With respect to residential property:

(a) A landlord shall:

(1) At the commencement of a tenancy, deliver the dwelling unit and surrounding premises in a fit and habitable condition, and shall thereafter maintain the leased property in such condition; and

(2) Maintain the leased property in a condition that meets requirements of applicable health, safety, fire and housing codes, unless the failure to meet those requirements is the fault of the tenant, a member of his family or other person on the premises with his consent; and

(3) In multiple housing units, keep clean, safe and in repair all common areas of the premises remaining under his control that are maintained for the use and benefit of his tenants; and

(4) Make all repairs necessary to keep the premises in a fit and habitable condition, unless said repairs were necessitated primarily by a lack of reasonable care by the tenant, a member of his family or other person on the premises with his consent; and

(5) Maintain in good and safe working order and condition all electrical, plumbing, sanitary, heating, ventilating, air- conditioning and other facilities and appliances, including elevators, supplied or required to be supplied by him by written or oral agreement or by law; and

(6) In multiple housing units, provide and maintain appropriate conveniences for the removal of ashes, garbage, rubbish and other waste incidental to the occupancy of the dwelling unit; and

(7) With respect to dwelling units supplied by direct public utility connections, supply running water and reasonable amounts of hot water at all times, and reasonable heat between October 1, and the last day of April, except where the dwelling unit is so constructed that running water, heat or hot water is generated by an installation within the exclusive control of the tenant.

(b) If a landlord's duty under the rental agreement exceeds a duty imposed by this section, that portion of the rental agreement imposing a greater duty shall control.

(c) None of the provisions of this section shall be deemed to require the landlord to make repairs when the tenant is in arrears in payment of rent.

(d) For the purposes of this section, the term "multiple housing unit" shall mean a dwelling which contains a room or group of rooms located within a building or structure forming more than one habitable unit for occupants for living, sleeping, eating and cooking.