§ 63. Sub-curb uses. 1. When any living room is below the level of the highest curb in front of any multiple dwelling erected after April eighteenth, nineteen hundred twenty-nine, in accordance with the provisions of paragraph f of subdivision one of section thirty-four, all portions of such dwelling below such level shall be fireproof throughout except that windows therein need not be fireproof but shall be of incombustible material and may be glazed with plain glass.

2. Except in multiple dwellings which do not exceed eighty feet in height measured from the lowest point of any curb on which any part of the dwelling faces, at least one means of egress from any apartment or suite of rooms below the level of the highest curb in front of such a dwelling shall lead directly to the street in front of said dwelling and at least one such means to the yard or street in the rear of said dwelling. Every yard in the rear of every such multiple dwelling, regardless of the height of such dwelling, shall at the lowest level of such yard be provided with a fire passage in compliance with the requirements for such a passage in paragraph f of subdivision five of section twenty-six.

3. Notwithstanding any other provisions of this section the department may require such additional means of egress from the said dwelling or protection from fire as the department may deem necessary for the safety of the occupants.