There is no need to raise your building if no work is being performed. An existing business may remain at its current elevation. However, if your construction project meets the definition of a “substantial improvement” or “substantial damage”, you will be required to elevate your structure to the new elevation standards established by the REAL rules. As an alternative, you may dry flood proof the lower floor, although it should be noted that dry flood proofing an existing building not originally designed for the hydrostatic pressure of floodwaters is not likely to be feasible.