Section 27-2005. Duties of owner

a. The owner of a multiple dwelling shall
  keep the premises in good repair.
    b. The owner of a multiple dwelling, in addition to the  duty  imposed
  upon  such  owner by subdivision a of this section, shall be responsible
  for compliance with the requirements of this  code,  except  insofar  as
  responsibility for compliance is imposed upon the tenant alone.
    c.  The owner of a one- or two-family dwelling shall keep the premises
  in good repair,  and  shall  be  responsible  for  compliance  with  the
  provisions  of  this code, except to the extent otherwise agreed between
  such owner and any tenant of such dwelling by lease or other contract in
  writing, or except insofar as responsibility for  compliance  with  this
  code is imposed upon the tenant alone.
    d.  The  owner  of  a dwelling shall not harass any tenants or persons
  lawfully entitled  to  occupancy  of  such  dwelling  as  set  forth  in
  paragraph 48 of subdivision a of section 27-2004 of this chapter.