Minimum floor area: 1,250 square feet. Every two-family dwelling unit structure in the Two-Family Residential District shall have a total combined floor area of no less than 1,500 square feet. Each dwelling unit in this district shall have a minimum of 2/3 of the required minimum floor area on the ground level (i.e., 1,000 square feet for single-family dwelling unit and 500 square feet for a multifamily dwelling unit).