§ 65. Boiler rooms. 1. Except as hereafter provided, in every multiple dwelling erected after April eighteenth, nineteen hundred twenty-nine, which is four stories or more in height the boiler shall be enclosed in a room or space constructed with fireproof walls extending from the floor construction to the ceiling construction, and all openings therefrom to other portions of the dwelling shall be equipped with fireproof doors and assemblies with the doors self-closing. However, in all multiple dwellings, on and after January first, nineteen hundred sixty-six, a room or space provided with a central heating plant shall be completely enclosed with incombustible materials having a standard fire-resistive rating of at least one hour.

2. In such a dwelling access to a cellar or lowest story in which a boiler is located shall not be through any boiler room, nor shall any cellar or basement stair or any shaft be installed within a boiler room.

3. The department shall have the power to make supplementary regulations relating to boiler or furnace rooms.