Attic Access Rules
Most homeowners spend as little time as possible up in the attic. In summer, an unconditioned attic is a broiling oven; during winter it’s a frigid void. Attic space, however, is commonly utilized for storage as well as equipment installations like heating-system air handlers, whole-house humidifiers and dehumidifiers and attic exhaust fans. For these reasons -- as well as a safety precaution in the event of an attic fire -- proper attic access from the living spaces below is important. The International Code Council, which sets building safety and fire prevention codes that form the basis for local codes in all 50 states, specifies minimum attic access standards.
Attic Access Dimensions
Homes with attics that exceed 30 square feet and at least 30 inches in height must provide interior attic access. The access opening should be located in a hallway or other accessible spot. Ceiling access must be constructed to minimum dimensions of 22 inches by 30 inches, with at least 30 inches of headroom in the attic above the opening. Attic access situated in a wall must be no smaller than 22 inches wide by 30 inches high.
Equipment In Attics
Where an attic houses heating, ventilation and air conditioning or other mechanical equipment, access must be sufficient to permit the largest unit in the attic to be removed and never smaller than 30 inches by 22 inches. A passageway of solid flooring leading to the equipment should be at least 24 inches wide. Equipment installed in the attic should be surrounded by a level service space 30 inches wide and 30 inches deep.