No room in any cellar shall be occupied for living purposes, except as provided in subdivision six of section thirty-four or in subdivision three of this section.
A room occupied for living purposes in a basement shall comply with the requirements of sections one hundred seventy-three and one hundred seventy-four except as provided in subdivision four of this section.
Where more than sixty per centum of the height of a cellar is below the level of the curb on which a dwelling faces, but the floor of such cellar is approximately at the level of the yard thereof and such yard is not less than thirty feet in depth at every point, the department may permit the use of such cellar for living purposes if it shall deem such cellar adequately lighted and ventilated and habitable. When permission is granted such a cellar shall be deemed a basement.
The basement of a converted dwelling may be used for living purposes without meeting the requirements of subdivisions one and two of section one hundred seventy-three if such dwelling meets the other applicable requirements of such section and of this chapter, including the following:
a. Such a dwelling shall not exceed three stories, including the basement, in height.
b. It shall be occupied by not more than one family on any story, including the basement. For the purposes of this subdivision a family shall not be deemed to include any boarders, lodgers or roomers.
c. It shall have at least one court two feet or more in width extending across the entire depth of the lot from the street to the yard.
d. The department shall deem the basement to be adequately lighted and ventilated, free of any dampness, sanitary and habitable.
e. There shall be a separate water-closet compartment within the basement apartment conforming to the provisions of section two hundred.
f. Such dwelling shall not be required to comply with section one hundred eighty-seven if a scuttle is provided conforming to section one hundred eighty-eight.
(g) This subdivision is applicable only to buildings noted, classified or recorded as such converted dwellings in the department prior to January first, nineteen hundred sixty-six.
Notwithstanding any provisions of this section or of subdivision five of section three hundred, an apartment or room in a cellar which was occupied for living purposes at any time on or after October first, nineteen hundred fifty-two may thereafter continue to be occupied for such purposes until July first, nineteen hundred sixty-seven in accordance with the conditions imposed by subdivision five of section two hundred sixteen.