Sec. 59-B-6.2. Existing buildings and structures.

   Any building or structure which was lawful under the Prince George's County Zoning Ordinance in effect on June 30, 1997, and was constructed within the Annexation Area under a building permit issued prior to February 10, 1998, is a conforming building or structure in Montgomery County and may be:

   (a)   altered, renovated, or enlarged in accordance with the Montgomery County Zoning Ordinance, or

   (b)   reconstructed after a fire, flood or similar event pursuant to the building permit for the property in effect prior to unification, if the property had a valid use-and-occupancy permit issued by Prince George's County prior to July 1,1997.