The building envelope consists of all exterior components of a building –roof, walls, below-grade waterproofing, windows, skylights, and so on. When looking at these components it is important that each one be taken into consideration to prevent moisture or air from migrating into the building. The envelope is a complicated and integral part of any high performance building. However, it is often the most neglected portion. This presentation aims to educate the participants on the importance of the building envelope and how the individual components contained within the system must be designed, and constructed to ensure a long lasting, energy efficient building.