Step 4: Triage the damaged areas

It is important to quickly determine where people can make repairs and where reconstruction needs to account for mitigation opportunities. Where large areas are affected or the time is tight, an aerial or rapid building condition assessment can collect some preliminary data needed to help set priorities. The assessment should categorize properties into one of three categories:

  • A – Apparently safe: No exterior signs of structural damage. People can be allowed back in, but they will need building permits for repairs.
  • B – Building obviously substantially damaged: The building is gone, it has collapsed, or it is missing one or more walls. The building cannot be reoccupied without major structural work.
  • C – Could be substantially damaged: The building may be substantially damaged, but such damage is not obvious. More time and a closer assessment is needed to determine its condition.

Triage is important to help focus resources where they’re most needed. Areas that are obviously destroyed do not need building by building evaluations. Areas that had minimal damage are not likely to be targets for redevelopment. Those residents could be allowed to begin cleaning up and repairing right away.

Where it is not clear how bad the damage is (Category C buildings), more time is needed to determine if the properties are substantially damaged.

One rule of thumb that has been used is to consider all buildings with more than two feet of water over their first floors as Category C buildings. This does not mean that they are substantially damaged – only that they warrant a closer look before residents are allowed to begin cleaning up and repairing.


  • Most communities or counties conduct damage assessments following a disaster. The Red Cross may conduct a similar assessment. These are intentionally quick, but they may provide enough information for some preliminary triage. Check with the local emergency manager.
  • Unit 10.A. in FEMA 480 discusses a building condition survey. Figure 10–2a. provides a manual approach that has generally been replaced by FEMA’s Substantial Damage Estimator. The initial triage does not need to be so detailed, but eventually each Category C building will need such an evaluation (see also Step 1).
Conway was hit with different types of flooding in different areas, but one area had the more damage than the others. Residents of that area were not allowed to initiate repairs until a mitigation plan was prepared. This was done with a City Council resolution passed before the water went down.