Two-Family Residential Subdistricts, as indicated by the designation 2F on said Maps. The Two-Family Residential Subdistricts are established to preserve, maintain, and promote two-family neighborhoods, to preserve existing structures, to provide for new infill construction appropriate to the existing fabric, and to allow minor changes to occur as-of-right. In a 2F subdistrict the maximum number of Dwelling Units allowed in a single Building shall be 2; a greater number up to 3 units in a Building shall be conditional.