The Information contained on this web page has been collected and presented as a guide. It should be used as a guide only and should not be relied upon as the sole source of information relating to ventilation requirements or legal requirements in any state or municipality. No warranty, either express or implied, is made with respect to the information contained herein. For additional information contact the specific state or municipality to obtain specific technical or legal ventilating requirements that may apply. Empire Ventilation Equipment Co., Inc. is not responsible for any loss, inconvenience, damage (whether special or consequential) or claims arising out of the use of the information contained on this page.
Buildings shall be provided with natural ventilation in accordance with section 1203.4, or mechanical ventilation in accordance with the International Mechanical Code.
1203.2 Attic Spaces. Enclosed attics and enclosed rafter spaces formed where ceilings are applied to directly to the underside of roof framing members shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain and snow. Blocking and bridging shall be arranged so as not to interfere with the movement of air. A minimum of 1 inch (25mm) of airspace shall be provided between the insulation and the roof sheathing. The net free ventilating area shall not be less than 1/150 of the area of the space ventilated, with 50 percent of the required ventilating area provded by ventilators located in the upper portion of the space to be ventilated at least 3 feet (914 mm) above eave or cornice ventilators with the balance required ventilation provded by eave or cornice ventilators.
1203.2.1 Openings in attic. Exterior openings into the attic space of any building intended for human occupancy shall be covered with corrosion-resistant white cloth screening, hardware cloth, perforated vinyl or similar material that will prevent the entry of birds, squirrels, rodents, snakes and other similar creatures. The openings therein shall be a minimum of 1/8 inch (3.2 mm) and shall not exceed 1/4 inch (6.4 mm). Where combustion air is obtained from an attic area, it shall be in accordance with chapter 7 of the International Mechanical Code.
1203.4 Natural ventilation. Natural ventilation of an occupied space shall be through windows, doors, louvers or other openings to the outdoors. The operating mechanism for such openings shall be provided with ready access so that the openings are readily controllable by the building occupants