105 CMR 410.420
Habitability Requirements
(A) No room or area in a residence may be used for habitation if it is subject to excess moisture.
(B) No room shall be considered habitable if more than ¾ of its total floor area has a
floor-to-ceiling height of less than seven feet.
(C) No area of a room where the ceiling height is less than five feet shall be considered
habitable space required by 105 CMR 410.420(D).
(D) Minimum Square Footage.
(1) Every dwelling unit shall contain at least 150 square feet of habitable floor space for its
first occupant, and at least 100 square feet of habitable floor space for each additional
occupant.
(2) A rooming unit shall contain a minimum of 100 square feet of habitable floor space
when:
(a) The unit contains one single room for living and sleeping only; and
(b) Is occupied by no more than one person.
(3) In every residence, each room used for sleeping purposes by one occupant shall contain
at least 70 square feet of floor space.
(4) In every residence, each room used for sleeping by more than one occupant shall contain
at least 50 square feet of floor space for each occupant.
(5) Homeless shelters are exempt from 105 CMR 410.420(D)(1) through (4) but must
provide an alternating sleeping configuration to allow for six feet of separation head to head
between bed occupants, wherever feasible.