What does BD refer to in residential plumbing?

In residential plumbing, BD stands for Building Drain. This term is crucial for understanding the drainage system within a building. The building drain is the part of the plumbing system that conveys wastewater from the building's plumbing fixtures to the building’s sewer or septic system. It is typically located below the fixtures and must be designed with appropriate slope and size to ensure efficient flow and prevent backflow.

Understanding the role of the building drain is vital for plumbing design and installation. It ensures that waste material is effectively carried away, maintaining hygiene and preventing plumbing issues like clogs or leaks. The term may also appear in various plumbing codes and regulations when discussing the requirements for draining systems in residential constructions.