Continuity of the air and water-resistant barrier (AWB) is critically important in high-performing buildings. Achieving continuity of these barriers at interfaces of different material systems is often a challenge. It becomes more challenging when the different barriers are installed in a nontraditional order within the building envelope or when penetrations are added after the AWB has been installed. This paper looks at the design and installation of tested, durable transitions between the AWB and other systems, including considerations for the window interface when the AWB is installed outboard of the continuous insulation, when the insulation is installed behind the exterior sheathing and AWB, and when the continuous insulation is also the AWB in commercial construction. The paper also examines the effects of the AWB being in or out of plane with the windows and the effects of the sequencing of window installation, specifically what happens when the window is installed either before or after the AWB. Options to reduce the number of fastener penetrations to the AWB before cladding installation are also shown. All discussed interface details are based on results from advanced system testing using a sequence of multiple ASTM test methods for air and water penetration before and after structural and thermal conditioning. In addition to interfaces in place prior to the installation of the AWB, penetrations are often installed after the AWB. One of the most frequent penetrations is for cladding attachments such as girt systems and when continuous insulation is installed. This paper presents an overview of results from testing conducted to determine how best to attach girt systems to continuous insulation that is also performing as the AWB along with an introduction to new innovations that ensure long-term water tightness when installing continuous insulation over an AWB.