What is the definition of a building sewer?

The building sewer is defined as the section of pipe that begins outside a building's foundation wall and extends to the public sewer system or private sewage disposal system. This is a crucial component of a plumbing system as it serves as the conduit for wastewater generated from within the building to be safely transported away from the premises.

In this context, the building sewer includes various components, such as the pipes and any associated fittings, that facilitate the movement of wastewater. The point at which it begins—just outside of the building's foundation—marks the transition from the internal plumbing system of the building to the external sewer infrastructure.

Understanding this definition is essential for various plumbing applications, including installation practices, maintenance, and identifying potential issues related to compliance with building codes and regulations. The other options provided do not accurately capture this definition, as they focus on specific elements of plumbing systems that do not encompass the entire scope of what a building sewer entails.