When specifically listed as an allowed or conditional use, zero-lot-line development may be permitted in residential districts, but shall be guided by the following:

1. SUBDIVISIONS. A new subdivision may include zero-lot-line lots. Subdivision developments of more than ten (10) lots shall be limited to fifty percent (50%) of its total lots for zero-lot-line. Lot sizes for each zero-lot-line lot shall be one-half of the minimum size for a two-family dwelling as specified for the zone district in which the subdivision is to be developed. Yard regulations shall comply with sub-section C below.
2. INDIVIDUAL LOTS AND DUPLEX CONVERSIONS. Platted lots, not in new subdivisions, may be developed for zero-lot-line use, and two-family structures existing at the time of passage of this ordinance may be converted to separate ownership for zero lot line (twin home) use. New construction on existing lots shall comply with lot development regulations, sub-section C below. For the conversion of existing duplex buildings to twin home use, minimum lot size requirements shall not apply. However, all appropriate building code requirements for condominium construction shall be strictly enforced.
3. DEVELOPMENT REGULATIONS
   1. Minimum Lot Size. The minimum lot size for each zero-lot-line lot shall be one-half (½) the minimum size allowed for a two-family dwelling in the zone district.
   2. Yard Regulations
      1. Front Yards: Same as the zone district.
      2. Side Yard: The side yard shall be at least twenty percent (20%) of the lot frontage, or ten feet (10’), whichever is greater. On corner lots, the zero side yard shall never occur on the street side.
      3. Rear Yard:  Same as the zone district.
      4. Lot Coverage: No more than fifty percent (50%) of the lot may be occupied by the building.
      5. Lot Frontage:  eighty foot (80’) minimum.
   3. Other Regulations
      1. Openings on the Zero-Yard Side: On detached buildings, no windows, doors, or other openings shall be allowed on the zero-yard side.
      2. Parking: A minimum of two (2) off-street parking spaces shall be provided on each platted lot.
      3. Lots Bordering Standard Lots: Where a zero-lot-line lot borders a standard (non-zero-lot-line) lot, the zero-yard side shall be opposite the abutting lot line.