Simply put, a new home’s building shell is comprised of the structural elements that separate the inside from the outside: walls, roofs, windows, doors. The shell’s function, however, is anything but simple. It has to protect its occupants from rain, wind and snow. It has to control the flow of energy and heat between indoors and outdoors. It has to control the flow of air and moisture. It has to provide light and a mechanism to enter and exit. It has to provide a means for pollutants and contaminants to flow out of the building. It has to create an environment that is comfortable indoors, when conditions outdoors are not. And, it significantly determines the affordability and energy consumption of a home. This program presents practical techniques building professionals can use to achieve all of these goals and still provide healthy IAQ.