Each building or part of a building that is constructed or altered by, on behalf of, or for the use of the Bureau shall be designed, constructed, or altered so as to be readily accessible to and usable by individuals with disabilities. The definitions, requirements, and standards of the Architectural Barriers Act (42 U.S.C. 4151-4157), as implemented in 41 CFR 101-19.600 through 101-19.607, apply to buildings covered by this section.