A plumber is retrofitting an existing washroom to meet barrier-free standards. The current lavatory is pedestal-mounted. To comply with CSA B651 for accessible lavatories, what specific requirement must be met regarding knee clearance?

Question: A plumber is retrofitting an existing washroom to meet barrier-free standards. The current lavatory is pedestal-mounted. To comply with CSA B651 for accessible lavatories, what specific requirement must be met regarding knee clearance?

Answer options:

• A minimum of 500 mm clear knee space below the lavatory, measured from the finished floor. ✅ A minimum of 685 mm clear knee space below the lavatory, measured from the finished floor to the bottom of the apron.
• A maximum depth of 400 mm for the lavatory basin to ensure reach.
• The lavatory must be wall-mounted with exposed piping for easy access.

Correct answer: A minimum of 685 mm clear knee space below the lavatory, measured from the finished floor to the bottom of the apron.

Explanation: CSA B651 specifies a minimum clear knee space of 685 mm (27 inches) from the finished floor to the bottom of the lavatory apron for accessibility. Options A and C provide incorrect dimensions, and while wall-mounted is common for accessibility, the primary requirement is the knee clearance, not necessarily exposed piping.