The rim or counter surface shall be no higher than ________ inches above the finished floor on a handicapped accessible lavatory.

The designated height for the rim or counter surface of a handicapped accessible lavatory is set to ensure that individuals with disabilities can use the fixtures comfortably and safely. The maximum height of 34 inches above the finished floor, as indicated by the correct answer, aligns with accessibility standards that promote equitable access for people who may be in wheelchairs or require other accommodations.

This height is established based on universal design principles, ensuring that users can reach the faucet and wash basin without unnecessary strain. Avoiding excessive height is crucial not only for functionality but also for compliance with regulations such as the Americans with Disabilities Act (ADA), which aims to create accessible environments.

Other heights listed, such as 36, 31, and 29 inches, do not meet these specific accessibility recommendations. Heights greater than 34 inches could impede accessibility for many users, while those significantly lower than 34 inches, like 29 inches, may not provide adequate space for wheelchair users to approach comfortably. Thus, maintaining the height at 34 inches strikes the right balance between the needs of various users and the requirements of plumbing codes.