Natural and Mechanical Ventilation
Effective Jun 23, 2023Mass. Register #1498MGL c. 111, § 3 MGL c. 111, § 127ADepartment of Public Health
(A) Habitable rooms, and rooms with a toilet, bathtub or shower shall have:
- (1) Windows, skylights, or doors through the exterior walls or roofs that can be easily opened with a combined opening of at least 4% of the floor area of that habitable room or room containing a toilet, bathtub or shower; or
- (2) Mechanical ventilation capable of exhausting air to the outdoors.
- (B) When the board of health has determined that natural ventilation is insufficient to remove excess moisture, mechanical ventilation is required.
- (C) Mechanical ventilation shall be installed and maintained in accordance with 780 CMR: Massachusetts State Building Code.
- (D) Each mechanical ventilation system shall be equipped with a readily accessible means for shut-off, unless such system is designed to run constantly or is barometrically controlled.