(a) No duty on the part of the lessor shall arise under Section 1941 or 1942 if the lessee is in substantial violation of any of the following affirmative obligations. (1) To keep that part of the premises which he occupies and uses clean and sanitary as the condition of the premises permits. (2) To dispose from his dwelling unit all rubbish, garbage and other waste, in a clean and sanitary manner. (3) To properly use and operate all electrical, gas and plumbing fixtures and keep them as clean and sanitary as their condition permits. (4) Not to permit any person on the premises, with his permission, to willfully or wantonly destroy, deface, damage, impair or remove any part of the structure or dwelling unit or the facilities, equipment, or appurtenances thereto, nor himself do any such thing. (5) To occupy the premises as his abode, utilizing portions thereof for living, sleeping, cooking or dining purposes only which were respectively designed or intended to be used for such occupancies. (b) Paragraphs(1) and (2) of subdivision (a) shall not apply if the lessor has expressly agreed in writing to perform the act or acts mentioned therein.