The retrofitting of a structure typically is needed when a structure has suffer some damage due an a extraordinary event, such as an earthquake, hurricane, flooding, fire, explosion, corrosion, etc. or when the life span of the structure has been reached and it needs to be updated to current building codes.

The first part required for the retrofitting of a structure to perform the structures evaluation (mentioned before), and then, designing the appropriate retrofitting, for which serval methods can be used from replacing, reinforcing, or adding structural members, or using supplementary devices such as seismic isolation.