The simplest way to ensure that all elements of your air barrier system connect up is to take a footing-to-ridge cross section drawing of your building and connect the air barrier from the footing to the ridge without lifting your pencil or cursor. Typically, the tough spots will be transitions from one assembly to another (for example foundation to above-grade wall) and penetrations like windows and dormers. These details are a part of that process, keeping the pencil or cursor flowing from footing to ridge (or top floor ceiling).