36 CFR Parts 1190 and 1191 ADA and ABA Accessibility Guidelines - Preamble (Discussion of Comments and Changes)

Comment. Section 404.2.5 addresses the height of thresholds. A maximum height of ½ inch is generally specified, although an exception permits a maximum height of ¾ inch at existing or altered thresholds that have a beveled edge on each side. Many comments opposed any threshold height above ½ inch. Conversely, a few comments urged that this exception be broadened to restore a similar allowance for exterior sliding doors.

Response. The Board has retained the ¾ inch height allowed for thresholds with a beveled edge on each side that are existing or altered because compliance with the ½ inch requirement can, in some cases, significantly increase alteration costs and necessitate replacement of door assemblies. An exception in original ADAAG that allowed a ¾ inch threshold at exterior sliding doors was removed in the proposed rule because products are available, including swinging doors, that meet the ½ inch maximum specified for all other doors. No changes to the criteria for thresholds have been made in the final rule.