The requirements of this Title as to minimum Lot area or Lot Width shall not be construed to prevent the Use for a Single Unit Dwelling on any legally approved Lot or Parcel of Land. Combination of several Lots under common ownership can be considered a buildable Lot, but Lots originally under common ownership and subdivided are not buildable Lots unless the Subdivision is approved and recorded in accordance with this Title. Such Lot or Parcel of Land must be located in a zone which permits Single Unit Dwellings, have access to a dedicated Street, and be a legally divided Lot held in separate ownership at the time such requirements became effective for such Lot or Parcel of Land, as determined pursuant to Section 7-1-107.