On any nonconforming structure or portion of structure, and on any structure containing a nonconforming use, work may be done on ordinary repairs, or on repair or replacement of walls, fixtures, wiring, or plumbing, or other parts, provided that the cubic content of the nonconforming structure or portion shall not be increased. Nothing in this chapter shall be deemed to prevent the strengthening, repairing, or restoring to a safe condition of any structure or part thereof.
(Prior Code, § 4.4)