This chapter talks about green building materials that are healthy for the interior environment, outdoor environment, minimize building energy use, low-embodied energy, and are durable, reusable, recyclable, and biodegradable, obtained locally. Applicable building codes and standards limit the choice of materials and assemblies for dwellings and most types of commercial buildings. Traditional concrete is one of the most inert building materials; it is also a good product from an indoor air quality standpoint. Sometimes metals are just one of several viable material choices, in which case it is instructive to compare options. Other building materials such as wood, plastics are discussed in the chapter. The designer evaluates the potential for condensation in each unique building envelope assembly over the annual outdoor temperature range and build forgiveness into the system. Green building design is an integrated, holistic process with a goal greater than the sum of its individual material components.