§ 79. Heating. 1. Every multiple dwelling exceeding two stories in height and erected after April eighteenth, nineteen hundred twenty-nine, and every garden-type maisonette dwelling project erected after April eighteenth, nineteen hundred fifty-four, shall be provided with heat. On and after November first, nineteen hundred fifty-nine, every multiple dwelling shall be provided with heat or the equipment or facilities therefor. During the months between October first and May thirty-first, such heat and the equipment or facilities shall be sufficient to maintain the minimum temperatures required by local law, ordinance, rule or regulation, in all portions of the dwelling used or occupied for living purposes provided, however, that such minimum temperatures shall be as follows: (a) sixty-eight degrees Fahrenheit during the hours between six o'clock in the morning and ten o'clock in the evening, whenever the outdoor temperature falls below fifty-five degrees Fahrenheit, notwithstanding the provisions of paragraph a of subdivision four of section three of this chapter, and (b) at least fifty-five degrees Fahrenheit during the hours between ten o'clock in the evening and six o'clock in the morning, whenever the outdoor temperature falls below forty degrees Fahrenheit. Nothing in this section shall be deemed to relieve any owner of the duty of providing centrally supplied or other approved source of heat prior to November first, nineteen hundred fifty-nine in any case where such heat is required by this chapter or any other law, ordinance, rule or regulation to be supplied in a dwelling prior to said date. The heating system in dwellings used for single room occupancy shall be in conformity with the requirements of section two hundred forty-eight.

2. The provisions of subdivision one shall not apply to any dwelling (a) which is located in a resort community and is rented or occupied on a seasonal basis between April fifteenth and October fourteenth during any calendar year and is not occupied for living purposes during the remainder of such year, except that occupancy of any such dwelling by the family of a caretaker thereof or by the family of the owner thereof during the remainder of the year shall be permitted; or (b) which the department of city planning certifies is in an area to be acquired for a public improvement or for development or redevelopment and for which (1) a request for acquisition has been submitted to the mayor by a public agency or (2) a plan for a development or redevelopment project has received preliminary or first approval of the city planning commission; or (c) for which a demolition permit has been or shall be issued by the municipality pursuant to local law or ordinance.

3. The exemption provided in subdivisions two (b) and two (c) of this section shall be valid for a period of six months after the date of the approval of the slum clearance or urban renewal plan or the date of such certification or the date of the issuance of the demolition permit, as the case may be, but such exemption may be extended from time to time by the department provided, however, that such exemption shall not extend beyond November first, nineteen hundred sixty-one.