The volume of empty space within the profile of a sloping roof is attic space - free space created by the roof structure. It's also great space for the storage of many things. Attic garage plans rarely have a code compliant stairway access. In the code, attic access is defined as a simple access with a removable or built-in panel, manufactured fold down attic stair assembly. They typically fit between the bottom truss chords or ceiling joists if present. Behm Design offers many garage plans which include attic spaces due to the use of attic-type trusses or the arrangement of rafters and ceiling joists (the attic floor).
Some local authorities have limits on vertical height within the attic so it is worth verifying. Their intention is to prevent the building/adapting of attics as dwelling space (such as apartments). It is advisable to check with your local authority regarding allowable attic space, just in case it is a local issue.
Also view our collection of utility garage plans