What is the maximum height required for knee clearance depth at a height of 9 inches?

In plumbing design, particularly regarding fixtures and accessibility, knee clearance is an important consideration for ensuring that spaces under sinks or work surfaces are usable and comfortable for individuals, including those who may use wheelchairs. For a knee clearance depth required at a height of 9 inches, the regulations typically stipulate that the clearance should be sufficient to accommodate various needs.

The maximum height required for knee clearance depth at a height of 9 inches is generally defined to provide adequate space for knees to fit comfortably without obstruction. In this case, a height of 11 inches aligns with standard accessibility guidelines, which often specify that the minimum clearance should support typical user requirements around knee, leg, and foot positioning.

The other options for maximum height do not fit within this guideline. Heights of 10, 12, and 9 inches would not provide the optimal space recommended for user comfort and accessibility. Therefore, the choice of 11 inches as the maximum height ensures compliance with safety and usability standards for plumbing fixtures.