§ 142. Sub-curb uses. 1. When such a dwelling is more than eighty feet
in height measured from the lowest point of the yard or of any curb on
which any part of the dwelling faces, whichever is lower, and any room
in such dwelling below the level of the highest curb which any part of
such dwelling faces is occupied for living purposes as permitted in
paragraph f of subdivision one of section thirty-four, the yard at the
level of such highest curb shall be set back so as to be at least eight
feet greater in depth than the yard below such level unless the yard
opens directly upon a street.

2. If such a dwelling is erected upon an interior lot running through
from street to street, the wall of the dwelling facing the lowest street
shall, at the level of the highest curb on which any part of such
dwelling faces, be set back at least eight feet.

3. The setback of the yard or wall required by each of the two
preceding subdivisions shall be a fire-terrace. Nothing herein contained
shall be construed to permit a yard of smaller dimensions below the
level of such fire-terrace than required by paragraph f of subdivision
one of section thirty-four.

4. From each apartment below the level of such highest curb at least
one means of egress shall lead directly to such fire-terrace in a manner
approved by the department. Such fire-terrace shall be protected by a
guard railing approved by the department, and shall afford safe and
unobstructed access either directly to a street or to a covered
fireproof passage at least three feet in width and seven feet in height
leading directly and without obstruction to a street.

5. In all portions of such dwellings below the level of the highest
curb all structural members, partitions, furrings and ceilings shall be
constructed of incombustible materials.

6. Apartments may also be occupied for living purposes in cellars and
basements in accordance with the provisions of subdivision six of
section thirty-four.