Nothing in this chapter shall prevent the restoration of a nonconforming structure partially destroyed by fire, explosion, act of God or act of public enemy, to an extent not exceeding 50% of its current market replacement value at the time of the casualty, or prevent the continuance of the use of such structure or part thereof as such use existed at the time of destruction of the structure or part thereof or prevent a change of the existing use under the limitations provided in this section. However, any structure destroyed in the manner aforesaid to an extent exceeding 50% of its current market replacement value at the time of destruction may be reconstructed and used only in conformity with all the provisions of this chapter, except that a nonconforming structure may be reconstructed utilizing the existing building foundation and footprint where the nonconforming front, side and rear building setbacks are at least 75% of the required minimum setbacks for the zone district and otherwise comply with the requirements of Subsection 20-18.1c.

Nothing contained herein shall prevent the restoration of a wall, or other structural component declared unsafe by the Construction Official. Such emergency repairs are not subject to the 50% market value requirement in paragraph a above.