations where a building has been constructed in accordance with a local floodplain management ordinance, and the owner subsequently alters it in violation of the local building code, without a permit. Such unapproved modifications to an existing building may not meet the minimum Federal requirements.
Substantial damage is determined regardless of the actual repair work performed.
Substantial improvement or damage does not, however, include any project for improvement of a building to correct existing violations of State or local health, sanitary, or safety code specifications identified by local code enforcement officials and that are the minimum necessary to assure safe living conditions. The local floodplain management regulations required by the NFIP apply only in SFHAs. However, communities may regulate development in areas of moderate flood hazard. NFIP standards and policies are reviewed periodically and revised whenever appropriate. If the ground around the supporting posts or pilings is within the floodplain, the building is still at risk.