(a) A landlord shall:

(1) comply with the requirements of applicable building and housing codes materially affecting health and safety;

(2) make all repairs and do whatever is reasonably necessary to put and keep the premises in a fit and habitable condition;

(3) keep all common areas of the premises in a reasonably safe condition, and, for premises containing more than four dwelling units, keep in a reasonably clean condition;

(4) make available running water and reasonable amounts of hot water at all times and reasonable heat except where the building that includes the dwelling unit is not required by law to be equipped for that purpose, or the dwelling unit is so constructed that heat or hot water is generated by an installation within the exclusive control of the tenant and supplied by a direct public utility connection;

(5) maintain in reasonably good and safe working order and condition all electrical, gas, plumbing, sanitary, heating, ventilating, air conditioning, and other facilities and appliances, including elevators, supplied or required to be supplied by him. Appliances present in the dwelling unit are presumed to be supplied by the landlord unless specifically excluded by the rental agreement. No appliances or facilities necessary to the provision of essential services may be excluded.

(b) If the duty imposed by paragraph (1) of subsection (a) is greater than any duty imposed by any other paragraph of that subsection, the landlord's duty must be determined by reference to paragraph (1) of subsection (a).

(c) The landlord and tenant of a single family residence may agree in writing that the tenant perform the landlord's duties specified in paragraph (5) of subsection (a) and also specified repairs, maintenance tasks, alterations, and remodeling, but only if the transaction is entered into in good faith and not for the purpose of evading the obligations of the landlord.

(d) The landlord and tenant of any dwelling unit other than a single family residence may agree that the tenant is to perform specified repairs, maintenance tasks, alterations, or remodeling only if:

(1) the agreement of the parties is entered into in good faith and not for the purpose of evading the obligations of the landlord;

(2) the work is not necessary to cure noncompliance with subsection (a)(1) of this section;

(3) the agreement does not diminish or affect the obligations of the landlord to other tenants in the premises.