When a multiple dwelling is erected, said multiple
dwelling shall not exceed six stories or 75 feet in height, shall
not provide for more than 105 dwelling units on an acre of land, or
not more than a proportionate number of dwelling units on any fractional
part of an acre of land, and shall not be erected unless the plot
or parcel on which said multiple-dwelling building is to be erected
shall be at least two acres in area and shall have frontage on three
public streets.
The number of units within a multiple dwelling which
are used for any nonresidence purposes shall not exceed 10% of the
total number of units in that multiple dwelling.