Buildings cannot be energy efficient if the building enclosure does not function at a high level. The enclosure (the six sides of the structure) functions to protect the occupants and contents from the natural exterior environment. It consists of many materials with various functions and aesthetics, installed on the building by a variety of methods & means. Some materials will be visible, others hidden, but they all should be durable. The various materials are defined as to their quantity and position on the building. They are installed on the building by a variety of methods & means. The commissioning process must begin during the early design phase. The commissioning review of the drawings will mostly focus on the details of the enclosure, referenced on the building floor plans, elevations, and wall sections. Exterior wall mock-up testing is important to exterior wall and fenestration commissioning before the construction phase. George will share details on quality assurance visual inspections and on-site performance verification testing, which are vital to a successful commissioning program.