2006 New York Code - Existing Excessive Area.

 
    §  27-304  Existing  excessive area. Any building existing on December
  sixth, nineteen hundred sixty-eight that exceeds the  maximum  allowable
  area  permitted under the provisions of this section, may be enlarged if
  the addition is separated from the existing building by a fire  division
  meeting  the requirements of subchapter five of this chapter, and if the
  additional area does not exceed the limits established by tables 4-1 and
  4-2 for the specific occupancy group and construction class.