610.2 Bathtub Seats.
The top of bathtub seats shall be 433 mm (17″) minimum and 485 mm (19″) maximum above the bathroom finish floor. The depth of a removable in-tub seat shall be 380 mm (15″) minimum and 405 mm (16″) maximum. The seat shall be capable of secure placement. Permanent seats at the head end of the bathtub shall be 380 mm (15″) deep minimum and shall extend from the back wall to or beyond the outer edge of the bathtub.