Which of the following is NOT typically included in the building envelope?

The building envelope is a critical component of a structure designed to separate the interior environment from the exterior environment. It typically includes elements that provide insulation, support, and protection from the elements, such as the roof, exterior walls, and floors.

The roof serves as the top layer that shields against precipitation and weather conditions, while the exterior walls help maintain thermal performance and structural stability. Floors, particularly those at or above grade, play a role in separating the interior space from ground moisture or pests.

In contrast, plumbing systems are not considered part of the building envelope. They are essential for the building's functionality, providing water supply and drainage, but they do not contribute to the physical boundary that defines the interior and exterior of the building. By understanding this distinction, it becomes clear why plumbing systems are not included in the definition of the building envelope.