2006 New York Code - Two Or More Buildings On Same Lot.

 
    §  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.