Cal. Civ. Code § 410.420
Habitability Requirements
Operative Text
(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.Section 410.420 of the Massachusetts Sanitary Code establishes minimum physical standards for habitable space in residential settings. Rooms affected by excess moisture cannot be used for habitation, and ceiling height thresholds determine whether floor area counts as habitable. The rule also sets specific square footage floors: at least 150 square feet for a unit's first occupant and 100 square feet for each additional occupant, with separate minimums for sleeping rooms and single-occupancy rooming units.
Plain English — not legal advice.
Operators of residential properties in Massachusetts must ensure that every unit meets the space and condition standards set out in 105 CMR 410.420 before allowing occupancy. A compliant operator calculates habitable floor area by excluding any space with a ceiling height under five feet and verifies that no room where more than three-quarters of the floor area falls below seven feet of ceiling height is offered as habitable. Landlords also track occupancy counts carefully, since the minimum square footage requirements scale with the number of occupants and differ for sleeping rooms versus general living space.
General guidance for property managers — not legal advice for your specific situation. Consult an attorney for advice on your case.
Under 105 CMR 410.420, tenants have a right to live in space that meets defined minimums for size, ceiling height, and moisture conditions. If a unit appears to fall short—for example, a sleeping room that seems too small, or a room with persistent dampness—tenants can document the conditions and file a complaint with the local board of health, which enforces the Massachusetts Sanitary Code. Tenant-rights organizations can also help residents understand how these habitability standards may be raised as a defense in eviction proceedings or rent-withholding situations.
General guidance for tenants — not legal advice for your specific situation. Consult a tenant-rights organization or attorney for advice on your case.
Generated September 30, 2026 — auto-generated, not yet human-reviewed. See /transparency for methodology.
Effective Timeline
References Out
No outbound references recorded yet for this provision.
References In
No inbound references recorded yet for this provision.