Answer:
at least 22 inches by 30 inches.
Explanation:
For an attic space, there should be an opening to that space at least 22 inches by 30 inches (22' × 30'), and a clear, unobstructed passageway large enough to allow removal of the mechanical appliance such as an air conditioner unit.
An attic can be defined as a space or room which is found just directly below the roof of a house. An attic is a space that is often used by people to store items. It is also generally being referred to as a garret or sky parlor and sometimes it is called a loft.
According to the 2012 International Residential Code, an attic is required to have an opening space of at least 22 inches wide and 30 inches high.