2006 New York Code - General Restrictions On Projections Beyond Street Line.

 
    §  26-225  General  restrictions on projections beyond street line. It
  shall be unlawful to construct any part  of  a  building  erected  after
  December  sixth,  nineteen  hundred  sixty-eight, or altered or enlarged
  after such date, so as to project beyond the street  line  and  encroach
  upon  a  public  street  or  public space, except in accordance with and
  subject to the provisions of this article  and  the  provisions  of  the
  building code. Any permission, express or implied, to construct any part
  of a building so as to project beyond the street line shall be revocable
  at  will by the city council or the board of estimate; and any part of a
  building permitted to  project  beyond  the  street  line  shall  be  so
  constructed  that  it  may  be  removed  at any time without causing the
  building to become structurally unsafe in whole or in part,  subject  to
  such exceptions and exemptions as may be provided in the building code.