Which appliance typically requires a dedicated drainage line?

A toilet typically requires a dedicated drainage line due to the nature of its function and the volume of waste it handles. Toilets generate a significant amount of water and solid waste, which necessitates a direct and unobstructed pathway to the building's sewer or septic system. This dedicated drainage line helps to prevent clogs and ensures that waste is efficiently removed, promoting sanitary conditions within the plumbing system.

Kitchen sinks and washing machines can share drainage lines with other fixtures, provided that proper venting and trap configurations are in place. A bidet, while it does require a drainage connection, is usually installed in proximity to an existing toilet drainage line. In contrast, toilets are uniquely positioned to necessitate their own dedicated lines for optimal function and to meet code requirements.