Official substantial damage determination letters must include:

• Property information
• Substantial damage determination
• Consequences of the determination
• Permit requirements
• Contact information

Determination letters can also include:

• Requirements for participation in the NFIP
• The community’s flood damage prevention ordinance that is the basis for substantial damage determination and substantial improvement requirements

The substantial damage determination letter does not have to specify the precise percentage used, just that it is equal to or greater than 50%.