§ 28. Two or more buildings on same lot. 1. If any separate multiple
dwelling is erected after April eighteenth, nineteen hundred
twenty-nine, upon the rear of a lot which has another multiple dwelling
on the front or upon the front of a lot which has another multiple
dwelling on the rear, access shall be provided to the rear dwelling from
a street by means of an unobstructed court at least twenty feet in
width.

2. Except as otherwise provided for motor vehicle storage space in
section sixty and for dwellings erected, enlarged, converted or altered
pursuant to plans filed prior to December fifteenth, nineteen hundred
sixty-one in accordance with the provisions of subdivision one of
section twenty-six, if any building or dwelling is placed on the rear of
the same lot with a multiple dwelling or a multiple dwelling is placed
anywhere on the same lot with another building, there shall be left
between the two buildings an open space unoccupied from the ground up
and at least forty feet in depth, measured in the direction from one
building to the other for the first one hundred twenty-five feet above
the curb level, and eighty feet above that point. The provisions of this
subdivision requiring an open space eighty feet in depth between
portions of buildings in excess of one hundred twenty-five feet above
the curb level shall not be applied when both such portions are towers.

3. If on the rear of a lot any such building or any portion thereof is
used for business purposes, a separate passageway at least three feet
six inches wide and seven feet high shall be provided leading from every
such open space adjacent to such building to a street. No such
passageway shall connect with, go through or form a part of any entrance
hall or other public hall of a multiple dwelling upon the front of the
lot.