ABA Accessibility Standard for GSA Facilities Pocket Guide

F206.2.3.1 Stairs and Escalators in Existing Buildings.

In alterations and additions, where an escalator or stair is provided where none existed previously and major structural modifications are necessary for the installation, an accessible route shall be provided between the levels served by the escalator or stair unless exempted by F206.2.3 Exceptions 1 through 6.