Any and all preservation districts, floodplain districts, and historic districts described in this chapter shall be interpreted and enforced as map overlays to the existing districts as shown on the Official Zoning Map of the Borough of Bath and, as such, the provisions of these zones shall serve as a supplement to the rules, regulations, and ordinances pertaining to those underlying districts. Where any conflict exists between the provisions of the aforementioned sections and the underlying districts, the more restrictive provision shall be applied.