ADA Accessibility Guidelines for Buildings and Facilities (ADAAG), 2004

Chapter 3: Building Blocks
Section 303: Changes in Level

303 Changes in Level

303.1 General. Where changes in level are permitted in floor or ground surfaces, they shall comply with 303.

EXCEPTIONS: 1. Animal containment areas shall not be required to comply with 303.

2. Areas of sport activity shall not be required to comply with 303.

303.2 Vertical. Changes in level of 1/4 inch (6.4 mm) high maximum shall be permitted to be vertical.

FIGURE 303.2 Vertical Change in Level
Elevation drawing of a change in level between the surfaces of two parallel planes with a vertical edge that is 1/4 inch (6.4 mm) high maximum.

303.3 Beveled. Changes in level between 1/4 inch (6.4 mm) high minimum and 1/2 inch (13 mm) high maximum shall be beveled with a slope not steeper than 1:2.

Advisory 303.3 Beveled. A change in level of 1/2 inch (13 mm) is permitted to be 1/4 inch (6.4 mm) vertical plus 1/4 inch (6.4 mm) beveled. However, in no case may the combined change in level exceed 1/2 inch (13 mm). Changes in level exceeding 1/2 inch (13 mm) must comply with 405 (Ramps) or 406 (Curb Ramps).

FIGURE 303.3 Beveled Change in Level
Elevation drawing of a change in level 1/4 to 2 inches (6.4 - 13 mm) high that is beveled with a slope of 1:2.

303.4 Ramps. Changes in level greater than 1/2 inch (13 mm) high shall be ramped, and shall comply with 405 or 406.