The New Jersey Department of Community Affairs regulation NJAC 5:23-6.32 (a) states "Any addition to a building or structure shall comply with the requirements of the Uniform Construction code applicable to new construction.” Therefore, if you would like to add an addition to your home that is located in a floodzone, your home must now meet the requirements of new construction in that floodzone and be elevated above the local design flood elevation (the FEMA base flood elevation plus1 foot of additional freeboard). *This is regardless of the cost of the addition/substantial improvement determination.