30 x 22 however irc m1305 1 3 regarding the attic passageway access not attic access is not as clear because it uses two different dimensions in relation to the term opening used twice in the same paragraph.
Attic access irc.
Attics that meet the size and ceiling height criteria of the habitable attic definition in chapter 2 are considered habitable.
The 2012 international residential code requires an attic access opening for attics with an area greater than 30 square feet and a vertical height in excess of 30 inches.
Section r807 attic access r807 1 attic access.
Buildings with combustible ceiling or roof construction shall have an attic access.
Irc 807 1 is clear to me with its dimensions for attic access.
This is applicable to finished and unfinished spaces.
The 2009 and 2015 irc verbiage is similar and still applicable.
Habitable attics require a vertical access and emergency escape and rescue opening.
See section m1305 1 3 for access requirements where mechanical equipment is located in attics.
Irc 12 13 section r807 1 proponent.