2019 California Standards for Accessible Design Guide (effective January 1, 2020 with July 1, 2021 amendments)

11B-407.4.6.2 Buttons.

Car control buttons with floor designations shall comply with Section 11B-407.4.6.2.

Exception: Reserved. 

[2010 ADA Standards] EXCEPTION: In existing elevators, buttons shall be permitted to be recessed.

11B-407.4.6.2.1 Size and shape. Buttons shall have square shoulders, be ¾ inch (19.1 mm) minimum in their smallest dimension and be raised ¹/₈ inch (3.2 mm) plus or minus ¹/₃₂ inch (0.8 mm) above the surrounding surface.

[2010 ADA Standards] 407.4.6.2.1 Size. Buttons shall be ¾ inch (19 mm) minimum in their smallest dimension.

11B-407.4.6.2.2 Arrangement.

Buttons shall be arranged with numbers in ascending order. When two or more columns of buttons are provided they shall read from left to right.

11B-407.4.6.2.3 Illumination.

Car control buttons shall be illuminated.

11B-407.4.6.2.4 Operation.

Car control buttons shall be activated by a mechanical motion that is detectable.